Get Your SPL Related Questions Answered Here!

[linksyz 10+ year member]

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' date=' 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. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif[/quote']

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 //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[bigbassman Premium Member]

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 10+ year member]

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 5,000+ posts]

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 10+ year member]

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 //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif. 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 //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif. 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 linksyz@comcast.net for few anwers)
Thanks,

Nino

Not OT at all. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

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 //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[bigbassman Premium Member]

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 5,000+ posts]

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 //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Loyd L.

You guys are gods. //content.invisioncic.com/y282845/emoticons/clap.gif.178cba2c538c68e720c727fcb024b19c.gif I have been preaching this very same statement for years now. //content.invisioncic.com/y282845/emoticons/clap.gif.178cba2c538c68e720c727fcb024b19c.gif//content.invisioncic.com/y282845/emoticons/clap.gif.178cba2c538c68e720c727fcb024b19c.gif//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[kickerlivinloud 10+ year member]

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 10+ year member]

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 Premium Member]

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 //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Loyd L.

 

[bigbassman Premium Member]

You guys are gods. //content.invisioncic.com/y282845/emoticons/clap.gif.178cba2c538c68e720c727fcb024b19c.gif I have been preaching this very same statement for years now. //content.invisioncic.com/y282845/emoticons/clap.gif.178cba2c538c68e720c727fcb024b19c.gif//content.invisioncic.com/y282845/emoticons/clap.gif.178cba2c538c68e720c727fcb024b19c.gif//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

you don't wanna play with me.... //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

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

wang

Loyd L.

 

[Bumpin' Yota 10+ year member]

you don't wanna play with me.... //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

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?

//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif lol jk

 

[ramos 5,000+ posts]

you don't wanna play with me.... //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

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 //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif One of these days brother man . I got to see the crazy eights //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Puggsley456 10+ year member]

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 10+ year member]

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.