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ss3079
07-06-2004, 11:33 PM
A few of our seasoned SPL vets wanted a thread where they could answer YOUR questions, regarding SPL competition.

How do I squeeze the extra 10th of a db out of my box? What can I do to make my current box better? Whatever your question is, as long as it's regarding SPL competition, post it here!

SQ guys get left out, again ;)

http://www.soundoff.org/events.htm
http://www.iasca.com/events/
http://www.nsplcompetition.com/mainpages/events.htm
http://www.termpro.com/asp/eventschedule1.asp
http://www.mecacaraudio.com/
http://www.slapshow.com/events/index.htm

I know they're links to the events pages ... but I'm sure you can find your way to the rules when Loyd or someone tells you to check out the rule page and doesn't supply a link :D ;)

- Steve

bigbassman
07-06-2004, 11:37 PM
yah.. I'll make it a point to visit this thread at least once a day...

and always keep in mind... every vehicle is different, every install is different.. what works in one car, may not in another.. thats the joy of competition SPL...

now ask away :)

Loyd L.

Bumpin' Yota
07-06-2004, 11:41 PM
ditto, Ill help out whenever possible. ;)

kickerlivinloud
07-06-2004, 11:45 PM
Ok me first....

My system is in my sig and I am wanting an all out SPL setup but still be able to plug it for daily drive. I plan on upgrading me alt and adding possibly upgrading my amps too. I was thinking, Orion 2500D, or a pair of MTX 81000D's but that is in the future. I am thinking about having 140^2 inches of port area but idk my when it comes to stuff like that. I was thinking around 40-50 for my daily setup. I want to have as much SQ for daily and as much SPL for comps as possible. Is 140^2 overkill or is it good or what???? Also is 45Hz a good SPL tuning. I know tuning higher is not always a garented raise in SPL so that is why I was...

Thanks in advance, glad a thread like this was finally made....


Jon

Randy Savage
07-07-2004, 12:44 AM
For SPL, a good start is the total Sd of the driver(s) for port area. Tuning is really dependant on the system/car. If you can get access to a meter for a little bit, may want to make adjustable ports with different tunings and see where you peak.

Hopefully that helps...good luck :)

Bumpin' Yota
07-07-2004, 12:57 AM
Ok me first....

My system is in my sig and I am wanting an all out SPL setup but still be able to plug it for daily drive. I plan on upgrading me alt and adding possibly upgrading my amps too. I was thinking, Orion 2500D, or a pair of MTX 81000D's but that is in the future. I am thinking about having 140^2 inches of port area but idk my when it comes to stuff like that. I was thinking around 40-50 for my daily setup. I want to have as much SQ for daily and as much SPL for comps as possible. Is 140^2 overkill or is it good or what???? Also is 45Hz a good SPL tuning. I know tuning higher is not always a garented raise in SPL so that is why I was...

Thanks in advance, glad a thread like this was finally made....


Jon



See this is the thing, I need to know what you have for a system. Your sig says IA DP 12/15.....also the same for amp so im assuming you are in the planning stages.

For starters 4.5 cubes would be a good start for the IA DP 15. I'd actually recommend a little bit smaller for the 12. Box size is going to also vary pending the amount of power you apply to the sub. The DP would come alive with about 2kw or more, so 2 mtx's would be a necessity.

Feeding the amps, you at least need a good deep cycle up front, so I'd recommend an Optima Blue Top Group 31 - proven loudest battery for burping with the engine off when you are sucking a lot of power from the battery.

Run 1/0. Do not skimp on it.

As far as port area that should work. The only box I've tried with the mentioned sub was 2.2 cubes tuned to 41hz with about 50sq in of port and 4400 watts rms. (No I couldn't get it to full excursion either.) Also another oddity, the box is dictating the loudest note, not my truck. This box is the same size withthe same port length, but I've been able to make my note go from 44hz to 47hz with some tweaking internally using angles and fiberglass and whatnot. This also gave me a bit of spl to boot.

If you have an SUV there are several ways to make a loud box. Typically the CRX box is the easiest to get loud. Loyd has a few other tricks I'm sure he is going to share....by firing the ports and subs back I hear? ;)

As far as what to tune to for SPL, that can only be determined by testing on the meter with different tunings.... The same can be said for direction of firing.

bigbassman
07-07-2004, 02:04 AM
eh.. I feel like a ramble..

there's 3 keys to being a winning competitor

winning meaning you can go to a large, sanctioned show, and bring home a first place trophy..

winning meaning holding state records, world records, and being world champion..

1. SPL meter
2. Electrical System
3. Being able to think on your own

number one is basic.. if you don't own, or have access to a good SPL meter.. might as well hang it up right there.. can't test what works if you have no meter.. ear doesn't play well in this area..

number two.. is sadly, the most overlooked portion of a vehicle...

sure.. you just bought 10 2 kw amps... whatcha gonna power them with? That stock alt and battery isn't gonna take kindly...

you NEED

1. Alternator(s)
2. Batteries
3. Large Wire

1. Alternator is duh... its the only device in a vehicle capable of producing power.. its used to supply the amps, supplement batteries to power amps, and recharge batteries in orgs where the vehicle must be off.. bigger is better..

2. Batteries.. yep.. can't run without them... if you have 600 amps of current draw from your amps... 1 200 amp alt isn't gonna float the boat.. I recommend something at least 900 cca, and with long warranties :)

3. Wire... usually overlooked.. verah bad.. ALWAYS upgrade the underhood wiring from the alternator (power and ground) and front battery (power and ground) the gains from doing that will astonish you.. make sure the amps are wired up with the largest wire that will fit in them.... also make sure you're using good ground areas.. the battery bank needs lots of grounds, with big wire.. Don't ever skimp in this area.. it will come back to bite you in the ***...

Finally... number 3.. you can't be a copycat in this game....

every box doesn't work in every vehicle... every box trick doesn't work in every box.. every woofer doesn't work the same in every box..

don't follow... use number 1 to make your own combinations come together.. That's one of the beauties of attending and competing at a world finals event.. you see all these completely different installs.. within tenth's of a db from each other... truly amazing..

leave yourself open to change, and be willing to spend countless hours working on your system... thats what it takes...

Loyd L.

Bumpin' Yota
07-07-2004, 01:54 PM
I agree with Loyd 110%.

BTW Im in sarasota, fl and have a termlab usb so if any one needs metering let me know.

kickerlivinloud
07-07-2004, 02:18 PM
Sorry, I had forgot that I needed to change my sig. I am looking at a HiFonics 1500D for now. Also I am getting the 15". I don't think I am giong to be able to get my hands on a mic anytime soon, if ever so that part will be hard. An HO alt and deep cell are also on my list for the future. I just want to get the basics right now and build from there. All this is going in a Buick Centery so I do have some limits on the size of my box. Space is no problem but hieght is. I am having to either put the face of the box at an angle or give the box an unregualar shape, hard to explain but I know what I am doing..lol. I am leaning more toward and angled face so I can move the box around a little. If I do it the other way it will be built perfectly to the trunk so I could not move it at all. I'm quite a ways away from FL or else I would take your offer up. Would be awesome to meet some of the ppl from here. Maybe one of these days I will.

Thanks everyone for your imput so far. Looking forward to getting the stuff in and start competing...


Jon

Randy Savage
07-07-2004, 02:20 PM
I should be attending a few shows in CT/NJ sometime this summer...I know it's a far ride for you, but may be something to do and experience...

Puggsley456
07-07-2004, 02:36 PM
ok guys heres one for ya! This weekend I'll be entering my FIRST competition. Now my box is tuned to 30 hz(Iknow its not the greatest fo spl). Now what frequencies should I start with for the comp? My hearing isnt that great so I really dont know where to start. Should I just use a 30 sec sine wave of a variety of freq. And I know you should base your tuning around the resonnant freq of the car but what should I do if I dont know it?

linksyz
07-07-2004, 08:41 PM
I'm still in my final planning stages for subs and amp but I thought I'd ask few questions before I go ahead and buy my equipment. First off, I have a 1999 Mazda 626 so I'm sort of limited when it comes to putting a big box in the trunk. I decided to go with 2 Treo SS15.44 and I'm going to power them both with Hifonics BX1500 (750wrms to each driver). Wayne from Treo told me that I would need 3.5ft^3 for both drivers sealed or 5.5ft^3 ported (I forgot to ask him what should I tune the box to). I'm probably gonna go with 2 1"MDF ported boxes (easier to fit them in). This setup would be used for daily driving, but I'd also like to compete at few small local car shows. I want my setup to be SQL for daily driving and maybe be able to have more SPL for competitions. I am going to run 1/0 awg wire, do the big 3, already have a quote from Iraggi for an 180 amp (better at idle than 200amp) alternator, and I'm still not sure what battery to get (right now i have Autocraft Titanium 800cca), but I'm prob gonna go with Optima Blue Top like Bumpin 'Yota recommended. So I have my electrical system pretty much covered up. I'm going to get about 40ft^3 of Dynamat Extreme and deaden the trunk. Would I have to use any other sound deadener that doesn't cost a lot along with Dynamat Extreme in order to reduce rattles? Where would you guys recommend facing the subs, what tuning should I have on the box, and how big of a port? Box is really concerning me right now, and I've posted on a lot of forums and haven't gotten any answers :(. Bumpin' 'Yota: I will come to dB Drag in Jupiter on August 14th and I won't have nothing installed by then, I hope I can see you there to ask you few questions :). Also, I've never built my box and I'll have to ask few local shops for quotes on it (Pro Sound.. shop in Gainsville quoted me $250 for those 2 boxes), or would you guys recommend that I get someone to do me a design so I do it myself? I know this is kind of OT (if you mods think its too much OT you can delete the post or I'll do it, and maybe have someone email me at [email protected] for few anwers)

Thanks,
Nino

Bumpin' Yota
07-07-2004, 08:48 PM
ok guys heres one for ya! This weekend I'll be entering my FIRST competition. Now my box is tuned to 30 hz(Iknow its not the greatest fo spl). Now what frequencies should I start with for the comp? My hearing isnt that great so I really dont know where to start. Should I just use a 30 sec sine wave of a variety of freq. And I know you should base your tuning around the resonnant freq of the car but what should I do if I dont know it?


Well ther are several ways to skin this cat. If I were in your shoes, and it was a dB drag event, id start out with a sine wave at 40hz moving up to 60hz for qualifying. (Keeping track of about when your car gets loudest.)

Then as soon as you can, pay for several reruns. (Inform the show promotor that you need to find your loudest note for these reruns - also keep in mind that the show promoter does NOT have to allow reruns after you qualify so in a multipointer it's unlikely you'll get reruns...)

Ideally you'd try to find your note while burping full tilt, but you do not have that luxury of time at an event. Therefore you will need to turn the system down about 20% from max and burp at each note starting at about 40hz and going up in frequency. Note what the score does. When the score stops climbing with each change of note you have a good idea of where your loudest note is.

Full power burping may or may not change this note, so in your elimination rounds you need to try refind the loudest note.

1. Right when the judges say "GO!" nail the system at the loudest low volume frequency for about 4 seconds straight.
2. Note the score. You'd be surprised how many times I've forgotten to do this - when in the lanes, there is a LOT of adrenaline.
3. Then, after you've noted the score, move down one frequency and make no other changes.
4. With about 5 seconds left, nail it again and see if the score changed.

If there was no change, the next time you run try one frequency higher than your loudest low power burp frequency.

If neither differing frequency improves your score you've found your loudest note.

If your score went up at all with either differing frequency, continue in that direction until your score stops climbing.


Once you have found your loudest note, THEN you can try changing other things like moving your seats, visors, center console, holding various panels etc.

but DO NOT make any more than 1 change at any one time!!! That way you know what each change does for your loudest volume. ;)

Puggsley456
07-07-2004, 09:00 PM
I heard somewhere that the loudest freq. is usually 10-15 hz above the port freq. If this is correct, which I dont know if it is, why would i have to go up to 60 hz?

Should I do a 40-50 30 sec wave that way I can sort of narrow the range down?

Bumpin' Yota
07-07-2004, 09:14 PM
I'm still in my final planning stages for subs and amp but I thought I'd ask few questions before I go ahead and buy my equipment. First off, I have a 1999 Mazda 626 so I'm sort of limited when it comes to putting a big box in the trunk. I decided to go with 2 Treo SS15.44 and I'm going to power them both with Hifonics BX1500 (750wrms to each driver). Wayne from Treo told me that I would need 3.5ft^3 for both drivers sealed or 5.5ft^3 ported (I forgot to ask him what should I tune the box to). I'm probably gonna go with 2 1"MDF ported boxes (easier to fit them in). This setup would be used for daily driving, but I'd also like to compete at few small local car shows. I want my setup to be SQL for daily driving and maybe be able to have more SPL for competitions. I am going to run 1/0 awg wire, do the big 3, already have a quote from Iraggi for an 180 amp (better at idle than 200amp) alternator, and I'm still not sure what battery to get (right now i have Autocraft Titanium 800cca), but I'm prob gonna go with Optima Blue Top like Bumpin 'Yota recommended. So I have my electrical system pretty much covered up. I'm going to get about 40ft^3 of Dynamat Extreme and deaden the trunk. Would I have to use any other sound deadener that doesn't cost a lot along with Dynamat Extreme in order to reduce rattles? Where would you guys recommend facing the subs, what tuning should I have on the box, and how big of a port? Box is really concerning me right now, and I've posted on a lot of forums and haven't gotten any answers :(. Bumpin' 'Yota: I will come to dB Drag in Jupiter on August 14th and I won't have nothing installed by then, I hope I can see you there to ask you few questions :). Also, I've never built my box and I'll have to ask few local shops for quotes on it (Pro Sound.. shop in Gainsville quoted me $250 for those 2 boxes), or would you guys recommend that I get someone to do me a design so I do it myself? I know this is kind of OT (if you mods think its too much OT you can delete the post or I'll do it, and maybe have someone email me at [email protected] for few anwers)

Thanks,
Nino

Pro Sound in Gainesville? I lived there for 4 years and never heard of that one....is it a brand new one on N Main street near the old AudioWorx? If that quote was for ported and finished boxes, it's a pretty good quote. I also build boxes for people as well, so lemme know....

I dont have a whole lot of time right now, so I'll post back later on tonight when I do. ;)

linksyz
07-08-2004, 12:23 AM
Pro Sound in Gainesville? I lived there for 4 years and never heard of that one....is it a brand new one on N Main street near the old AudioWorx? If that quote was for ported and finished boxes, it's a pretty good quote. I also build boxes for people as well, so lemme know....

I dont have a whole lot of time right now, so I'll post back later on tonight when I do. ;)

i'm not sure what the name of the shop was (I think he said somethin like Pro Sound and dudes name was Shane if I recall right). Yes, the quote he gave me was for ported boxes (he said he'd have to make 2 and put a board on top so it looks like 1 big box. Sarasota is a bit farther away than Gainsville (I'd travel up to Orlando or Gainsville to get my box). Thanks for replying, no hurry about posting, just do it when you get some free time :)

bigbassman
07-08-2004, 12:57 AM
ok guys heres one for ya! This weekend I'll be entering my FIRST competition. Now my box is tuned to 30 hz(Iknow its not the greatest fo spl). Now what frequencies should I start with for the comp? My hearing isnt that great so I really dont know where to start. Should I just use a 30 sec sine wave of a variety of freq. And I know you should base your tuning around the resonnant freq of the car but what should I do if I dont know it?

your peak will probably be in the 40-55hz area... best thing you could do is play say.. 40 hz.. then jump up to 45.. then 50.. and keep going until you don't gain on the meter.. then play around with frequencies between the tones you just played...

Loyd L.

Bumpin' Yota
07-08-2004, 01:27 AM
I heard somewhere that the loudest freq. is usually 10-15 hz above the port freq. If this is correct, which I dont know if it is, why would i have to go up to 60 hz?

Should I do a 40-50 30 sec wave that way I can sort of narrow the range down?


Ima get fired from my job due to lack of sleep posting on forums...lol

I've had systems that peaked about 4hz above their tuning to as much as 10hz. Same vehicle. Beats me why, but if I had to guess, I'd venture how the sub reacts to the box....

One lesson I learned early in my drag career, is that if you have NO idea what your note is, you shouldn't limit testing to what you think may be the loudest note. My old no wall install peaked at 38hz. Not at 42hz like I thought for a few shows. That mistake cost me 1.5dB or so... If you can test everything from 30-70, but I'd bet dollars to donuts your loudst is somewhere betweetn 40-60hz...

You'd probably be safe with 40-55hz, especially considering hte trunk car, but I have seen a few installs peak at 65hz. (CRX hatchback)

Randy Savage
07-08-2004, 01:33 AM
Hey Loyd, I think I recall reading something you said about switching your bracing...I'm throwing in some threaded rod tomorrow, what kind of gain did you see with the switch to threaded rod?

Bumpin' Yota
07-08-2004, 01:43 AM
I'm still in my final planning stages for subs and amp but I thought I'd ask few questions before I go ahead and buy my equipment. First off, I have a 1999 Mazda 626 so I'm sort of limited when it comes to putting a big box in the trunk. I decided to go with 2 Treo SS15.44 and I'm going to power them both with Hifonics BX1500 (750wrms to each driver). Wayne from Treo told me that I would need 3.5ft^3 for both drivers sealed or 5.5ft^3 ported (I forgot to ask him what should I tune the box to). I'm probably gonna go with 2 1"MDF ported boxes (easier to fit them in). This setup would be used for daily driving, but I'd also like to compete at few small local car shows. I want my setup to be SQL for daily driving and maybe be able to have more SPL for competitions. I am going to run 1/0 awg wire, do the big 3, already have a quote from Iraggi for an 180 amp (better at idle than 200amp) alternator, and I'm still not sure what battery to get (right now i have Autocraft Titanium 800cca), but I'm prob gonna go with Optima Blue Top like Bumpin 'Yota recommended. So I have my electrical system pretty much covered up. I'm going to get about 40ft^3 of Dynamat Extreme and deaden the trunk. Would I have to use any other sound deadener that doesn't cost a lot along with Dynamat Extreme in order to reduce rattles? Where would you guys recommend facing the subs, what tuning should I have on the box, and how big of a port? Box is really concerning me right now, and I've posted on a lot of forums and haven't gotten any answers :(. Bumpin' 'Yota: I will come to dB Drag in Jupiter on August 14th and I won't have nothing installed by then, I hope I can see you there to ask you few questions :). Also, I've never built my box and I'll have to ask few local shops for quotes on it (Pro Sound.. shop in Gainsville quoted me $250 for those 2 boxes), or would you guys recommend that I get someone to do me a design so I do it myself? I know this is kind of OT (if you mods think its too much OT you can delete the post or I'll do it, and maybe have someone email me at [email protected] for few anwers)

Thanks,
Nino

Not OT at all. ;)

Starting from the bottom up, to the best of my knowledge, adding dynamat knockoffs helped my score. (Using classic termpro, so I have no idea if I really did gain...) Most EVERYONE I talk to, tells me it hurt their scores a LOT. (Maybe I have a 153 on the TL right now and dont even know it! LOL) But it does WONDERS for rattles when used properly.

As far as firing direction and tuning, I don't know. That's something only a meter can tell you exactly. Your ears can do so to a degree, but often using one's ears is very misleading. (And damaging.)

Everything you mentioned looks good, and in fact I'd venture out on a limb and say you can likely support 2 1500s...(with 1 run of 1/0 for each amp because voltage drop between your battery and your amp is the DEVIL!!! lol)

One thing else - Ground your amp(s) with 1/0 not only to the floor boards, but also to the frame below. Then up front, do your big 3, but then upgrade and add grounds. You want the engine block grounded to the firewall, the frame, and the battery. Grounds are VERY important!

I have to make a trip to gainesville directly, so if you want we can get the ball rolling... PM me ;)

bigbassman
07-08-2004, 02:33 AM
Hey Loyd, I think I recall reading something you said about switching your bracing...I'm throwing in some threaded rod tomorrow, what kind of gain did you see with the switch to threaded rod?

well... going from a nasty wooden brace.. quite substantial gain...

in this last install.. I went from no interior bracing.. to horizontal allthread forward/back, and side/side.. yielded about 6 tenths...

Loyd L.

ramos
07-12-2004, 03:01 PM
yah.. I'll make it a point to visit this thread at least once a day...

and always keep in mind... every vehicle is different, every install is different.. what works in one car, may not in another.. thats the joy of competition SPL...

now ask away :)

Loyd L.



You guys are gods. :clap: I have been preaching this very same statement for years now. :clap: :clap: :)

kickerlivinloud
07-12-2004, 03:11 PM
Question, can bracing inside the box cause the box to sound different??? I remember reading somthing like that some were but I didn't know if it was true or not.


Thanks for all your help guys...


Jon

Bumpin' Yota
07-12-2004, 06:38 PM
Question, can bracing inside the box cause the box to sound different??? I remember reading somthing like that some were but I didn't know if it was true or not.


Thanks for all your help guys...


Jon

Yes, of course. If you have a very large box that is only a single layer, and without bracing flexes like mad, adding 3 layers to the sides (effectively bracing it) or adding all thread will stiffen the box.

Typically (not always, but usually) a flexing box will peak lower in frequency than a nonflexing one.

Now if that added bracing introduces resonances (like 2x4s do) you should be able to hear that.

I also believe, that the more you treat the air inside your box like a moving fluid instead of a gas, when designing your box, the better off you will be...

bigbassman
07-12-2004, 06:49 PM
Question, can bracing inside the box cause the box to sound different??? I remember reading somthing like that some were but I didn't know if it was true or not.


Thanks for all your help guys...


Jon

yup...

certain types of bracing (nasty wooden types) will cause turbulence and resonance..

same goes for thin 1 layer boxes.. nasty resonance above 60 hz....

also, a flexing box will yield a lower impedence, lower resonant point, and of course.. kills SPL :)

Loyd L.

bigbassman
07-12-2004, 06:50 PM
You guys are gods. :clap: I have been preaching this very same statement for years now. :clap: :clap: :)

you don't wanna play with me.... :(


we live 2 hours away... and I've yet to meet up with you...

wang

Loyd L.

Bumpin' Yota
07-12-2004, 07:46 PM
you don't wanna play with me.... :(


we live 2 hours away... and I've yet to meet up with you...

wang

Loyd L.


Who would wanna play with you? Didn't your mom had to tie a 64oz ribeye around your neck to get the family dog to play with you?

:D:D:D lol jk

ramos
07-13-2004, 08:41 AM
you don't wanna play with me.... :(


we live 2 hours away... and I've yet to meet up with you...

wang

Loyd L.



Jeez man, so does Rangerman but I haven't had that joy yet either :D One of these days brother man . I got to see the crazy eights :)

Puggsley456
07-16-2004, 08:03 PM
well guys, i hit 138.6 with the box 6inches from the rear of the trunck(to let my amp breath) facing towards the rear . I think my peak is arround 52hz but cant be certain until I get more meter time. Now my car doesnt have fold down rear seats. I can get them because they came factory as an option. How much do you think things will change if I fold em down?

TooLowTooGo
07-18-2004, 04:13 PM
ok question, now this isnt what can gain more db question...because i kno there are so many factors. this is more of a personal question.
which 2 boxes do you like better.

1. CRX style...wit subs up ports back

2. or subs and ports both facin back

i have a chevy blazer, and right now a crx box for spl comps. i just wanted to kno what everyone else thinks is more effective n like better.

bigbassman
07-18-2004, 06:45 PM
How much do you think things will change if I fold em down?

about 2-3.5 db

also gain .5 to 1.5 db for removing the rear deck speakers..

Loyd L.

bigbassman
07-18-2004, 06:47 PM
ok question, now this isnt what can gain more db question...because i kno there are so many factors. this is more of a personal question.
which 2 boxes do you like better.

1. CRX style...wit subs up ports back

2. or subs and ports both facin back

i have a chevy blazer, and right now a crx box for spl comps. i just wanted to kno what everyone else thinks is more effective n like better.

depends.. are you competing in dash legal SPL, or outlaw style..

one style does better legal, and another style works better outlaw.. :)

Loyd L.

TooLowTooGo
07-18-2004, 07:54 PM
last one i competed in was near the kicker panel. next one is on the 1st n thats goin by dash.
but no comps aroun here are illegal, all legal. so wich u think is better?

kickerlivinloud
07-20-2004, 04:16 PM
KK, new question. Should I brace my box on the outside or the inside??? I don't want my box to be huge so if I can save some air inside I am going to do it. Just cerious if that has any affect on the sound or anything....


Thanks...

Jon

saywhat?
07-20-2004, 05:09 PM
i know its not a crazy spl setup but im gunna be running 4 RE8's on a RF 500.2 (645 watts birthsheet) im gunna go 2 cubes obviously, its in a b2200, im not sure exactly on what i should port it at seeing that i want SQL out of these, i was thinking something like 35? if its allowed i can fold my passenge seast forward and my driver seat completely back to open paths for air, change visors, take out center console, all that stuff. im not sure what resonant freq. of the truck is, but i guess in logic a closed cab would be louder than a trunk? let me know what u think, and yota if u have AIM my name is sacreddispute03, i may want to use the mic some weekends, as im in orlando. u ever make trips around the state?

Puggsley456
07-20-2004, 07:47 PM
about 2-3.5 db

also gain .5 to 1.5 db for removing the rear deck speakers..

Loyd L.

Ok, Ive looked around and getting a different seat is totally out of the question. The work needed to track one down isnt something I wanna deal with right now. So, With the setup I have now would you recommend getting the most out of my system.
http://img51.photobucket.com/albums/v156/Puggsley456/Subs_and_box.jpg
^^^Heres where I currently have it because I need to let the fan on my PG amp breath.

http://img51.photobucket.com/albums/v156/Puggsley456/Ampinstall.jpg
^^^^Heres my amp which is installed on the back of the seat. Do you think it would be wise for me to take the seat right out and jump to another class?
Or just flip the box facing forward and seal it off?

packerfan
07-20-2004, 09:44 PM
What are some tricks for walls?

Bumpin' Yota
07-20-2004, 10:01 PM
What are some tricks for walls?

First measure everything. Realise you may have to actually build the box for the wall inside of the vehicle. If you have to do this, anchor what loyd calls a 'dance floor' The Dance Floor is just some MDF securely anchored to the floor of the vehicle, or where the floor of the box will be. It is on top of this dance floor where you will assemble the box for your wall. Having the dance floor inplace allows you to rotate and move the big box around easily to screw and glue everything together.

Typically, your box will be completely assembled save the face of it. (Double layer your box or triple it if you are worried about flex - recommended for anything over 10cubes.)

Once the 5 sides are together and dried, secure this box to the dance floor/car.

Since your box is 1.5-2.25" thick, you now have room to have an interchangable face, yet still keep that facia around the boxface to keep the rest of the car sealed off. You can use Lag Bolts to secure the face to the box. (Lag bolts are the very coarsely threaded bolts that screw into a lead sinker. The lead sinker is placed inside a hole and as the lag bolt screws into the sinker the sinker expands. You'll need 2.25" minimum for this to work.... 3" - 4.25" would be preferable)

For the facia around the face plate, I'd HIGHLY recommend buying a contour gauge so you can draw a line perfectly identicle to your interior. I'd also recommend carpeting the facia pieces unless you are after SPL only....

Make your port VERY sturdy and thick!! If the port is ~3" thick, you can place a 3" PVC 1/2 pipe at the end to reduce turbulence...

Remember the port is the point of TREMENDOUS acoustical pressure where spl will exceed 170dB.... 170dB at 40-50hz WILL shear drywall screws with EASE, so make sure the port is STURDY!

jbl_marshall21
07-21-2004, 07:48 PM
alright heres a good question, i think. i'm not sure how to say this but i'll give it a shot.

lately i have been trying out some tones and things w/o a mic. is there a point were turning the volume up so much would cause flexing on the vehicle, which would make it not be as loud as a lower volume, but by keeping the volume down, stop the flexing?

did u guys understand that? if not i'll try explaining it again

kickerlivinloud
07-22-2004, 12:16 AM
KK, new question. Should I brace my box on the outside or the inside??? I don't want my box to be huge so if I can save some air inside I am going to do it. Just cerious if that has any affect on the sound or anything....


Thanks...

Jon

Wow that is a good question! Now only if someone smart could help us out and give us an anwser...;);););););)



Jon

supa_c
07-22-2004, 12:24 AM
i have a Q. in my burb would it be better to fold down the 2nd row seats for more db. the box is facing the back with no carpet on the tailgate(fell off). maby put a sheet of mdf over the folded seats so the carped doesnt absorb the waves ? just wonderin.

TooLowTooGo
07-22-2004, 07:18 PM
ok i asked this in a thread aswell just incase. so if its not answered there maybe it will be answered here, i hope.

Distortion
ok Distortin, yes it is bad for a sub....real bad. buuuuut will distortion in SPL give u a higher DB?
what im saying is if u crank the volume n etc.... all the way up where u kno theres distortion, will it lessen ur db rating or higher it because its still louder?

supraman1379
08-02-2004, 09:58 PM
What should I do to make my sealed box louder, I already have polyfill in it.

jbl_marshall21
08-03-2004, 01:27 AM
port it, thats about the only way. or you can try firing it different directions.

supraman1379
08-03-2004, 10:18 PM
yea right now i have it firing on an angle up and towards the fron so it sounds pretty good. I also folded down the seat so it helps it a lot.

bigbassman
08-03-2004, 10:25 PM
alright heres a good question, i think. i'm not sure how to say this but i'll give it a shot.

lately i have been trying out some tones and things w/o a mic. is there a point were turning the volume up so much would cause flexing on the vehicle, which would make it not be as loud as a lower volume, but by keeping the volume down, stop the flexing?


nope..

Loyd L.

bigbassman
08-03-2004, 10:26 PM
KK, new question. Should I brace my box on the outside or the inside??? I don't want my box to be huge so if I can save some air inside I am going to do it. Just cerious if that has any affect on the sound or anything....


Thanks...

Jon

outside with wooden bracing

inside with all thread ONLY.. ever..

Loyd L.

bigbassman
08-03-2004, 10:27 PM
ok i asked this in a thread aswell just incase. so if its not answered there maybe it will be answered here, i hope.

Distortion
ok Distortin, yes it is bad for a sub....real bad. buuuuut will distortion in SPL give u a higher DB?
what im saying is if u crank the volume n etc.... all the way up where u kno theres distortion, will it lessen ur db rating or higher it because its still louder?

50% clip is the limit of gain in my testing..

never turn the headunit or gain all the way up...

set it properly

Loyd L.

bigbassman
08-03-2004, 10:28 PM
Do you think it would be wise for me to take the seat right out and jump to another class?
Or just flip the box facing forward and seal it off?

either way can work.. but without testing both methods.. I can't tell you which will do better in your install .. sorry

Loyd L.

ss3079
08-03-2004, 10:30 PM
Bracing the inside of a sealed fiberglass box ... any suggestions?

- Steve

bigbassman
08-03-2004, 10:30 PM
What are some tricks for walls?

extremely thick woofer baffles (depth of the woofer or more)

sand in between layers of MDF

lots of all thread bracing

corner slants in all 90 degree angles

resin in the box

rounding the entrance and exit of the port, or using PVC pipe over them

Loyd L.

bigbassman
08-03-2004, 10:31 PM
last one i competed in was near the kicker panel. next one is on the 1st n thats goin by dash.
but no comps aroun here are illegal, all legal. so wich u think is better?

CRX style

Loyd L.

bigbassman
08-03-2004, 10:32 PM
i have a Q. in my burb would it be better to fold down the 2nd row seats for more db. the box is facing the back with no carpet on the tailgate(fell off). maby put a sheet of mdf over the folded seats so the carped doesnt absorb the waves ? just wonderin.

yes, fold all the seats down you can... and fold the front seats forward

throwing a sheet of wood over the seats won't do much, if anything.. and will most likely disqualify you from most events

Loyd L.

bigbassman
08-03-2004, 10:34 PM
Bracing the inside of a sealed fiberglass box ... any suggestions?

- Steve

more fiberglass :D

or wood will do fine too

Loyd L.

bigbassman
08-03-2004, 10:35 PM
whew.. sorry took so long for me to reply :)

Loyd L.

ss3079
08-03-2004, 10:36 PM
more fiberglass :D

or wood will do fine too

Loyd L.

:D

It'll be thick, don't worry.

I'm glad to hear that I can use wood inside.

- Steve

bigbassman
08-03-2004, 10:40 PM
I'm glad to hear that I can use wood inside.

- Steve

yup.. alot of people (including yours truly) build a frame out of wood, and after several layers of glass are laid.. drill and screw down cross members inside.. then continue glassing.. to cover the screw holes :)

Loyd L.

ss3079
08-03-2004, 10:42 PM
I wouldn't have thought to do it that way ... good ... because I haven't done the front yet :D

- Steve

Puggsley456
08-04-2004, 02:03 AM
either way can work.. but without testing both methods.. I can't tell you which will do better in your install .. sorry

Loyd L.
I have now tried both set ups and i am havin trouble seeing a real difference. Maybe you guys can help I dont know why I didnt see more of an increase? With the seats up on the termlab mic I got a 138.6 but with the seats unbolted and folded down on the termlab sensor I only hit a 139.0

And because of the seats being unbolted i was in SS1-2. So next time my box is going on my back seat. Thats how the first place guy in my class had it! I wish I had known!

davesexplorer
08-16-2004, 12:46 PM
Hello....

I have a ford explorer and am testing a couple different boxes.....
currently I am building a "crx" box, 29x29x14, 4 4" aero's....

Do you think I could gain anything by smoothing the edges on the inside, maybe cutting some wood to make 45deg angles instead of 90deg's on the inside...?

Ricktc
08-16-2004, 08:34 PM
Hello....

I have a ford explorer and am testing a couple different boxes.....
currently I am building a "crx" box, 29x29x14, 4 4" aero's....

Do you think I could gain anything by smoothing the edges on the inside, maybe cutting some wood to make 45deg angles instead of 90deg's on the inside...?

Make it all 45's inside, reduces cancellation and air moves more freely through the port, make sure you put a piece of PVC on the back side of the box above the port on the top edge of the box, good for a 0.1 or 0.2 most of the time, if you don't know what I mean I will show you a picture.

-Rick

Acidburn
08-16-2004, 08:48 PM
Make it all 45's inside, reduces cancellation and air moves more freely through the port, make sure you put a piece of PVC on the back side of the box above the port on the top edge of the box, good for a 0.1 or 0.2 most of the time, if you don't know what I mean I will show you a picture.

-Rick
yes, please explain that last PVC thing

DBfan187
08-16-2004, 08:53 PM
yes, please explain that last PVC thing
Say the back end of your port is 4" wide. So you could cut some 4" PVC pipe in half and put it on the end to round it off instead of sanding, FB, ect...

Acidburn
08-16-2004, 08:55 PM
i still dont get it haha

DBfan187
08-16-2004, 09:00 PM
Like this.

http://memimage.cardomain.com/member_images/11/web/635000-635999/635350_53.jpg

See how it's used to round of the edge?

http://memimage.cardomain.com/member_images/11/web/635000-635999/635350_55.jpg

Acidburn
08-16-2004, 09:02 PM
so its basically like just using a router and rounding off the edges?

DBfan187
08-16-2004, 09:02 PM
Yeah............

Acidburn
08-16-2004, 09:04 PM
well you couldve just said that lol

im not sure thats what Rick was talking about though...

Ricktc
08-16-2004, 09:13 PM
Let me find a picture of a CRX box, and I will show you how to place it, it makes an easier transition for the air coming out of the ports/over the top of the box in turn making it louder...

-Rick

Ricktc
08-16-2004, 09:30 PM
OK, hope this picture works, now put the piece of PVC that is cut in half on the rear side of the box, on the top edge, above the ports. Hope that makes sense, my mad paint skills show it fairly well but on the REAR side of the box, above the aeroports.

-Rick

Acidburn
08-16-2004, 10:51 PM
hmmm... ok, i think i get it

davesexplorer
08-17-2004, 09:51 AM
Oh I've seen that many times before, and wondered what it was?? Thanks

KARLEON
08-22-2004, 11:39 PM
Ok, i have a question....I've asked it before but really didnt get alot of reply's or i keep getting mixed opinions, so now im putting together a survey type thing. And i get replys such as, try out each way and see which sounds better. That would be a great idea, but the enclosure im building is going to be so big imma have to build it inside my trunk. And i would have to completely destory that box and start all over again. I wish it was as easy as popping one in and popping it bacik out, but its not.

Anywayz, i have read on different forums that its BEST to fire the sub rearward. Im doing the best i can to use up all the cubes of airspace i can get, and in order for my to fire rearward i would be giving up airspace so i could have room to put the subs inside the box. So that really wasnt a plan at the top of my list, but if that would give me the best sound, i would look more into that option and do my best to make it work.

Next idea was to fire it into the cabin. Of course i would seal it off from my trunk, but i dont know exactly how it would sound. If this would be the best option or rearward. I also heard if i done this, i would have to change the polarity of the subs to make it sound best. Is this true or not? But the other day i measured and ran into a lil problem with this idea too. My clearance is about 32inches. Two 15in subs will be 30 inches and two sheets of 3/4 mdf on each side would be 1.5 inches. So it would be a TIGHT squeeze. And im not sure if i could get my port up under my 15s on the same plan or not. So that would make me have to port on the top of the box and have my ports extending up going through my 6x9 holes since i took them out. How would that affect the sound? Especially since i read it is best to have port and subs on the same plan.

And my last option was having everything in my trunk and firing my subs up. This idea runs into the least amount of problems, if any. Only thing im concerned about with this one is sound. I would have enough space to mount subs and also put my port on the same plan. I would dynamat my rear dash to make the rattles wouldnt be too insane. But i have heard firing subs upwards isnt the best of ideas due to the flow of sound waves, etc....

Again, the enclosure im planning on is going to be huge and i just cant test it out to see. Thats why i would like to see everyone respond who has saw alot of different set ups that sounded very well and loud. Oh while im at it, is there a special rule to go by when trying to figure out how much port area to give your subs?

By the way, my car is a 96 Honda Accord. Sub planning on running is two 15" DP in a 7-8 cubic foot enclosure. Each sub will roughly see 900-1200W RMS each. And yes my back seats do let down.

davesexplorer
08-23-2004, 10:23 AM
Sorry to interrupt, but thank you very much for the help, I'm now up to a 148.5 certified in street B.... I have some more tricks to try though!

delvryboy
09-02-2004, 06:15 AM
mmmm....lots of good info.

one thing that wasn't mentioned....

don't be afraid to start over, don't get discouraged if your numbers aren't where you want them first time out. sometimes you have to reach your goals one tenth at a time. i am at the point where i am planning my next rebuild during my current build. every build yeilds better results and you learn from your errors and your success. remember, there is no 'perfect recipe' for an SPL rig, it's all trial and error(of course you can avoid some of this by following suggestions ;) )


PS - axe, hammer, torch, and welder are your friends

KARLEON
09-02-2004, 12:59 PM
No body feels like tackling my questions above?

delvryboy
09-02-2004, 03:15 PM
No body feels like tackling my questions above?
rearward is good for all around daily driving, it will more than likely sound a little louder and deeper this way.....it's not always the loudest on the mic though. the bigger your box, the more tight the trunk fit is, the more your #'s will go down when firing rearward.

firing toward the trunklid is a big NO. not only will you lose output to the ear, the mic will laugh also.

forward firing seems to be the best for spl, at least in my experience. best would be port on the drivers side, subs next to each other. if you can't squeeze it like that, port along the bottom will suffice. make sure when you seal it, include the rear deck, a lot of people overlook this. i've founf just a few small holes in the rear deck can lower spl. some more benifits to forward firing is you have more usable trunk space and you don't have that annoying trunk rattle.

KARLEON
09-02-2004, 04:12 PM
Thanks alot for replying..I was starting to think no one had the answers..

Let me ask u something about firing my subs inside the cabin...Ok its going to be a really tight squeeze to fit my two 15s in that small opening....its about 33inches in length. two 15s will take up 30. Anywayz, i definately wont have enough room to port on the drivers side.... If i have enough room to port on the bottom below my subs, i will do that....But lets just say i wont have enough room.....How about sealing off my rear deck but leaving holes for my port...So everything is sealed off, and my ports are on the top of my box being fired into the cabin from the top...Do any of you know how that will sound?

kickerlivinloud
09-02-2004, 04:17 PM
rearward is good for all around daily driving, it will more than likely sound a little louder and deeper this way.....it's not always the loudest on the mic though. the bigger your box, the more tight the trunk fit is, the more your #'s will go down when firing rearward.

firing toward the trunklid is a big NO. not only will you lose output to the ear, the mic will laugh also.

forward firing seems to be the best for spl, at least in my experience. best would be port on the drivers side, subs next to each other. if you can't squeeze it like that, port along the bottom will suffice. make sure when you seal it, include the rear deck, a lot of people overlook this. i've founf just a few small holes in the rear deck can lower spl. some more benifits to forward firing is you have more usable trunk space and you don't have that annoying trunk rattle.

Not always true. In your car it may work but in the next car you may get the opposite effect. There is no real "best position" for a sub. It is all dependent on the car/vehical. Ones best bet is the try every position and wait untill they find the position which best pleases them....


Hope this helps a little....



Jon

ss3079
09-02-2004, 05:28 PM
vehical

That some kind of chilli? :fart: ;)

He also said he's building the enclosure inside of his trunk, so there's no way he'd be able to try different firing positions :)

You're right when you said the best way is to try different positions, but it's just not possible in this case.

Next best thing to do would be to find someone with the same vehicle and see what they think, I guess ...

- Steve

kickerlivinloud
09-02-2004, 05:41 PM
Sorry Steve I have terrible spelling as I'm sure you have seen by now ;)



Jon

ss3079
09-02-2004, 05:50 PM
Sorry Steve I have terrible spelling as I'm sure you have seen by now ;)



Jon

Hehe, was just kidding around :D

Order the DP ??

- Steve

kickerlivinloud
09-02-2004, 05:52 PM
Very soon, money is finally coming in. I should be ordering it by or before the 20th of this month...




Jon

Breakdancin11
09-22-2004, 03:21 AM
I have a 93 Cadillac Deville with a 15 RE XXX in a 5.2cuft box ported at 32hz for daily and I am going to be making a port plug for 46hz-48hz not sure what at the moment. Now the trunk of the caddy is sealed like a **** tank so I was wondering if I took out the rear fill speakers if that would make a port to the inside of the caddy and possibly make it louder inside.

Also at the moment the only thing I have right now is the XXX with a Cadence ZRS-9 powering it. As well as some Eclipse aftermarket speakers. Would adding some comps, or a Audiocontrol Epic 150, or possibly a Higher End Head Unit ( I have a low end Clarion at the moment ) help with a higher SPL?

-Jp

delvryboy
09-22-2004, 03:24 AM
remove the rear seat. the bottom unlatches. remove the headrest, remove 2 nuts at the bottom of the seat back. you will see an indentation in the sheet metal, using a sawzall, cut it out. does wonders ;)

http://memimage.cardomain.net/member_images/9/web/381000-381999/381419_65_full.jpg

Breakdancin11
09-22-2004, 05:00 AM
:eek:

That almost brings tears to my eyes. I love my bumps but I dont think I could ever do that to my Caddy heh. Did you ever put the Caddy to a meter with the seat/wall o metal intact? Any other suggestions?

-Jp

delvryboy
09-22-2004, 12:53 PM
it's about a 3-4db difference with the metal out. i love my caddy too, but with all of the interior and trunk panels in place, you'll never notice it missing.

also, that hole is extreme. i cut more out and fire forward. if you remove the seat, you'll see the area i was originally talking about. thats more than enough.

Ricktc
09-22-2004, 02:49 PM
Taking the rear speakers out will yeild a small gain also.

-Rick

delvryboy
09-22-2004, 02:57 PM
Taking the rear speakers out will yeild a small gain also.

-Rick
about .5 db in the caddy

Ricktc
09-22-2004, 06:13 PM
I am not sure if it made any difference in my car because the seats fold down flat, but they sure did make a difference when the seats are up...

-Rick

Breakdancin11
09-23-2004, 02:58 AM
What if I took out the rear fill speakers then cut out some ports on the same plane of the rear fill speakers?

-Jp

delvryboy
09-23-2004, 03:25 AM
What if I took out the rear fill speakers then cut out some ports on the same plane of the rear fill speakers?

-Jp
you could remove the rear glove box and cut the sheet metal out underneath it, then attach the lid with velcro if you want to cover it up. still not the same as the sheet metal ;)

Breakdancin11
09-23-2004, 04:16 AM
you could remove the rear glove box and cut the sheet metal out underneath it, then attach the lid with velcro if you want to cover it up. still not the same as the sheet metal ;)


:laugh:

Thats exactly what I was thinking. Now if I were to do this would I be gaining more then just a .5 decible? What about cutting a hole where the armrest is?

If the sub is rear firing will this cause any problems or will I have to switch the way they are firing? Also, will their be a good increase in the bass to the human ears if I were to do some cutting, seeing as thats what I really want.

-Jp

delvryboy
09-23-2004, 12:34 PM
:laugh:

Thats exactly what I was thinking. Now if I were to do this would I be gaining more then just a .5 decible? What about cutting a hole where the armrest is?

If the sub is rear firing will this cause any problems or will I have to switch the way they are firing? Also, will their be a good increase in the bass to the human ears if I were to do some cutting, seeing as thats what I really want.

-Jp
alot of bass to the human ear :D if your gonna cut behind the armrest, you might as well remove that whole section...take your seat out and you will see what i am talking about. then you remove that plastic panel behind the armrest and keep it folded down...difference is night and day.

Breakdancin11
09-23-2004, 07:06 PM
alot of bass to the human ear :D if your gonna cut behind the armrest, you might as well remove that whole section...take your seat out and you will see what i am talking about. then you remove that plastic panel behind the armrest and keep it folded down...difference is night and day.

Ok so if I were to take out the rear speakers AND cut the piece out of the back of the Caddy it will be louder then maybe just taking out the rear speakers. You have me almost talked into taking out that panel. You said that I may as well take out the rest of the panel if I were going to cut for the armrest. So there would be a difference from a small hole cut and the armrest down and a big hole cut with the armrest down. Also how big is the piece you would have to cut for this big cut......the picture you should me was HUGE.

I appreciate all the help your swinging my way

-Jp

delvryboy
09-24-2004, 03:20 AM
Ok so if I were to take out the rear speakers AND cut the piece out of the back of the Caddy it will be louder then maybe just taking out the rear speakers. You have me almost talked into taking out that panel. You said that I may as well take out the rest of the panel if I were going to cut for the armrest. So there would be a difference from a small hole cut and the armrest down and a big hole cut with the armrest down. Also how big is the piece you would have to cut for this big cut......the picture you should me was HUGE.

I appreciate all the help your swinging my way

-Jp
i took alot of material out, you don't have to remove that much. if you remove the seat, you'll see an indentation, you can't miss it. probably about 15"x30"

delvryboy
09-24-2004, 03:28 AM
this is ugly, but it's the loudest way to set it up for the meter. you do have some slight low end loss, but you also lose all trunk rattleing. with the seat and panals back in place, you can't see the messy stuff.....you would also have to remove the trunk lid springs, it's not for everyone ;)

http://memimage.cardomain.net/member_images/9/web/381000-381999/381419_62_full.jpg

http://memimage.cardomain.net/member_images/9/web/381000-381999/381419_66_full.jpg

http://memimage.cardomain.net/member_images/9/web/381000-381999/381419_69_full.jpg

http://memimage.cardomain.net/member_images/9/web/381000-381999/381419_68_full.jpg



here's rear firing

http://memimage.cardomain.net/member_images/9/web/381000-381999/381419_72_full.jpg

Breakdancin11
09-24-2004, 03:54 AM
I am to do some cutting and see if I am satisfied with just cutting out the spot where the armrest goes as well as removing the rear speakers. Maybe this will cure my need for more bass for the time being heh. Any problems I may run into while cutting the spot for the armrest?

-Jp

delvryboy
09-24-2004, 03:57 AM
I am to do some cutting and see if I am satisfied with just cutting out the spot where the armrest goes as well as removing the rear speakers. Maybe this will cure my need for more bass for the time being heh. Any problems I may run into while cutting the spot for the armrest?

-Jp
nah. when you remove the seat, the armrest will come with it. just take the plastic insert out. then drill a hole in the sheet metal and cut out your desired area with a jig saw or sawzall.

Breakdancin11
12-09-2004, 01:52 PM
I was looking at your Caddy on Sounddomain and seen that you glassed the sub box to the back of the cut through which would seal the sub into the cabin.

What all is involved with the glassing process?
I have never glassed anything would I be better off getting a shop to glass that part?
Also if I were to do the cut through without glassing for alittle would I still be able to hear a noticable difference in how loud it will get?

-Jp

193dBman
02-01-2005, 10:22 AM
Howdy, this is off topic i think? But is it a necessity to port a box for spl. I'm nervous about it cause my spl setup is gunna be in my daily driver and i dont want sick nasty port noise or loss of low end. Thnx.

Ricktc
02-01-2005, 05:19 PM
Yes porting is a necessity. Port it, but tune it low, will still sound awesome, get low, put up better numbers and sound louder than sealed.

-Rick

profoundwill
02-11-2005, 03:25 PM
Does anyone know any tricks to gain higher SPL in a 2002 gmc Sierra extended cab? Also, anyone have a SPL meter close to Birmingham, AL?

amermuscle15
03-12-2005, 05:30 PM
Does anybody have any experience with smaller cars? I have a 95 grand am (2door) and was thinking of facing the box forward for competitions. Now would I be better off pushing the box right up against the rear seat area or pushing it towards the rear but the sub still facing the front? The rear speakers were removed by the way...

Abel
03-12-2005, 05:38 PM
Does anybody have any experience with smaller cars? I have a 95 grand am (2door) and was thinking of facing the box forward for competitions. Now would I be better off pushing the box right up against the rear seat area or pushing it towards the rear but the sub still facing the front? The rear speakers were removed by the way...


I am running 2 15's in a Kia Rio and have found that it is louder for my car to still face them towards the trunk,my answer for you would be to just play around with them and see what works best for you

amermuscle15
03-12-2005, 07:30 PM
Ya im gonna but was just curious what others have done..

davesexplorer
03-12-2005, 07:53 PM
my old cav, I sealed off from the trunk, port and subs faced forward.

smkmotorsports
03-24-2005, 01:42 AM
i've got a question i just entered my first show March 12th here in Columbus, Ohio, very PISSED off about the outcome. I have 4 audiobahn 1200q's and i hit 139.2 dB's on the get go and never went up on the meter. i'm having a custom box built and upgrading my 8gauge wire to a 0/4 gauge wiring kit and also bought a Mmats 2000 watt amp. i'm looking to try to get 152+ dB's what else can i got to reach my goal?


Thanks,
Rob

nikosbuddy
03-24-2005, 01:49 AM
So when a sub is on...and playing, sounding great...then you try and turn up the sub output on your head unit...it sounds good till you start getting higher up....and it starts making that durr....durr noise when it hits hard...what is that...With the power your giving a subwoofer, and its playing...with more wattage what does that do...and also if you add the wattage, what does it affect, i understand it makes it louder...and hit harder...well thats if the sub can take it but presumably if you do give it more power is it likely to make the noise or is it going to get deeper and not affect it, my sub can take a clean 2500 watts easily and i have every intention of giving it to him but what im worried about is the durr noise it only happens at certain levels and you know what it sounds like everyone does...whats it saying my headunit is crapping out my amp is crapping out and needs more power or what? just a couple questions for all you knowledgeable people out there...i would really apprecaite it because i know my sub has the potential easily...most definetly...i just want to sound good in the process, because my seats are down and when im not trying to overpower it/ do what ever im doing to it...it sounds amazing..can someone anyone help this is Aka Noob/ A little Fyi because i knwo everyone has asked this question at one point in time....
im getting it metered to...
Mike

TooLowTooGo
03-24-2005, 02:32 AM
i've got a question i just entered my first show March 12th here in Columbus, Ohio, very PISSED off about the outcome. I have 4 audiobahn 1200q's and i hit 139.2 dB's on the get go and never went up on the meter. i'm having a custom box built and upgrading my 8gauge wire to a 0/4 gauge wiring kit and also bought a Mmats 2000 watt amp. i'm looking to try to get 152+ dB's what else can i got to reach my goal?


Thanks,
Rob

its all in the install

2000watts and a 152db goal... all in the install

i hit a 152.2 n 152.5 on the new audiocontrol..aroun a 149or so on the new TL
to reach this goal i had 2/0 wire from my bat straight to the amps
1/0 wiring for the big 3
2 straped power acoustik A3000DB's on 4 12" MTX 7500's in a SPL designed box CRX style tuned to 48hz

so like i said for u to get that 152...its all in the install n box positioning designing etc...

just dont get down after ur first event,, the first time i competed i hit a 141. now im at 150's. just try new things..remember 70%install 30%products

smkmotorsports
03-24-2005, 02:40 AM
ok word. what kinda box should i use sloted port or sealed? and should i fire them straight up or fire them to the back? It's in a 2000 Ford Expedition

smkmotorsports
03-24-2005, 02:41 AM
and i'm competing in the Modified Class 3

Ricktc
03-24-2005, 11:16 AM
PORTED! CRX style box would likely be your best bet. Check out www.termpro.com and look in some of the galleries/forums and you might find some pictures of street SUVs.

-Rick

req
03-24-2005, 11:48 AM
ok word. what kinda box should i use sloted port or sealed? and should i fire them straight up or fire them to the back? It's in a 2000 Ford Expedition

http://forums.caraudio.com/vb/image.php?u=14202&dateline=1092859886

like that would be quite nice. LOL - its the CRX box that he made and is telling you to make(above)

you will ONLY want ported. sealed is for SQ and it wont get NEAR 150's the way you are talking.

lots of pore cross sectional area, high tune (5~10hz below resonant frequency of the car) and correct placement = teh score.

just a few tips ive seen around. but again, im no spl guy (i soon will know a bit more) so i dunno.

TooLowTooGo
03-24-2005, 12:41 PM
http://forums.caraudio.com/vb/image.php?u=14202&dateline=1092859886

like that would be quite nice. LOL - its the CRX box that he made and is telling you to make(above)

thats not a CRX style box..thats my daily driving box
http://www.caraudio.com/vg/showimage.php?i=4481&catid=searchresults&searchid=1217
those are my SPL boxes..CRX style
CRX - Subs facing up, Port facing toward the back end of the car

dont do a sealed..ported is aroun a 3db increase from sealed
if u want to just make 1 box and still compete id suggest a tuning of aroun 35hz...SQL, daily for SQ n still can peak for SPL

req
03-24-2005, 01:30 PM
thats not a CRX style box..thats my daily driving box
http://www.caraudio.com/vg/showimage.php?i=4481&catid=searchresults&searchid=1217
those are my SPL boxes..CRX style
CRX - Subs facing up, Port facing toward the back end of the car

dont do a sealed..ported is aroun a 3db increase from sealed
if u want to just make 1 box and still compete id suggest a tuning of aroun 35hz...SQL, daily for SQ n still can peak for SPL

whoops :)

i thought it had a small port size. but like i said, im not SPL. i figured that was your box :p:

i stand corrected. :up2somet:

WheresTheButta
05-09-2005, 02:57 PM
this thread has been really helpful.
I'm now more confused than ever with my future setup possibilities..... this opened up a whole new range of ideas for me. I never even thought about TRYING to fire the sub into the cabin.

WheresTheButta
05-09-2005, 03:11 PM
maybe I'm dumb for asking this......
but my friend showed me a link a lonnnnng time ago of some guy using crazy physics formulas to create sound out of tiny explosions..... his tweeters hit 170db and shot like 8 inch flames... and apparently are incapable of distortion.
can that be used in a car? get like 30 of those set up in a fireproof car and hit 9999999db?

Raven
08-02-2005, 11:08 PM
Thanks to how thin this planet's atmosphere is, 180 is right about the physical limit of SPL production. Anything significantly higher than 180 (181,182,183) could be done underwater. But to answer that one, no. Plus I don't think anyone within audible range of you would think highly of you for going for an SPL record at 12,000hz. ;)

I have a question of my own. Not entirely related, not entirely off topic. Are there official frequency ranges for subbass, midbass, midrange, and highs? I've always thought it was just two octaves up starting at 20hz. (20-80 subbass, 80-320 midbass, 320-1280 midrange, 1280 up highs)

nissanrider06
09-13-2005, 10:00 PM
hey, whats the optimum port to box ratio, and in ppl's experience do short wide sorts work better? or long skinny ports???

nissanrider06
09-14-2005, 07:01 PM
checkin this forum everyday huh?

whats the optimum port to box ratio, and in ppl's experience do short wide sorts work better? or long skinny ports???

bimma85
06-09-2006, 02:51 AM
What the hell ever happened to this thread? :(
No time or money to do anything this year, but will hopefully have a tl and some more equipment/tools by the end of the year :D.
Before I had asked what kind of vehicle to get and I was told it depends on the organization. How do I know what vehicle will be good for what organization? :confused: vehicle will most likely be an extened cab tacoma. Looking to get into dbrag, because it seems thats all there is in iowa.

SPL140.2
06-09-2006, 02:55 AM
cant go wrong with a crx in any organization, thats like the most popular vehicle you see at major events :(

bimma85
06-09-2006, 02:57 AM
cant go wrong with a crx in any organization
I already have a tacoma and doubt I'll have the funds for a different ride. If so, I'd prolly just keep my s10 blazer, but need some $....so its up for sale

bimma85
06-10-2006, 11:13 PM
What the hell ever happened to this thread? :(
No time or money to do anything this year, but will hopefully have a tl and some more equipment/tools by the end of the year :D.
Before I had asked what kind of vehicle to get and I was told it depends on the organization. How do I know what vehicle will be good for what organization? :confused: vehicle will most likely be an extened cab tacoma. Looking to get into dbrag, because it seems thats all there is in iowa.
^^^

bimma85
06-14-2006, 03:28 AM
^^^
:crap:

snb778
06-14-2006, 03:32 AM
ok ok, so how do you get a higher drive by score...what things do you have to change to obtain this?

bimma85
06-15-2006, 09:44 PM
What the hell ever happened to this thread? :(
No time or money to do anything this year, but will hopefully have a tl and some more equipment/tools by the end of the year :D.
Before I had asked what kind of vehicle to get and I was told it depends on the organization. How do I know what vehicle will be good for what organization? :confused: vehicle will most likely be an extened cab tacoma. Looking to get into dbrag, because it seems thats all there is in iowa.
:(

Megalomaniac
06-18-2006, 10:12 PM
I have a 4cube box(after displacement) for my SX. I got metered yesterday,i got a 139.3. Im sure i can get a 140 had i fired the sub to the side. but will a 3.5cube box change my results in my favor. I figured 4cubes would give me more output. i want get better numbers. What if i make a box that is a little bit bigger?

bigbassman
07-14-2006, 10:44 AM
ok ok, so how do you get a higher drive by score...what things do you have to change to obtain this?

first off, the vehicle is the most important..

you need something with large windows, that are reletively square..

then you need a low tuning... and the right song

Loyd L.

davesexplorer
07-14-2006, 04:29 PM
What the hell ever happened to this thread? :(
No time or money to do anything this year, but will hopefully have a tl and some more equipment/tools by the end of the year :D.
Before I had asked what kind of vehicle to get and I was told it depends on the organization. How do I know what vehicle will be good for what organization? :confused: vehicle will most likely be an extened cab tacoma. Looking to get into dbrag, because it seems thats all there is in iowa.

I'm no expert... but... in dbdrag at least I noticed that the loudest folks had or the easiest vehicles to get loud -

for Street Classes go for a CRX, 4 door Explorer 95-01(NOT A 2DR I found that out the hard way :( ) or if you can find one a Panda or something small. A Jeep Wrangler made it up there a lil while back too.

Super Street NW/W Classes, as above with the addition of Caravan's, Astro's, Big Old Ford Vans, SUV's, Vans or pickups with cutthrough's/blowthroughs.

davesexplorer
07-14-2006, 04:31 PM
I have a 4cube box(after displacement) for my SX. I got metered yesterday,i got a 139.3. Im sure i can get a 140 had i fired the sub to the side. but will a 3.5cube box change my results in my favor. I figured 4cubes would give me more output. i want get better numbers. What if i make a box that is a little bit bigger?

Find out what your vehicle likes then exploit that frequency.. tune a lil below so your peak is where you want it to be.

snoopdan
07-14-2006, 04:38 PM
If you look what's dominating MECA right now, you cannot win in MECA street class without a CRX...PERIOD.

These are the vehciles with the highest scores in MECA's street class right now

Current highest SPL Sreet Scores

CLASS NAME VEHICLE
-----------------------------------------------
Street 1 : Joeseph Ault, Sr. -- CRX
Street 2 : Dan Bates -- CRX
Street 3 : Jack Thomas -- CRX
Street 4 : Terry Shores -- CRX
Street 5 : Eric Balmert -- CRX

at least im in 2nd with a my Jeep in street 3 :(

so if your wanting to compete in MECA, buy a CRX

Megalomaniac
07-14-2006, 07:52 PM
Find out what your vehicle likes then exploit that frequency.. tune a lil below so your peak is where you want it to be.

How do i know what my car likes, is there a certain process to achieve this. and also I know most people who do SPL tune high. but i am curious I would like to attempt now to go for the lower notes like 28hz or better yet go for more SQl I don't know man, It feels like puberty again,so many things i would like to do but i don't know what to do.

snb778
07-14-2006, 08:00 PM
Ive got 2 questions.....

1. How do you compete in AS with a hatchback....isnt the window line usually within a foot of the bottom of the hatch??..especially the hatch window??

2. How do you improve your driveby score. Because ive noticed that cars with less SPL inside the car can get a higher drive by score than a car with a higher SPL inside the car....?? is this just all car dependant???

davesexplorer
07-15-2006, 12:24 PM
How do i know what my car likes, is there a certain process to achieve this. and also I know most people who do SPL tune high. but i am curious I would like to attempt now to go for the lower notes like 28hz or better yet go for more SQl I don't know man, It feels like puberty again,so many things i would like to do but i don't know what to do.

What some ppl say works for the resonant/peak freq (besides other ppl experiences) is using a general sealed enclosure with a sub, playing a frequency sweep and reading the results, taking into consideration things like the sub/box peak, seats folded, console open, things laying around etc. You can get really nitty gritty, but most people that really want pure spl test, then test, then test again, and again and again.. kinda turns into a job I guess? I never got that into it though. Once you filter out all the other junk, you'll end up getting a frequency that your car "likes", my 2dr exploder for example likes around 48 hz.. dont know why but it does, a 4 door on the other hand would be better of with 50-53hz. The way I understand it this is where all the things in the car, on the car, and the car itself are moving in unison at or around this frequency and creating additional support for the speakers playing the tone. (correct me if I'm wrong)

You can look at response graphs for more explanation, get your vehicle on a termlab and you'll see. Take any normal vehicle, play a tone and not only will you see the big hump where your tone is but you'll probably see a bunch of other humps too. If you take an extreme vehicle in the same way, those little humps will all but dissappear - in an extreme veh. you are essentially making the interior burp friendly...

Tuned high ***** for daily period. I hated when I had my high hz boxes in my truck. If you want daily tune lower and sacrifice the numbers.. that's what I did. (although not besting 150 pi$$ed me off) Or just live with *** sounding bass and tune high. Sorry so long... Others can probably chime in better than I can anywhoo.

1loudsuv
07-15-2006, 12:49 PM
I'm no expert... but... in dbdrag at least I noticed that the loudest folks had or the easiest vehicles to get loud -

for Street Classes go for a CRX, 4 door Explorer 95-01(NOT A 2DR I found that out the hard way :( ) or if you can find one a Panda or something small. A Jeep Wrangler made it up there a lil while back too.

Super Street NW/W Classes, as above with the addition of Caravan's, Astro's, Big Old Ford Vans, SUV's, Vans or pickups with cutthrough's/blowthroughs.
2 doors can get as loud as the 4 doors. theirs a couple of things i dont know if you tried but if you want to know go ahead and ask. i know i can get you to at least a 150.9 in street b but depending on eqiupment....

i switched to street a i was doing a mid 151 with one sub that was rubbing an old 2150 wich didnt have much life left in it. and amps at 1.5 ohms strapped

im running the amps at .7 strapped and put an nsb 90 (i was dropping to 8.5 with the 2150 now im dropping to 10.0 volts) and ive added angles inside the box and alot of ductape....

i really dont know what score im doing could be 149 could be 154 who knows till i put it on the mic but i might not i might just hit tommorows without any testing...

so ask any questions you want

davesexplorer
07-16-2006, 02:48 AM
Yeah let me know anything you'd like to divulge... keep the rest I dont need to know all your secrets. :)

My equipment so far is a Kinetik Monster, Solo X 12" (When it finally comes) and a Hifonics Goliath amp. Eventually I'll get another solo, but that probably wont be till next season.

My hurdle in the sport has been the lower frequency peak, I literally switched my old crx box, w/ two dd 9512's and two orion 2500D's to a four door and went from a 148.9 to a 151.x... on a termlab. (From a 48hz in my truck, to a 51 in a friends) Given it wasn't a fart box, but still.... I'm not goin nuts this season, maybe a show or two. Thanks.

TooLowTooGo
07-16-2006, 02:52 AM
a 4 door on the other hand would be better of with 50-53hz.

not all. my 4 door is the same as ur 2door. it likes 48hz.
It doesnt matter even if the box is tuned to 55hz. once i hit that 48hz tone, the db's will go up. very strange.

1loudsuv
07-16-2006, 09:34 PM
Yeah let me know anything you'd like to divulge... keep the rest I dont need to know all your secrets. :)

My equipment so far is a Kinetik Monster, Solo X 12" (When it finally comes) and a Hifonics Goliath amp. Eventually I'll get another solo, but that probably wont be till next season.

My hurdle in the sport has been the lower frequency peak, I literally switched my old crx box, w/ two dd 9512's and two orion 2500D's to a four door and went from a 148.9 to a 151.x... on a termlab. (From a 48hz in my truck, to a 51 in a friends) Given it wasn't a fart box, but still.... I'm not goin nuts this season, maybe a show or two. Thanks.
empty your pm box some good info going your way i see a 152-53 coming out of you if you listing :)

TooLowTooGo
07-17-2006, 12:43 AM
my pm box is clear if u wanna send em to me 2 :)

954runner
07-17-2006, 12:49 AM
ok i guess ill n00bx it up a bit...
my old sub-stage consisted of a 15" Diamond D9 off a JBL bp600.1 in a 4.5 cubic foot box, tuned to about 25 Hz. when i had it metered, i had a 137.9 db, which i was not pleased with at all.
so, i built a new box. same sub, this box is 3.5 cubic feet, tuned to 37 Hz. also, i'm replacing the JBL with a hifonics bx1500d (1000 watts @ 2 ohms). do you think i will see a 140 on the screen this time? the hifonics is rated at 14 volts, and i know i can't sustain 14 volts on a consistent basis (probably more like 13) so will i see about 800 watts or so?

davesexplorer
08-10-2006, 02:09 PM
empty your pm box some good info going your way i see a 152-53 coming out of you if you listing :)

I listened... and built :)

Not metered yet, it may never be as I got a good deal on a second SOLOX :yumyum: so I'll have to redo everything again.

http://memimage.cardomain.net/member_images/8/web/728000-728999/728977_115.jpg

Has 3- 4" aero's toward the back, box is 3.7 b4 disc. It does get hella loud and pretty low!

xtremebassjunky
08-14-2006, 05:24 AM
out of curiousity what do you guys think of me using a 2005 toyota highlander for a daily/spl vehicle.... right now I have a 96 Jimmy 4dr and have a single 15" L7 to hold me over for now...
http://i56.photobucket.com/albums/g171/xtremebassjunky/100_0479.jpg

anyways the real question is what do you think of 2 Z2 amps both running @ 1 ohm pushing 4 9512s...basically it will be a 16000w system...what kind of #'s are possible? I have some help for the project when it starts this spring from a buddy of mine (Brian B.) but I was still interested on your feedback... OBVIOUSLY major electrical upgrades, but I thought this would make for a very good setup for Street Beat 3 and for the daily...:yumyum:

aaron7114
09-11-2006, 08:30 PM
I have a 94 accord with two 15 inch L5s with a Hifonics BX1605D (1600 RMS). Right they they are in two sealed boxes but I am planning on porting them this weekend. I want to port them this weekend because there is a competition I am wanting to go to the following weekend.

Ive heard that CRX style (subs facing up, ports facing the back of the car) gets the loudest. However how well does that sound? I dont see how it could sound all that good with the sub facing up towards the trunk. I really dont see how it would get loud either.

I really wont be entering that many comps, just when they have them in jonesboro (20 miles north of me)...so I would like it to sound fairly good as well.

So do you think it would be better to do the CRX style or subs facing towards the back or towards the front? Please post all your suggestions.

Fosgate-Kid
02-26-2007, 11:47 PM
What are some ways to squeeze more spl out of a sealed truck box?

ThomasG
06-11-2007, 02:53 PM
Ok i have a competition on the 16th. And dont know what class im in. And its a outlaw + streetbeat event

I have one 15" sub and orion 2500D and one battery.

I have an amp powering my speakers but i will take that out if that bumps me up a class

thanks

And its for USACI

Outlaw and streetbeat

ThomasG
06-11-2007, 07:52 PM
anyone?

Fear Of Theive
10-01-2007, 11:27 PM
Well my turn for help :)

I'm Trying to find out what class to do in meca.

Setup.

Vech: 1997 F150 Ext Cab(3rd Door, Took out backseat can put it back)

First time competing ever.

Sub Stage: Fi Bl 15 Fullyloaded- Amp: Crunch 1500\1 (should upgrade don't know what though)

Battery:Yellow Top(Biggest i can have in Amature)
Box: 4cubes at 32hzish.

I do not know what my truck peak's at and i know before i figure that out i need the amp i'll be using mostly. So if you have any idea's on a amp please pm me.

But my question is. Would this be good enough for As1-3? All i want is to bring home a trophy or something. 3rd isn't a problem for me :)

What i'm saying is, if you were in my shoe's what would you do?

Fear Of Theive
10-01-2007, 11:29 PM
Also anyone with a tl i can use to test in the Ohio area? i'm in Akron btw.

oldschool4me
11-17-2007, 02:42 PM
what define the classes in a comp these days? i havent been to one since the early 90s. are they still 1-100, 101-250, 251-500, 501 and up??? reason im wondering is that i am planning a new project for the spring and am wanting to be in the 100 w class. i have the sub amps that i plan to use. 2 crossfire 15hc amps rated at 15w x2. so thats 60watts, but they put out 370 underated watts at 1/2 ohm each. doubtful i can find an amp rated at 10w x 4ch for highs. so im going to probably go with another 15hc, punch 40, promos 12, us usa25, or something similar. anyone know or a 4ch thats rated at 40w let me know please. not sure of the vehicle yet have to see what i end up with. figureing crx, astro van, bronco, full size ext cab truck. and the vehicle will determin the subs and quantity of subs.

Van man
03-29-2008, 01:43 PM
umm...i have a 1991 GMC Safari van...it was a cargo van everything was stripped...there are 2 bubble circle windows in the back and the front windsheild and the driver and passanger windows and thats it...has 2 front seats and the person that owned it b4 me...covered it in hard plastic panels and rivited it...i have 2 10s in it right now powered by a lightning audio 750 and im impressed about how it hits...but i have 2 12" kicker comp VRs and im throwing them in a slanted ported box...im hoping that it sounds twice as loud but yea...lol any input would be nice:D

99durango5.9L
04-24-2008, 09:32 AM
heres my question.....it's a while away but im stoked there is a competition near my home i'm going to enter....its going to be my first one....unless something comes up before then....but i wanted to know it if makes a difference where you box sits in my truck?....right now its pushed all the way in the back, would moving it up closer to the front make any difference? :confused:

Ed Lester
04-24-2008, 04:33 PM
quote
99durango5.9L

heres my question.....it's a while away but im stoked there is a competition near my home i'm going to enter....its going to be my first one....unless something comes up before then....but i wanted to know it if makes a difference where you box sits in my truck?....right now its pushed all the way in the back, would moving it up closer to the front make any difference?
quote
-----------------------------------------------------------------------------------------------------------

It does make a difference. If its in a durango one of the best setups is subs up, ports back and have the ports about 6-12 inches from the hatch. If subs are firing back then the same 6-12 inches would work. I suggest testing and testing. Try 6 inches one time and 12 another.

Ed Lester
04-24-2008, 04:40 PM
Just looked at your pics, flip your box around and you'll gain at least 3 dB

99durango5.9L
04-24-2008, 06:53 PM
Just looked at your pics, flip your box around and you'll gain at least 3 dB


really why is that?....

99durango5.9L
04-25-2008, 12:28 PM
can someone tell me....why tho i would get more if i faced the port towards the back?....just the way the air moves?

btdickey99
04-25-2008, 12:32 PM
Just looked at your pics, flip your box around and you'll gain at least 3 dB

man thats a bold statement

99durango5.9L
04-25-2008, 12:46 PM
man thats a bold statement

what do you think?....would i score better with them towards the back?

Ed Lester
04-27-2008, 05:43 PM
Bold statement maybe but it comes with 14 years experience in SPL.

Its all about wave alignment. In SUVs and hatch cars, you usually have a lower cabin resonance than trunk cars. Having the subs face up or back will allow the source wave to fill the entire length of the vehicle. If the are facing forward from the back of the car then the source wave will hit the windshield with a resonant frequency higher than what the cabin resonance is. Then the the reflected wave from windshield to the back will have to travel further and have a lower resonant frequency. So basically you are creating a harmonic resonance in which the peak frequency of the source wave does not match the reflected wave. You want them both to match as much as possible to create higher SPL.
Walled vehicles and trunk cars with the trunk sealed off dont really have any airspace behind the source (subs) so they can have the same resonance on the source wave and the reflected wave.

The theories are here for your reference, you can try it if you want and see if the theory is correct. I always suggest test and tune as much as possible. Cant hurt to just try.

Supergumby5000
04-27-2008, 05:49 PM
I got a question, but i dont know how SPL related it is.

anyways, i have a chevy avalanche, with the sub box in the bed of the truck (blowing into the rear seats). There is about a 1/4" gap on each side of the box, giving room for air to blow into the bed of the truck.

I've been contemplating foaming/siliconing/something the gaps on my next instal this summer. Should i expect to see improvements or will this be a waste of time?

Ed Lester
04-27-2008, 05:53 PM
1/4 inch gap is not big enough for low frequency waves to fit in, but sealing it will help with building pressure in the cabin. So basically it can raise SPL if your numbers are already high but wont help much if they arent too high.
The main thing it will help with is SQ. It could sound better when all sealed up.

99durango5.9L
05-06-2008, 11:49 AM
Bold statement maybe but it comes with 14 years experience in SPL.

Its all about wave alignment. In SUVs and hatch cars, you usually have a lower cabin resonance than trunk cars. Having the subs face up or back will allow the source wave to fill the entire length of the vehicle. If the are facing forward from the back of the car then the source wave will hit the windshield with a resonant frequency higher than what the cabin resonance is. Then the the reflected wave from windshield to the back will have to travel further and have a lower resonant frequency. So basically you are creating a harmonic resonance in which the peak frequency of the source wave does not match the reflected wave. You want them both to match as much as possible to create higher SPL.
Walled vehicles and trunk cars with the trunk sealed off dont really have any airspace behind the source (subs) so they can have the same resonance on the source wave and the reflected wave.

The theories are here for your reference, you can try it if you want and see if the theory is correct. I always suggest test and tune as much as possible. Cant hurt to just try.

i wasn't doubting you....just asking why....sounds good, just standing the subs upright i noticed a difference....

expo5.0
05-11-2008, 10:38 PM
for a competition outside of any of the ruling bodies-

what do you guys think is the fairest/most fun for the most people so far as-

1. sensor location
2. engine running or not
3. music/tone selection (i'm thinking leave it open to the competitor)
4. car sealed up or not (can they crack a window if they choose?)
5. any other things you foresee becoming questions?

Ed Lester
05-12-2008, 09:56 AM
I say leave the sensor on the windshield but you dont have to be exact with measurement.

Engine running for all classes but limit them to rev to 2000-3000 RPM for safety.

Let them play whatever they want. Tones/music, CDs. IPODs, whatever.

Cars sealed because if they dont fully understand SPL, Opening windows and doors can hurt SPL and/or damage subs.

Clssification, define wall classes. If the enclosure is too high is it a wall? dB Drag's limit is the window line. NSPL is very relaxed and common sense says if its only a few inches above the window line, its not a wall.

Amp limits, you dont want a 40,000 watt system going against a 1,000 watt system.

Sub limit. 1-2 subs shouldnt go against 8-12 subs

expo5.0
05-12-2008, 07:04 PM
yeah-

I will be flexible with the classes- setting them completely after i see who/what shows up

the other things you said make sense as well



plan is to have "open" qualifying letting people come through anytime they want and then later inviting the top qualifiers in each class back for a head to head competition.

any other thoughts?

treasony
05-27-2008, 09:48 PM
got a question...
how much does it help to deaden the roof of a car? I was told if I deaden my roof, that should pick me up a lil on db's

big dawg
07-22-2008, 12:56 AM
ok guys. i read all the way up to page 4 in fear that i would repeat a question so if i did, I am sorry.
I have an 01 bonneville SE. ***** for spl from what i hear. In it I have two diamond audio D6 15's and a Diamond D3 1000.1 on each sub. My box is 6 cubes and tuned to about 35hz. I have never competed before but i plan on it. Here are my main questions
How do i set my gain, crossover, bass boost and head unit volume?
Should i pull the fuses on my 4 channel amp?
What class would my system fall in?
What would be a good track to play if i cant play tones?
Do you guys think I can hit around 145db's?

Anwar ( Team Pi
12-11-2008, 08:24 AM
Hi Guys, i am a new member and will love to get your insight on a few things.

i am a stock 1 competitor and currently doing a 155.9db on iasca world meter.

my vehicle is a opel corsa lite, and is tuned in at 55hz. playing 2 starsound duel two with 2 starsound 5000z in tandum.

my goal is to get to the 157db mark.

i have lots of pic and videos to share but it is easy to email them to you, if you interested. please drop me an email [email protected]

looking forward to getting stronger...:D

tinmanchris217
09-14-2009, 09:09 PM
I know this thread doesn't get much action, but ...

I was reading in the early pages that car peaks usually happen 4-10 Hz above your box freqs. If my cabin gain peaks at 53 Hz, I should make a few ports that span the range 43 Hz --> 49 Hz.

Is this a good plan, regardless of box volume? I was under the impression that tuning frequency for your peak changed with box IV.

Side Note:
Good rule of thumb mentioned was "port area" = Sd ... This makes more sense for SPL work, since we can use monster or tiny boxes, and tend to change them on the fly.

ex: 2 10's, it'll be ~100 sq in. much easier than 16 sq/cf.

VisceralSound
05-16-2012, 09:13 PM
Question regarding the upcoming show at Audio Designs in Winona. There's an IASCA event "Bass Boxing" and I feel very interested in doing the flyweight division battle, I know there is a $30.00 entrance fee at the gate, but do I need to upgrade my IASCA membership online to competitor (paying the 35 some dollars).

gumby688
10-10-2012, 12:09 AM
Ok going to my first USACI event this weekend have only competed in NESPL events so far. 1 I am wondering which would be the best class for me and 2 where is best placement for the mic. I am running 3 RF 12inch d2 HX2's running off a powerbd 1500 amp @1.33ohms and a punch 125.2 on my mids and highs my enclosure is behind the rear seat and at window level. I have a 2000 ford explorer sport 2 door for NESPL they put the mics on the windshield passenger side from reading the USACI rules I can put the mic anywhere infront of the b pillar.