# SPL box build questions



## IAWarden89 (Oct 4, 2010)

So I am building a box for a 12 inch IA warden. I do not have an amp for it yet. The amp I am testing it on will be a Audison VRX 1.500 until it is sold. The poll above is my trying to figure out what type of box to build for the best SPL numbers. I do not care about SQ with this box. I will build the box, but if it goes to a Aero port I will have a few questions and a 4th or 6th order I might need a little help with the design(as I haven't done one yet).


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## Oliver (Jun 25, 2007)

This is from 2009 , Can you look at the picture and build one similar to it?

http://www.diymobileaudio.com/forum/diyma-spl-forum/71693-156-1-db-one-sub-no-wall-12v.html

Box specifications in thread ^^^



> It's about* 3.5 cubes with 96 in^2*
> 
> The top PVC piece gains 0.1 dB
> 
> It has corner rounds inside but it's not kerfed wood.


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## IAWarden89 (Oct 4, 2010)

So try 2.5 cubic feet with how many inches of port? The sub he used was a 15 I have a 12. Will the port area be different?


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## Oliver (Jun 25, 2007)

NO , I didn't mean for you to make the box the same size as for the 15 

what i was getting at, is this is an SPL box , you just need to get some batteries and amplifiers and build a suitable box to make the biggest possible numbers.


Here is what I can find for info on your model: Incriminator Audio: No Chrome, No Carbon Fiber, No BS! Period

Sub Diameter 12 3/8 inches 
Mounting 11 1/8 inches
Mounting Depth 8 1/4 inches 
Driver Displacement .21 cubic ft
Power 2500 Wrms / 5000 Peak



> Features inlude:
> 
> • 8 Spoke Black Cast Basket
> • 3" 8 layer Flat Aluminum Voice Coil
> ...




This is how to find out about your sub as far as a box size >> Incriminator Audio: No Chrome, No Carbon Fiber, No BS! Period


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## IAWarden89 (Oct 4, 2010)

I have talked to them in about 20 different emails. I get bunches of different answers. It goes from 1.8 cubic feet all the way to 3 cubic feet and then mixed answers to port area as well. Hence why I was asking about the type of box to build.


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## Volenti (Feb 17, 2010)

With no driver parameters it makes it difficult to advise on an optimum enclosure, as a starting point 2.5-3 cuft is a reasonable size with as much port area as you can fit, start at half the drivers SD and go up from there.

Without parameters anything more complex is basically out of the question.


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## IAWarden89 (Oct 4, 2010)

RE: 2.22 ohms
FS: 47.83 Hz
Qes: 0.36
Qms: 6.43
Qts: 0.34
Le: 2.0 mH
Vas: 11.97 L
BL: 24.86 NA
Cms: 33.219 uM/N (super stiff)
Mms: 333 grams
Sens: 87.45 1w/1m
BL^2/RE: 278 (nice!)

A standard 9" diameter SPL motor with 8-layer 3" coil typically has 150-200 BL^2/RE... so this thing is strong.


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## Volenti (Feb 17, 2010)

Ahh, very nice, both ported and BP appear to max out about the same, so ported is the simpler option, 3cuft tuned to 55hz, 70sqin of port area 13'' long would be a reasonable starting point.


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## IAWarden89 (Oct 4, 2010)

Another fun fact. My cars rez freq is 47hz.


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## Volenti (Feb 17, 2010)

IAWarden89 said:


> Another fun fact. My cars rez freq is 47hz.


This is something you'll have to expriment with , the last time I used a variable port on an spl box (happened to be a 4th order BP but same principle applies) I got a higher spl with the higher tuning frequency even though the car's res frequency was 48hz and the final tuning of the bp ended up at 60hz, ie; burp frequency was 48hz, tuning was 60hz, and that was considerably louder (was a long time ago, couple of db louder I recall) than the 48hz tuning.

Same car, different enclosure (tapped horn) and the highest burp frequency was the frequency the horn was tuned to (65hz) basically ignoring the res frequency of the car.


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## IAWarden89 (Oct 4, 2010)

So try a slot port with it tuned at 55hz, build it so i can take the top of and add in a different sized L part for tuning adjustment. Then once I figure that out Ill build a box that will be my actual box based off that one.


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## IAWarden89 (Oct 4, 2010)

I have a friend putting a design together for a Aero port. We are going to try to do a single 6 inch tuned to 42hz. I think that should do pretty good.


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## cubdenno (Nov 10, 2007)

I would say not enough port area. port is designed around the woofers SD, xmax and the tuning frequency.

Those "rules of thumb" are not accurate.

This calculator will get you close.
PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES

They give you a minimum for area. Now its going to be huge. So reduce it to something you can live with while keeping port compression down.


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## Oliver (Jun 25, 2007)

IAWarden89,

How loud does it get ? what box did you build ?


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## IAWarden89 (Oct 4, 2010)

I ended up getting rid of the sub and now have a DC Audio LVL 5 SPL 10. I don't currently have an amp so I am not really in a rush to build a box for it. I am waiting for the new Crescendo BC5500 to be released.


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## Oliver (Jun 25, 2007)

http://http://www.youtube.com/watch?v=IVhoFjIEI1c&feature=related




> The Atomic puts out about 5.2kw @ 1 ohm on 14.4v


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## mcbuggin (Mar 6, 2011)

not sure if it helps or not but it it were me I would use external aeros in a small enclosure and slowly cut down the streight part of the port till I found the sweet spot. This is cause i'm lazy and wouldn't want to build 100 boxes to find out what works best. Let us know how that lvl5 works saw and heard a 15 in a horn ran off a RD 5750. Not only was it loud but it sounded pretty good for a SPL sub


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## Streetbeat Customz (Mar 19, 2011)

Port as big as possible to start, then cut it down until you find the peak.


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## SkizeR (Apr 19, 2011)

i design boxes for a smalllll price. pm me if interested


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## area51 (Sep 27, 2009)

If you are going to build a box for strictly just SPL numbers then an aero port is the way to go. It lets you tune till you find the the right freq. you are not locked into the build like a slot.


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## XtremeRevolution (Dec 3, 2010)

See the link in my signature. 

X2 on the aero/flared ports. You can buy them from partsexpress.com.

Sent from my HTC Awesome using Tapatalk


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