PDA

View Full Version : Sub placement, does it matter?



MellowHype
03-29-2014, 10:54 AM
EDI:: Change of plan, ive now got two Type R's and am in the process of designing a box

Im going to have a go at building a new box, as my current running a type R @700 watts isnt very loud and i think its got a lot to do with the box.

the current box is 2.0cbf 32hz before displacement.
the new will be 2.52 @ 30 hz before displacement.

My current sub is in its box like number one in this pic, is that a bad place to mount it? with the port wall just behind it?
i was thinking of going with it like this (number 2)

http://i1243.photobucket.com/albums/gg557/MellowHigh/subbox30hz252_zps49dc8edd.png

does that make a difference at all?

and could anyone tell me what the displacement would be?
my specs

Mounting Depth: 162mm (6-3/8'')
Mounting Diameter: 275mm (10-13/16'')
Displacement: 0.100ft^3
Added Volume: 0.090ft^3


Really appreciate any help

bbeljefe
03-29-2014, 10:58 AM
Yes, placement matters. Both where the sub is mounted in the box and were/how the box is placed in the vehicle.

Location one is better because the sub isn't loading directly into the mouth of the port.

MellowHype
03-29-2014, 11:02 AM
Yes, placement matters. Both where the sub is mounted in the box and were/how the box is placed in the vehicle.

Location one is better because the sub isn't loading directly into the mouth of the port.
ahh ok, thanks alot.

Ill go with that then.

Also a couple more things, is fibreglassing the inside worth it? i can only find a tin for 25 and i suppose im not going to need all of it.

and are 45 degree cuts a must for the corners?

im asking as i dont want to build another for it to still not sound very good.

T3mpest
03-29-2014, 11:13 AM
ahh ok, thanks alot.

Ill go with that then.

Also a couple more things, is fibreglassing the inside worth it? i can only find a tin for 25 and i suppose im not going to need all of it.

and are 45 degree cuts a must for the corners?

im asking as i dont want to build another for it to still not sound very good.

No they aren't. They are nice things that usually helps, and can show off woodworking skills, but they rarely even make audible difference.. Just make sure you have a good amount of port area and that fixes 90% of the problems associated with ports.

macsdad
03-29-2014, 11:20 AM
Yes, placement matters. Both where the sub is mounted in the box and were/how the box is placed in the vehicle.

Location one is better because the sub isn't loading directly into the mouth of the port.If he did a labyrinth type port, would that eliminate the unloading in the port? Giving him more options?

MellowHype
03-29-2014, 11:46 AM
No they aren't. They are nice things that usually helps, and can show off woodworking skills, but they rarely even make audible difference.. Just make sure you have a good amount of port area and that fixes 90% of the problems associated with ports.


Ok thanks.

how does the design in the OP look? i want to keep it very simple

bbeljefe
03-29-2014, 11:51 AM
ahh ok, thanks alot.

Ill go with that then.

Also a couple more things, is fibreglassing the inside worth it? i can only find a tin for 25 and i suppose im not going to need all of it.

and are 45 degree cuts a must for the corners?

im asking as i dont want to build another for it to still not sound very good.

Wave guides (the 45 corner braces) make very little difference so if you don't have a table saw, don't worry about them. Fiberglass is not necessary unless you're running a lot more power than you are and, as Tempest said, correct port area is very important.

The box and the port area you have in the drawing above look to be good for that sub.

bbeljefe
03-29-2014, 11:53 AM
If he did a labyrinth type port, would that eliminate the unloading in the port? Giving him more options?

No. If the port provides that much acoustical suspension, it's too small. Doesn't matter what it's shaped like.

T3mpest
03-29-2014, 11:59 AM
If he did a labyrinth type port, would that eliminate the unloading in the port? Giving him more options?

You really don't want to bend a port more times than necessary anyway.. Airflow in a port needs to be as smooth as possible, especially since turbulence in the middle of a port wont' be flushed out the ends and will cause compression easier, even if you don't hear chuffing.

MellowHype
03-29-2014, 12:14 PM
Wave guides (the 45 corner braces) make very little difference so if you don't have a table saw, don't worry about them. Fiberglass is not necessary unless you're running a lot more power than you are and, as Tempest said, correct port area is very important.

The box and the port area you have in the drawing above look to be good for that sub.

Thanks alot for your help, gonna start gathering materials and give it a go


Edit: oh yeah, and what would my specs be after displacement with that box in the OP??

Displacement: 0.100ft^3
Added Volume: 0.090ft^3

2.42cbf? what hz am i looking at roughly?

Loudmp5
03-29-2014, 12:35 PM
I suggest you download Torres box calc it's way more accurate than the re calc

bbeljefe
03-29-2014, 03:34 PM
Thanks alot for your help, gonna start gathering materials and give it a go


Edit: oh yeah, and what would my specs be after displacement with that box in the OP??

Displacement: 0.100ft^3
Added Volume: 0.090ft^3

2.42cbf? what hz am i looking at roughly?

After sub and port displacement what you have is 2.24ftⁿ and tuning is ~30.5 Hz.

MellowHype
03-29-2014, 03:57 PM
After sub and port displacement what you have is 2.24ftⁿ and tuning is ~30.5 Hz.

the 2.24ft^3 is fine (most recommend 2.25-2.5 for single 12 type R), and i cant get much bigger than that in my boot, so if i mess around with port diameter i can aim for 31.5hz on RE Calculator and 32hz is what ill get?

sorry to bother you with these questions i just dont know how to work it out, quite new to this kinda stuff

hispls
03-29-2014, 04:31 PM
Yes, placement matters. Both where the sub is mounted in the box and were/how the box is placed in the vehicle.

Location one is better because the sub isn't loading directly into the mouth of the port.

Of course the front wave from the cone may cause some issues with the mouth of the port on the outside if it's in #1 (http://www.caraudio.com/forums/usertag.php?do=list&action=hash&hash=1) .

OP, couldn't you go right in the middle? That way the sub isn't too close to either opening of the port.

I find that position of the box and port in the vehicle has a much more dramatic effect on output and response than just moving the sub from one side to another of the baffle.... moving position of the sub (to the top, back, or side) of the box may also make a noticeable difference. Nothing for it but to build a dozen boxes for that car, buy a meter, and test..... OR if you can find someone who has built a lot of boxes for the same car they can probably tell you what works best.

bbeljefe
03-29-2014, 05:50 PM
the 2.24ft^3 is fine (most recommend 2.25-2.5 for single 12 type R), and i cant get much bigger than that in my boot, so if i mess around with port diameter i can aim for 31.5hz on RE Calculator and 32hz is what ill get?

sorry to bother you with these questions i just dont know how to work it out, quite new to this kinda stuff

I have no idea what kind of results you can expect from that calculator because I don't use it. I've heard a lot of people say it's not accurate but the times that I've double checked it, it has been pretty close.

And no worries, I'm happy to help any time I can.

MellowHype
03-30-2014, 06:23 PM
Of course the front wave from the cone may cause some issues with the mouth of the port on the outside if it's in #1 (http://www.caraudio.com/forums/usertag.php?do=list&action=hash&hash=1) .

OP, couldn't you go right in the middle? That way the sub isn't too close to either opening of the port.

I find that position of the box and port in the vehicle has a much more dramatic effect on output and response than just moving the sub from one side to another of the baffle.... moving position of the sub (to the top, back, or side) of the box may also make a noticeable difference. Nothing for it but to build a dozen boxes for that car, buy a meter, and test..... OR if you can find someone who has built a lot of boxes for the same car they can probably tell you what works best.

If thats whats recommended, then ill do it, you guys no more than me lol

Any yeah i think i noticed an increase in spl when i turned my box over faced up from a normal upright, but that was probably because the woofer was sitting so close to the tail gate


And another thing, that RE Box calculator says for the side cuts, 15.25 x 12 x 15.25 x 12.. Why twice?

hispls
03-31-2014, 01:48 AM
If thats whats recommended, then ill do it, you guys no more than me lol

Any yeah i think i noticed an increase in spl when i turned my box over faced up from a normal upright, but that was probably because the woofer was sitting so close to the tail gate


And another thing, that RE Box calculator says for the side cuts, 15.25 x 12 x 15.25 x 12.. Why twice?

It is always worth experimenting with which direction is best to aim the woofer and moving it closer and farther from the rear wall of the vehicle can make a noticeable difference. Most people with hatchbacks do sub up and port to the rear or port to the side. Trunks I've seen go sub back port to side, or sub up and port front. You'd do well to do a little research on what works well for your vehicle before you start cutting wood. From what I understand it's not so cheap in Europe as it is over this way. At 36$ a sheet people in USA can afford to build a few boxes to test, if it's 80$ or more that gets a little painful.

MellowHype
03-31-2014, 12:54 PM
It is always worth experimenting with which direction is best to aim the woofer and moving it closer and farther from the rear wall of the vehicle can make a noticeable difference. Most people with hatchbacks do sub up and port to the rear or port to the side. Trunks I've seen go sub back port to side, or sub up and port front. You'd do well to do a little research on what works well for your vehicle before you start cutting wood. From what I understand it's not so cheap in Europe as it is over this way. At 36$ a sheet people in USA can afford to build a few boxes to test, if it's 80$ or more that gets a little painful.

I can actually get an MDF sheet (3/4 inch) for about the equivalent to $23, or get a sheet cut down into all my pieces for around $33, thats an 8x4 sheet.

I have a hatchback and since the RE box calculator is all im familiar with itl have to be a simple design on that, so its gonna be sub up & port up. Im just hoping the extra capacity inside this box will give a nice difference. Currently running in a box that was 2.0 ft^3 @32 hz before displacement, and the new will be 2.5ft^3 and whatever hz it needs to be that after subs in its at 32hz (still dont know how to work it out and cant find much on google)



Ive also just found out i can run my current dual 4 ohm at 1 ohm if i get another sub, which means ill be running 500watts each, seems like a good idea and im only loosing 200rms of power but gaining 12" more sub :)

MellowHype
03-31-2014, 02:36 PM
Heres my current set up and space restrictions, sorry for the bad quality

http://i1243.photobucket.com/albums/gg557/MellowHigh/pic1_zpsc1dee31a.png
http://i1243.photobucket.com/albums/gg557/MellowHigh/pic2_zps328ca1f2.png


So ive got about half inch i can squeeze between the amps, so il have a little more room to mount the sub, thats currently a 12" sub on a 12" high piece.

decided another 4ohm sub running both at 1 ohm is what i want to do, so as soon as i know what to do with the box i can go purchase it and get going.

I can get a maximum of 37" side to side, and i think it was 34" between where the subs can be mounted to avoid them hitting the plastic bits (i marked one in yellow)


Can i use the same port as the one in the OP or will it have to be completely different? like port in the middle or what ever

ancorp
03-31-2014, 04:15 PM
So you can either make box 37" wide but less tall, or 34" and taller. If you go 34" wide, how tall and deep can you go maximum? You can always mount the amps on the left and right side of the box below those plastic bumps if you make the box 34" wide.

fivedollapizza
03-31-2014, 04:25 PM
you should definitely download Torres to double check everything. completely design the box in the RE builder so you know what you're looking at, then take those numbers and put them into Torres. i bet the tuning is higher than RE says it really is.

good call on asking everyone here. i've only had to rebuild my box once after questions on these forums, and that was just to put the port to the drivers side (which was actually suggested to me, i just didn't listen lol)

MellowHype
03-31-2014, 04:54 PM
So you can either make box 37" wide but less tall, or 34" and taller. If you go 34" wide, how tall and deep can you go maximum? You can always mount the amps on the left and right side of the box below those plastic bumps if you make the box 34" wide.
Just checked and if i had it so that it was 34" wide and centred i could have it a maximum of 3.5 inches higher, any more or even 3.5 and the subs will be slapping against the parcel shelf, and the port will be like an inch or two from the shelf.
removing the shelf isnt an option either i cant risk displaying the system overnight etc




you should definitely download Torres to double check everything. completely design the box in the RE builder so you know what you're looking at, then take those numbers and put them into Torres. i bet the tuning is higher than RE says it really is.

good call on asking everyone here. i've only had to rebuild my box once after questions on these forums, and that was just to put the port to the drivers side (which was actually suggested to me, i just didn't listen lol)

ive got a youtube video open for that im gonna watch it and learn how to use it to make sure.

Btw, just to be clear the box will be like in the OP with both 1&2 subs, and then just flipped up so that the subs facing up.

Can anyone tell me how i can work out displacement and hertz after sub displacement? once i know that and how to go about placing the 2nd port wall im ready to go and order the second SWR-1243d, i think its gonna be hard to find one as the new R is out.


I watched 'ExoContralto' sub box tutorial and he used the RE calculator and just moved the second portwall but i dont understand how he got the 3.5" measurement

said video
https://www.youtube.com/watch?v=84PAxNUv8xc
@ 2:40 ish

Edit: probably me being an idiot, just realised its the width of the actual port, might aswell make sure thats correct. I just move the second wall but make sure it leaves the same size gap as the port opening

fivedollapizza
03-31-2014, 05:58 PM
i don't remember off hte top of my head which spec is subwoofer displacement, but .07 is a good general to add in for a 12" driver.

when you throw your numbers into Torres there will be a box to input additional displacements for the driver and any bracing.

exactly correct about where the second port wall goes. just stays port width away from the back of the box.

MellowHype
03-31-2014, 06:12 PM
i don't remember off hte top of my head which spec is subwoofer displacement, but .07 is a good general to add in for a 12" driver.

when you throw your numbers into Torres there will be a box to input additional displacements for the driver and any bracing.

exactly correct about where the second port wall goes. just stays port width away from the back of the box.

Mounting Depth: 162mm (6-3/8'')
Mounting Diameter: 275mm (10-13/16'')
Displacement: 0.100ft^3
Added Volume: 0.090ft^3

In that video it states to aim for 31/30hz to get a target tuning of 32hz after displacement, so im gonna go with that, and aim for as much ft^3 as i can squeeze in and use a similar port to he used in the video.


So say im using dual subs and the box ends up 3.0ft^3 with each sub =

Displacement: 0.100ft^3
Added Volume: 0.090ft^3

what would it be after displacement? i dont understand how its worked out or what added volume is

From what i remember people on here used to recommend 2.0-2.5ft^3 for a single R so i really need to make this box as big as i can squeeze in


Edit:
this is what i can do @ 37 inches wide
http://i1243.photobucket.com/albums/gg557/MellowHigh/box37_zps3baa46a3.png

When coming up with the 34" wide box i think i realised how much more room i can potentially have but im gonna need to double check this all over tomorow when ive relaxed a bit lol, i just really wanna get this build going.

Potentially can have this, but i know for a fact the amps will have to be mounted on the sides of the box
http://i1243.photobucket.com/albums/gg557/MellowHigh/box34_zpsa515078a.png
So a lot more volume than the 37", im just worried about the port only being 2.5". However if i bump it to 3" the second wall has to be 18" and thats not gonna fit the in the way like the 1st pic (how either will be with the second wall like that)

Thanks for all your help guys i really appreciate it.

MellowHype
04-01-2014, 12:22 PM
I have now found out another version of my sub isnt gonna be easy to get, the sub is discontinued in everyone of my local/online shops. Might have to sell mine and get two newer type R's

ancorp
04-01-2014, 05:04 PM
Your best bet for your space - 34" wide, 19" tall, 14" deep - One 16" long 6" diameter aero/flared round port, at the side of the enclosure closer to the bottom. That'd give you 4.11 cubes before displacement, 0.2 for the two subs, 0.26 for the port - 3.65 cubic feet net. 32HZ tuning after all displacements. Would work great for either these or the newer gen Type Rs

MellowHype
04-01-2014, 07:34 PM
Your best bet for your space - 34" wide, 19" tall, 14" deep - One 16" long 6" diameter aero/flared round port, at the side of the enclosure closer to the bottom. That'd give you 4.11 cubes before displacement, 0.2 for the two subs, 0.26 for the port - 3.65 cubic feet net. 32HZ tuning after all displacements. Would work great for either these or the newer gen Type Rs
For an aero port, is that just one big box with a hole cut out and 16"long PVC pipe with flared out ends slotted into the hole? nothing else going on inside the box?

Might give that a go, but im now looking at trying to get a couple of sandown sa-12's shipped because i realise how stupid UK's prices are, a type R costs me the equivalent of $233, where a SA-12 is $199, not sure what the shipping rates would be though for 2 12's



Could anyone tell me whether im going to notice a big difference going from one 12 @ 700w (2ohm) to 2 x 12 @1000w (1ohm). Does that extra 200 watt become irreverent when losing 200watt but gaining another 12? Just worried as it started being a cheap quick upgrade with one more sub, now im gonna need two new subs no matter what

MellowHype
04-02-2014, 03:01 PM
For an aero port, is that just one big box with a hole cut out and 16"long PVC pipe with flared out ends slotted into the hole? nothing else going on inside the box?

Bump

Just went and collected the two R's, gonna go get some wood cut tomorow and get building over the weekend.

My next step is probably finding a 1ohm stable 2000rms amp for a reasonable price, the R's will have to just be on 500rms for a while.

MellowHype
04-03-2014, 05:38 PM
Turns out i cant get either of those sizes in my trunk! i wasnt taking into account the fact that the seats slant as the height of the box rises, or the fact that i need to have room to mount my amps


The true size ive come up with and i think its the best i can do with a simple box, is 33 wide, 19" height and 15" depth, then mounting the subs on top. I think it can be done but the subs might be tight, due to leaving room for the portwall (2.5 port, and second wall being parallel to 1st with 2.5" gap between), but two 12"s should fit.

Ive made a mock up box from proplex sheets, of those dimensions and im going to see if it fits tomorow.

That gives me a 3.6ft^3 31hz box before displacement, is that just too small for two R's? a 2.5" port seems small aswell?



I can possibly gain another inch or two in height, giving me a max of 4ft^3, but i will have to lose my parcel shelf, and i dont want to display my system overnight etc, and covering it with a sheet just makes it obvious ive got something to hide. could anyone suggest what i could do about that? i was thinking of just covering it with a thin carpet that matches the cars interior to try to make it look like a shelf, and just remove it and tuck it behind the sub when i leave the car.


This is what my boot looks like
http://www.hourcar.org.uk/htmlimages/cars/640x480/corsa_boot.jpg
http://thumbs3.ebaystatic.com/d/l225/m/mcgoGr23H3T21ura974lmFQ.jpg

ancorp
04-03-2014, 06:23 PM
33 x 19 x 15 is actually a bit bigger then the 34 x 19 x 14 I was discussing earlier. The Rs will do just fine. But yes, do an aero port to save space. They're more efficient then slot ports. They are indeed PVC or cardboard (sonotube) pipes with flared ends. One 6" will be fine.

MellowHype
04-03-2014, 06:43 PM
33 x 19 x 15 is actually a bit bigger then the 34 x 19 x 14 I was discussing earlier. The Rs will do just fine. But yes, do an aero port to save space. They're more efficient then slot ports. They are indeed PVC or cardboard (sonotube) pipes with flared ends. One 6" will be fine.

Ill give that a go then, could you tell me what the ft^3 would be at 33 x 19 x 15 with a 6"x16" like you said earlier? also what the htz would be? just as its a bit different from the measurements you gave before.

Its not a bad idea to go aero as ill have more room to mount the subs, just i have no experience on them so ill have a look around

And one more thing, if im not looking to get extreme lows and im more interested in SPL, is a higher tuning frequency a good idea? like would 38hz be louder than 32 hz?

ancorp
04-03-2014, 08:31 PM
Youd be at around 3.84 cubes and 31.2hz or so. If you're looking for a higher spl then yes, tune higher. Its easier to adjust tuning with an aero port. Just take it out, chop off some of the pipe, reattach flared ends. If you go with a 6" diameter 9" long port, you'll be tuned to 38hz with about 3.95 cubes of net volume after all displacements. Start with a 16" port first and see how she sounds, and then shorten it piece by piece until it sounds good to you.

ancorp
04-03-2014, 08:34 PM
If you can locate a 8" flared port (or make one), then make it 21" long and you'd have 38hz with about 3.5 cubes of net volume. The larger port area and smaller box might help you peak for greater SPL. Tuning above 38 might be beneficial too, depends on the vehicle.

MellowHype
04-03-2014, 09:24 PM
If you can locate a 8" flared port (or make one), then make it 21" long and you'd have 38hz with about 3.5 cubes of net volume. The larger port area and smaller box might help you peak for greater SPL. Tuning above 38 might be beneficial too, depends on the vehicle.



Thank you for your help bro, gonna crack on with this over the weekend. I just need to find some PVC and learn how a aero port is correctly made and im good to go

psych0ticnemes1
04-04-2014, 09:51 AM
At 3.6 cubes net you're better off getting a single 15", which is unfortunately because you just bought the pair of Rs, but 1.75 cubes per 12" R is plenty.

As for a 2k 1 ohm amp, what is your budget? I'd recommend this: Q1-2200D (http://www.soundqubed.com/Q1-2200D_p_31.html)

Those subs will take the power well and it's a great amp. I run a 15" Type R off 1.5k right now. They're tough to beat for the price.

Good luck.

MellowHype
04-04-2014, 12:35 PM
At 3.6 cubes net you're better off getting a single 15", which is unfortunately because you just bought the pair of Rs, but 1.75 cubes per 12" R is plenty.

As for a 2k 1 ohm amp, what is your budget? I'd recommend this: Q1-2200D (http://www.soundqubed.com/Q1-2200D_p_31.html)

Those subs will take the power well and it's a great amp. I run a 15" Type R off 1.5k right now. They're tough to beat for the price.

Good luck.

Surely two R's will out perform a single 15" even if the enclosure is on the small side??
Also, ive realised 2k 1ohm is definitely going to need an alternator upgrade so im gonna stick with 500 each for now, but thanks for the recommendation



Im hoping to go and get the materials tomorrow, just im not 100% on how to make an aero port. Do i just need one tube of 6" and then flare one end? Surely i need the ends slightly larger than 6" so that they can be stuck on the straight pipe to change tuning, and also to have the inside end flared?
Can they just look like this?
http://i1.ytimg.com/vi/XFMMVOH6ero/maxresdefault.jpg

So i grab one 6 inch radius 16 inch long tube, flare one end, slightly file the other and slide it in the box and screw it down?

Also, the port is supposed to look like this? not sticking out of the box.
http://i1243.photobucket.com/albums/gg557/MellowHigh/BoxAero405_zpsd08a6ca0.png

psych0ticnemes1
04-04-2014, 03:56 PM
Two 12"s won't automatically be louder than a 15" simply because of the extra cone area, but in proper boxes you could guess that they would be.

The port can be internal or external, but if it's internal, it'll take up space in the box so you have to figure that in when determining net box volume and tuning.

MellowHype
04-04-2014, 06:29 PM
Two 12"s won't automatically be louder than a 15" simply because of the extra cone area, but in proper boxes you could guess that they would be.

The port can be internal or external, but if it's internal, it'll take up space in the box so you have to figure that in when determining net box volume and tuning.

Ok thanks, got me a bit worried now though lol, i could go return the R's and get a 15" sub @ 1000wrms 1ohm and have it in a 3.5 slot ported box, not sure how that would compare to 2 12" R's @ 500 each.
And yeah i understand a 15 could be louder depending on the setup / brand etc, i think ill have around 4ft^3 before displacement of subs and port so i hope the box should just about be big enough.

The port has to be internal aswell as i dont have the room for external.
Im thinking of just filing and smoothing one end of the pvc, and sliding it in with the aero/flared end on the outside as i dont see any other way, other than using a coupler which just means more displacement.

ancorp
04-04-2014, 07:11 PM
Well two 12 Type Rs should definitely be louder then one 15" Type R in the same box. More cone area and motor force, and less power compression. You need to flare the port or you risk port noise and choking. But it might not be noticeable. My calculations were with the port inside the box. Don't see the point of making the port external, unless its just the flared part. Yes, flaring both ends is best, but if you can only do one, do the one on the outside.

This is what you need Precision Port 6" Flared Port Tube Kit | 268-354 (http://www.parts-express.com/precision-port-6-flared-port-tube-kit--268-354)

MellowHype
04-04-2014, 07:35 PM
Well two 12 Type Rs should definitely be louder then one 15" Type R in the same box. More cone area and motor force, and less power compression. You need to flare the port or you risk port noise and choking. But it might not be noticeable. My calculations were with the port inside the box. Don't see the point of making the port external, unless its just the flared part. Yes, flaring both ends is best, but if you can only do one, do the one on the outside.

This is what you need Precision Port 6" Flared Port Tube Kit | 268-354 (http://www.parts-express.com/precision-port-6-flared-port-tube-kit--268-354)

I was looking at that earlier, however im from UK and cant find anything decent here.

My friend has a peice of 6" PVC pipe for me, so i know i can have one flared edge, i just dont know how im going to get both ends flared and then get it through a 6" cut out..

Maybe flaring both ends of a long pipe, cutting one end, and with the cut off flare the other end of it ever so slightly so that it might slip on to the other longer peice, if that makes sense. But even that i doubt would work.

ancorp
04-04-2014, 10:31 PM
You could indeed make the outside flare bigger, and cut a bigger hole. Or simply make a flare separately and then insert it into the box through one of the sub holes and glue/tape it onto the pipe inside.

psych0ticnemes1
04-05-2014, 07:20 AM
If you have the 12"s, use them. They'll work great for you. Report back when you get this thing built and post a video.

hispls
04-05-2014, 10:45 AM
I have seen pictures of people flaring their PVC pipes by heating the tip in a pot of hot frying oil and building a jig to press it onto to stretch the end into a flare. Seemed a bit of a process to do but the results looked excellent.

MellowHype
04-05-2014, 02:36 PM
You could indeed make the outside flare bigger, and cut a bigger hole. Or simply make a flare separately and then insert it into the box through one of the sub holes and glue/tape it onto the pipe inside.

If using tape is fine, then thats what ill do, makes the job nice and easy i just was unsure whether tape is good enough. Got strong blue gaffa tape and might even use a bit of sealant round the cut.


If you have the 12"s, use them. They'll work great for you. Report back when you get this thing built and post a video.

Will do, hopefully have the box done then get it in the car with subs in a day or two later. Just might have to buy another run of 4awg though as my amps are moving further from the battery and im not sure how much slack theyve got in them.


I have seen pictures of people flaring their PVC pipes by heating the tip in a pot of hot frying oil and building a jig to press it onto to stretch the end into a flare. Seemed a bit of a process to do but the results looked excellent.

not sure what you mean 'building a jig' but i have a heat gun and should be able to find a metal bowl anyway.


All the cuts done today and had a bit of an accident with the front peice
http://i1243.photobucket.com/albums/gg557/MellowHigh/DSC00416_zps5b41639f.jpg

going to have to use it still so ill just sand it down flush, it will just be a bit weaker than the rest..


I also have #6 (http://www.caraudio.com/forums/usertag.php?do=list&action=hash&hash=6) 1 5/8 Drywall coarse screws, what size should my pilot be?

hispls
04-05-2014, 09:04 PM
Heat Moulded Port Flares (http://www.subwoofer-builder.com/flares-25mm.htm)

Something like this to flare ports. Ive seen a thread where someone used a pot of hot oil to evenly heat large PVC he claimed that you need a lot of pressure to force the pipe open so he built some sort of lever press to smash down the PVC onto the mold.

MellowHype
04-05-2014, 09:15 PM
Heat Moulded Port Flares (http://www.subwoofer-builder.com/flares-25mm.htm)

Something like this to flare ports. Ive seen a thread where someone used a pot of hot oil to evenly heat large PVC he claimed that you need a lot of pressure to force the pipe open so he built some sort of lever press to smash down the PVC onto the mold.

interesting link with some good stuff but i dont have access to the tools to follow much from that

im just gonna get my 6"x14" pipe and flare both ends using a heat gun and a metal bowel, saw it in half, cut out a 6" hole in the box and assemble the port in the box and glue/tape together, similar to this

http://s7.tinypic.com/9jdp2u.jpg

hispls
04-05-2014, 09:30 PM
interesting link with some good stuff but i dont have access to the tools to follow much from that

im just gonna get my 6"x14" pipe and flare both ends using a heat gun and a metal bowel, saw it in half, cut out a 6" hole in the box and assemble the port in the box and glue/tape together, similar to this

http://s7.tinypic.com/9jdp2u.jpg

Use Google. Ive seen a method with a much simpler mold and the press lever was just some 2x4s

MellowHype
04-09-2014, 08:31 PM
Right, ive made a port with two flares, but im not sure whether theyre flared enough and its the best i could do with the bowl i was using.

http://i1243.photobucket.com/albums/gg557/MellowHigh/port1_zpsc53ea48f.jpg
http://i1243.photobucket.com/albums/gg557/MellowHigh/port2_zpsfb7e1651.jpg

Hopefully you guys think that looks ok, i will be painting it tomorow if so. (Edit: The cut out for the port is already in place leaving barely any room for more of a flare, i guess its staying as is, should have waited to get some advice but i wasnt thinking lol)
I have a coupler to join two peices so once i know the port length i will cut it into two and im ready to go


Could anyone tell me how long it needs to be for a target of 32hz? and also the displacement of it at the length needed for that? Im going to try 32 and if im not happy ill raise it slightly and aim for 36hz for more SPL.


The box dimensions (external) are 33" wide, 17.5" high and 15" deep. 0.75" MDF

The displacement of the sub is 0.10ft^3, and im using 2.


The inside of the PVC is 6" and the outside 6 19⁄64"

Appreciate any help!

MellowHype
04-09-2014, 09:00 PM
This is what im using to join the pvc
http://www.fairalls.co.uk/wp-content/uploads/2012/11/PUG566-300x300.jpg

MellowHype
04-10-2014, 12:02 PM
Using the 12Volt calculator i calculated that the port needs to be 14.5" long for 32hz, but i dont know how accurate that is.
Also would that be measuring from where the flare straightens out?

MellowHype
04-10-2014, 07:34 PM
Wasnt taking into account displacement of the subs in the above post ^

I went with 15.5" port giving me 34hz after displacement, heres how it looks.
http://i1243.photobucket.com/albums/gg557/MellowHigh/portin2_zpsef71f4d0.jpg
http://i1243.photobucket.com/albums/gg557/MellowHigh/portin1_zpsd4a9a1d3.jpg
http://i1243.photobucket.com/albums/gg557/MellowHigh/portin3_zps31088e60.jpg


As you can see the flare sticks out a bit and its going to have to stay like that, im just going to use the strongest sealant i can find to seal around (see 2nd pic) and it should keep it in place..


Can i get any opinions?

ancorp
04-14-2014, 01:42 AM
Looks great, did you put the baffle on and fire up the Type Rs yet?

MellowHype
04-14-2014, 12:15 PM
Looks great, did you put the baffle on and fire up the Type Rs yet?

Yep i have, however i made the mistake of assuming that going from 700 rms @ 2ohm to 1000 @ 1 ohm would mean turning my gains up, so i left the gains how they were and played some songs on full. Luckily it wasnt for too long though and i realise that my voltages need to be alot lower so i could have killed my amp.


Ill be re-setting gains in a little while

hispls
04-14-2014, 12:18 PM
That looks very nice for a first box! I'd have liked to see a bit more flare, but anything is better than nothing.

MellowHype
04-14-2014, 02:06 PM
That looks very nice for a first box! I'd have liked to see a bit more flare, but anything is better than nothing.

Its actually my second, and the 1st one was pretty bad lol. but thanks anyway

I know i really wished i spent more time on the flare, its just the only metal bowl i had would only flare it as far as that or the pipe would start collapsing in, needed a bowl with a smaller base. Would have been nice to flare more and screw it in flush.


Ive just set my gains again, and the two 12's are now no louder than my single R. Yesterday when i hadent touched the gains from before i bumped at full volume and was quite impressed, i could feel it in my throat lol

My leads for the meter i used before had broken so i found a pair at my work and tried them. The resistance from pos to neg wires on the meter was 1.5 ohm.. So i then tested the subs wires and it showed 2.5 ohm, so i guessed maybe they where abit out but just 1.5 ohm out? (my subs are or should be wired to 1 ohm)

When i first played the test track the multimeter was showing 50volts! this was gains untouched from when i set it to 700 rms for my single 12.
and i know for a fact that before with my brand new meter (although it was very cheap) was showing my target of 37 volts. I also played that sub at that voltage for over a year with absolutely no problems.

I went ahead and used the meter to back down from 50v to new target of 31volts (1000 rms @ 1 ohm), and the result was two R's sounding identical spl wise to my single R
So im hoping that the wires are just out as two subs, and a large improvement on box should definitely not be the same as my single R.

EDIT: I had also used the leads in another meter i found at work and it showed the same 50volts, so i think it has to be the leads

ancorp
04-14-2014, 08:27 PM
I personally never used any DMM to set anything. Just cranked it until I felt I was approaching distortion/clipping or low voltage. Turn it up and get those suckers moving.

MellowHype
04-14-2014, 09:54 PM
I personally never used any DMM to set anything. Just cranked it until I felt I was approaching distortion/clipping or low voltage. Turn it up and get those suckers moving.

Im now waiting until wednesday until the new leads get here, if its showing the same figure i might just do that.

Do you use a test track like 60hz or just chose one of your louder songs when doing it by ear?

ancorp
04-15-2014, 08:56 AM
No tones, just grab my favorite bass heavy songs.

These Type Rs are brand new?

MellowHype
04-15-2014, 12:10 PM
No tones, just grab my favorite bass heavy songs.

These Type Rs are brand new?

Yep brand new, annoying comparing the price to what you pay over in US, think i saw them on amazon.com for $120 each, i payed 140 each which is like $240.

Im now tempted to buy this 2nd hand Hifonics Brutus BRE (Elite), capable of 2500 @ 1 ohm, its just i dont know how you can test if an amp is in good condition when 2nd hand. Previous owner could have turned gain to max, blown a sub and just wants to sell it. Guess thats just the risk.,


Could anyone help me with my subsonic filter? Ive got a song that has a 26hz frequency that my subs miss because of how its currently set. Am i good to hit 26hz in a box tuned to 34hz?

Im using a tutorial on here just want to make sure im correct


SSF frequency by using the formula: SSF = Tuning*3/4 - 34hz x 0.75 = 25.5

Calculate the desired SSF voltage by using the formula: SSF_Voltage = 0.707*Sub_Voltage - 0.707 x 31.62 = 22.35 (that is going by 'Sub_Voltage is my gains setting voltage)

I then get my 25 hz test track and turn down the subsonic untill i see 22.35 volts?



Greatly appreciate all of your help in here btw helped me learn alot

hispls
04-15-2014, 12:31 PM
Where are you getting these voltage numbers? How have you verified the impedance of your sub at all these frequencies that you're testing?

MellowHype
04-15-2014, 12:59 PM
Where are you getting these voltage numbers? How have you verified the impedance of your sub at all these frequencies that you're testing?

Just going by the formula for working and setting gains by using a multimeter in a tutorial on here (scroll down to subwoofer part). Then using the subsonic filter setting part, thats where i got those frequency's above
http://www.caraudio.com/forums/amplifiers/63933-gain-setting-tutorial-42.html#post4104530


Subs are wired to 1 ohm and amp at 1000watts. square root of 1000 = 31.62v

I dont know what you mean by verified impedance at different frequency.

hispls
04-15-2014, 09:45 PM
Just going by the formula for working and setting gains by using a multimeter in a tutorial on here (scroll down to subwoofer part). Then using the subsonic filter setting part, thats where i got those frequency's above
http://www.caraudio.com/forums/amplifiers/63933-gain-setting-tutorial-42.html#post4104530


Subs are wired to 1 ohm and amp at 1000watts. square root of 1000 = 31.62v

I dont know what you mean by verified impedance at different frequency.

Your amp will virtually never see 1 ohm while playing those woofers and playing around with a dmm beyond testing continuity of your connections is worthless.

MellowHype
04-16-2014, 12:45 AM
Your amp will virtually never see 1 ohm while playing those woofers and playing around with a dmm beyond testing continuity of your connections is worthless.

So how would you recommend setting subsonic filter? or gains? I also dont understand why the amp wouldnt see 1 ohm other than resistance in the wires etc

phemps
04-16-2014, 01:19 AM
So how would you recommend setting subsonic filter? or gains? I also dont understand why the amp wouldnt see 1 ohm other than resistance in the wires etc

Becuase its not simple DC resistance and the woofers have an impedance curve. I set my subsonic at 1/3 octave or so below tuning

hispls
04-16-2014, 11:18 AM
So how would you recommend setting subsonic filter? or gains? I also dont understand why the amp wouldnt see 1 ohm other than resistance in the wires etc


What he said ^^^

MellowHype
04-16-2014, 11:43 AM
could you tell me what a 1/3 octave of 34hz would be please?



Just got my new test leads and got the same figures, now i think its to do with the test track i used. I just dragged the test track into audacity and showed clipping and the whole thing was red indicating clipping all over.

All i did was create tone, and set amplitude to 1. Is this not correct?

Only thing i can think of is that maybe i made a -3db track before, ill give that a go in while

MellowHype
04-16-2014, 05:34 PM
Ive now spoke to a car audio specialist who is kind of local, and he owns a DD-1 and will set my amp for $25.

Is that the best way for me to go about this to get the most out of my amp and subs?

MellowHype
04-16-2014, 10:00 PM
i used the -3db 60hz tone and im sure its still not right. Its only a little louder than when i had a single R on 700 watts.

Think im gonna have to take it to the person with the DD-1. Whats your guys opinions on the DD-1?

phemps
04-17-2014, 04:02 AM
could you tell me what a 1/3 octave of 34hz would be please?



Just got my new test leads and got the same figures, now i think its to do with the test track i used. I just dragged the test track into audacity and showed clipping and the whole thing was red indicating clipping all over.

All i did was create tone, and set amplitude to 1. Is this not correct?

Only thing i can think of is that maybe i made a -3db track before, ill give that a go in while

Approximately 28 HZ is 1/3 octave down. An Octave is one half, or double a frequency so and octave below 34 is 17 hz/3 is 5.66 hz. 34-6 gives you your subsonic setting. As far as the DD1 goes... I have one and they do the job

MellowHype
04-17-2014, 06:44 PM
Waiting on a reply from the person with the DD-1

In the meantime i went and put a fresh battery in my DMM and i set the volts to 32 which is like square root of 1030 watts even though my amp is only rated at tad over 1000, and it went from being like one R to quite alot louder but it made my lights dim like crazy. Also standing from the outside of the car its definitely not loud.

really hoping that the DD-1 gets alot more out of these subs, im happy to add another battery, but its just annoying if i had known the gain going from one 12 @ 700 to 2 12's @ 500 each, would have only been as much as i have seen so far i wouldnt have bothered.

MellowHype
04-19-2014, 08:53 AM
Just thought id upload a couple pics of the finish

http://i1243.photobucket.com/albums/gg557/MellowHigh/portin2_zpsef71f4d0.jpg
http://i1243.photobucket.com/albums/gg557/MellowHigh/DSC00437_zpsa36b0fa2.jpg
http://i1243.photobucket.com/albums/gg557/MellowHigh/DSC00438_zpse3b90f0f.jpg

Im now looking into a car with a boot that should get 5ft^3 in it so those Rs will perform better and then next on the list will be a 2k rms amp

hispls
04-19-2014, 09:49 AM
Have you considered just turning up the gain until you can hear distortion while playing music? How about just fiddling with your crossover settings until you're not over-driving the woofers mechanically? I can't believe you're actually considering paying someone 25$ to do something you could do in a couple minutes.

MellowHype
04-19-2014, 12:28 PM
Have you considered just turning up the gain until you can hear distortion while playing music? How about just fiddling with your crossover settings until you're not over-driving the woofers mechanically? I can't believe you're actually considering paying someone 25$ to do something you could do in a couple minutes.


Well ive set the high pass to 80 and the subsonic to around 30.

I guess i could give setting the gains by ear a go, its just i dont wanna push my amp too much and kill it. I definitely think the amp has got more than what im pushing it to.

I was wondering aswell, ive found some KnuKonceptz KLM 4 gauge thats very very cheap, and i was thinking of doing the big 3 with that, as it says its good up to 250 amps. The thing is though its CCA aswell and 4 gauge so i dont know if id be wasting my time.

hispls
04-20-2014, 02:38 AM
Well ive set the high pass to 80 and the subsonic to around 30.

I guess i could give setting the gains by ear a go, its just i dont wanna push my amp too much and kill it. I definitely think the amp has got more than what im pushing it to.

I was wondering aswell, ive found some KnuKonceptz KLM 4 gauge thats very very cheap, and i was thinking of doing the big 3 with that, as it says its good up to 250 amps. The thing is though its CCA aswell and 4 gauge so i dont know if id be wasting my time.

Assuming you fused your amp correctly and it has functioning protection circuits it's unlikely you'll break it by over-driving your subs a little

MellowHype
04-20-2014, 05:40 PM
Assuming you fused your amp correctly and it has functioning protection circuits it's unlikely you'll break it by over-driving your subs a little

i think my amp has 3 x 35 amp fuses in it, the 4 awg wire used is fused with 150 amp. Is there a chance my 100 amp alternator or low end battery could be anything to do with the lack in power? my lights dim like crazy

hispls
04-20-2014, 07:39 PM
You tuned at 30hz? Subsonic should be set @ 22 hz and 30hz tuning won't be loud. Cut a few inches off the inside of that port if you want loud.

Poor electrical won't help. It takes power to make power.

MellowHype
04-20-2014, 09:33 PM
You tuned at 30hz? Subsonic should be set @ 22 hz and 30hz tuning won't be loud. Cut a few inches off the inside of that port if you want loud.

Poor electrical won't help. It takes power to make power.

34/35 hz
And yeah i think i should get a big batt next. Possibly 2 as i read you shouldnt run 2 different make batts together