# Gauging interest for Custom compact sub box



## billseast (Feb 5, 2013)

I'm trying to see if there is interest in custom made compact sub box. I build boxes that take up very little trunk space but interior volume is 1 cubic foot. I always shoot for 1 cubic foot because it is a great size for most 10" subs and 12" subs. I have been doing fiberglass boxes since 2006. I started with the GTO since there trunk is so small to start with. I build boxes for the Camaro ,Charger ,Challenger, 300, Tundra, GTO, G6 and adding more models. If you do a google search for Intense auto works you will find feed back from LS1GTO.com and see more pics of my work. My website is getting redesigned right now so there is nothing on it yet. If i get enough interest i will sign up as a sponsor for this site. I always have my customers pay using Paypal since it is the most trusted way to send money.


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## brian v (Dec 25, 2011)

I hope you sell a ton ,and get rich so you can employ a team to assemble those in the US so we can all have them .
best of luck Bro.


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## blk88verde (Apr 30, 2011)

I might be interested. I have an 04 GTO. Those boxes look nice.


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## billseast (Feb 5, 2013)

Got the box stared but it looks like there will only be room for a 10" sub on the driver side


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## XtremeRevolution (Jan 19, 2012)

billseast said:


> Got the box stared but it looks like there will only be room for a 10" sub on the driver side


How much internal volume will be available exactly? 

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## billseast (Feb 5, 2013)

XtremeRevolution said:


> How much internal volume will be available exactly?
> 
> Sent from my SGH-T999 using AutoGuide App


I will know in a couple days when I get the box complete.


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## NB99Z (Jan 26, 2013)

Those look nice. I'm trying to stay away from putting a sub in the trunk. But a nice out of the way side box might change my mind.


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## brian v (Dec 25, 2011)

I am sweating this one out for a little while longer ,this could shape up nicely when more interest with your concept appears ...
although established in it's origins of the heavily modded custom auto world .Personally I have always liked this Idea utilized with a sub..//


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## XtremeRevolution (Jan 19, 2012)

The challenge will be making the fiberglass walls dead enough to not resonate at frequencies up to 125hz, and finding a sub that actually sounds good in the space and depth requirements. Manufacturer recommended specs are designed with compromise for size in mind, with sound quality being a second priority. A good sound absorption pad will be needed to absorb higher frequency harmonics to reduce wall resonance and backwave distortion.

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## brian v (Dec 25, 2011)

I totally agree with those ideas given the restraints of the allowable space of a fixed enclosure .
so if we do the math considering resonance and accounting for this issue a little more depth , May attribute to better SQ.


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## XtremeRevolution (Jan 19, 2012)

brian v said:


> I totally agree with those ideas given the restraints of the allowable space of a fixed enclosure .
> so if we do the math considering resonance and accounting for this issue a little more depth , May attribute to better SQ.


I have yet to see someone calculate expected resonance or distortion from backwaves in sub boxes. Too many variables. 

One would need to have an idea of what sub they want to use before they go about building a box if SQ is a priority. Otherwise, space savings and concealment becomes the primary advantage. 

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## brian v (Dec 25, 2011)

Hence your question how much allowable volume/ you have a given dimensions to your designs to help you when designing enclosures, and I am sure that you consider the variables to the best of your abilities when factoring SQ in the build ,we are throwing theories with tests and trials .we can theorize with established acceptable tolerances when known.I think I recall you ask for 1 square foot of depth for acceptable back compression,for distortion. We are trying to help interested parties..


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## billseast (Feb 5, 2013)

I get the Fiberglass thick enoug that it doesn't flex and it gets strong enough to handle the force of the woffer and they do sound good. The boxes that I do get close to one cubic foot so most 10s and 12s work in a one cubic foot box. The boxes are not for a total audio nut that wants perfect sound they are made to give the customer some good low end sound not perfect low end sound.


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## brian v (Dec 25, 2011)

Will a duel coil 8 inch by polk give any more sound quality ,or perform with out the back wave distortion?
Have you built any down firing enclosures ? Experiment/


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## XtremeRevolution (Jan 19, 2012)

billseast said:


> I get the Fiberglass thick enoug that it doesn't flex and it gets strong enough to handle the force of the woffer and they do sound good. The boxes that I do get close to one cubic foot so most 10s and 12s work in a one cubic foot box. The boxes are not for a total audio nut that wants perfect sound they are made to give the customer some good low end sound not perfect low end sound.


It's not a matter of strength with regard to holding the pressure created by the woofer; it's a matter of resonance created by the sound waves and harmonics. Extremely strong materials will still resonate. I will admit, this is an issue of high end sound quality and not something that most people wanting a bit more oomph will really care about. 

However, internal volume is an entirely different story. You don't have to be a total audio nut to be able to tell the difference between a good sounding box and a boomy sounding box. 

Exhibit A: Dayton HF 10
Dayton Audio RSS265HF-4 10" Reference HF Subwoofer 4 Ohm 295-460

This sub is a 10" sub that will NOT sound good in 1 cubic foot of space. In fact, it requires at least 1.25 cubic feet to sound decent. 1.3 cubic feet is the best compromise between size and sound quality. 

Exhibit B: Infinity 1262W
Infinity 1262w Reference Series 12" subwoofer with dual 4-ohm voice coils at Crutchfield.com

This sub requires 1.5 cubic feet.


I only used those two examples to show that you cannot make a blanket statement saying that most subs of two differnet sizes will work well in one specific internal volume. Internal space makes a huge difference in how a sub sounds. While the 10" Alpine Type-R will sound great in 1 cubic foot of space, the 12" Alpine Type-R will require at least 1.2 cubic feet. Like I said before, most manufacturers spec MUCH too small of a box simply for convenience purposes; not because the sub will actually sound good in that size. Most people wouldn't want to buy a 1.5.2.0 cubic foot box for a single 12" sub. 

I'm not trying to make your job more difficult here, so don't take this the wrong way. In fact, I offer to model subs for people for free, so if you want me to model any particular sub in 1 cubic foot of space to tell you if it will sound good or not, I'd be more than happy to do so. However, I don't like seeing people spend their hard earned money on a sub that isn't suitable for a given box when they could have picked a sub that actually worked well to begin with.


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## XtremeRevolution (Jan 19, 2012)

brian v said:


> Will a duel coil 8 inch by polk give any more sound quality ,or perform with out the back wave distortion?
> Have you built any down firing enclosures ? Experiment/


Who are you asking?

If you're asking, no subwoofer is immune to back wave distortion. Here's the concept behind it. 

A subwoofer produces sound waves from the front of the cone in addition to the back. What you end up with is two waves that are completely out of phase with each other. If you were to play a subwoofer at low frequencies in free air, the two waves would cancel themselves out and you would not hear any bass. Inside the box, most bass sound waves will simply act as pressure on the box as the waves are far too large, but harmonic frequencies played by the subwoofer will produce sound that will bounce off of the inner walls of the enclosure and hit the cone again. The end result will be a sound wave hitting the cone, thus producing a sound out of the front of the cone that was not signaled by the amplifier. Any time a speaker creates a sound that is not directly signaled by the amplifier, it is considered distortion. 

If you have sound absorption material inside a box, it helps absorb those rear waves to reduce the amplitude of this distortion.

I have not built down firing enclosures for car audio as I have not experienced positive results in car audio. I have experimented with other subwoofers and discovered that the best compromise of output and practicality when using a rectangular box will come with placing the sub(s) as close to the back seats as possible, facing the rear of the car. Custom enclosures such as the one billseast is offering produce great results due to boundary loading.


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## rpcraft (Jan 12, 2013)

There's some good info being shared here but it's important to note that some folks are going to go the path of least resistance and for them this may be a a great solution. Especially if they want a small box that is out of the way and occupies as little space as possible in the trunk. Sure there will probably be a sacrifice in SQ or db level, but that is the sacrifice that gets made when you start looking for compact ways to hide what often times takes up a larger amount of space when done to proper (or exact) specifications. I think the factor that will offer the greatest divider for some will be the price point for this solution. I know what I would be willing to pay for convenience but I also know what I would be willing to pay for quality. He'll just have to account for the fact that if it isn't going to be tolerable (in terms of internal volume) then anyone could go find a prefabbed single sub box (yeah still junk) from most brick and mortars for around 20 - 30 bucks and it would serve as a basic platform to amplify bass with similar qualities.


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## XtremeRevolution (Jan 19, 2012)

rpcraft said:


> There's some good info being shared here but it's important to note that some folks are going to go the path of least resistance and for them this may be a a great solution. Especially if they want a small box that is out of the way and occupies as little space as possible in the trunk. Sure there will probably be a sacrifice in SQ or db level, but that is the sacrifice that gets made when you start looking for compact ways to hide what often times takes up a larger amount of space when done to proper (or exact) specifications. I think the factor that will offer the greatest divider for some will be the price point for this solution. I know what I would be willing to pay for convenience but I also know what I would be willing to pay for quality. He'll just have to account for the fact that if it isn't going to be tolerable (in terms of internal volume) then anyone could go find a prefabbed single sub box (yeah still junk) from most brick and mortars for around 20 - 30 bucks and it would serve as a basic platform to amplify bass with similar qualities.


To note, I didn't say there are no subs in existence that will sound good in 1 cubic foot. I simply pointed out that the statement claiming that most subs will sound "good" in 1 cubic foot is incorrect. There are at least a dozen affordable subwoofers I can recommend that will sound great in one of his 1 cubic foot fiberglass boxes. The key is knowing which subwoofers those are.


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## rpcraft (Jan 12, 2013)

True indeed. I wasn't pointing out anything wrong with your facts or philosophy. We all just know some guys out there want it cheap and easy, lol..

:signs015:


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## brian v (Dec 25, 2011)

Now you have taught me a few things X. I knew you had good Ideas up there.
Now if bill,has his thinking cap on he will learn a few things.


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## billseast (Feb 5, 2013)

http://www.cruzetalk.com/forum/4009-xtremerevolution.html XtremeRevolution sure knows his audio. I also get the fact that not all sub will work in the type of enclosures that i build. I have had looks of poeple that want to but the wrong sub in to small of boxes and i tell them not to do it all the time. The little boxes that i'm building are for being able to just mock it up one time in the car then i can make copy's real easy. I can make almost any box that people would want and get real custom but they arent looking for the BEST sound. The real custom looking stuff is just for showing off. Its all about the look not the sound. Just like this box i built for the Dodge magnum in 2006. It was for the sema show just needed to look good but it did sound pretty good.


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## brian v (Dec 25, 2011)

That is sweet . Now improve on this Idea for us .


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## XtremeRevolution (Jan 19, 2012)

billseast said:


> XtremeRevolution sure knows his audio. I also get the fact that not all sub will work in the type of enclosures that i build. I have had looks of poeple that want to but the wrong sub in to small of boxes and i tell them not to do it all the time. The little boxes that i'm building are for being able to just mock it up one time in the car then i can make copy's real easy. I can make almost any box that people would want and get real custom but they arent looking for the BEST sound. The real custom looking stuff is just for showing off. Its all about the look not the sound. Just like this box i built for the Dodge magnum in 2006. It was for the sema show just needed to look good but it did sound pretty good.


If you want to play it safe as far as subs go, here's a list of subs I can think of off the top of my head that I know will sound great in 1 cubic foot:

Alpine 10" Type-R
Image Dynamics IDQ10 V3
Image Dynamics IDQ12 V2 (if you can find one)
TC Sounds Epic 10
Dayton HO 12 DVC


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## billseast (Feb 5, 2013)

brian v said:


> That is sweet . Now improve on this Idea for us .


That box took about 50 man hours.


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## billseast (Feb 5, 2013)

Here is a pic of a box i just finished for a local guy for his GTO.


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## XtremeRevolution (Jan 19, 2012)

That looks great! If I might make a suggestion though, if you can attach some large MDF rings to create a flush mount of those subs, it would look all that much better. Ever since I started building flush mounts into all of my boxes, I haven't been able to look at a standard box the same way again. It's just so much cleaner. 

Awesome work though.


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## billseast (Feb 5, 2013)

XtremeRevolution said:


> That looks great! If I might make a suggestion though, if you can attach some large MDF rings to create a flush mount of those subs, it would look all that much better. Ever since I started building flush mounts into all of my boxes, I haven't been able to look at a standard box the same way again. It's just so much cleaner.
> 
> Awesome work though.


i used 1/2 rings the 3/4 were to big


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## XtremeRevolution (Jan 19, 2012)

billseast said:


> i used 1/2 rings the 3/4 were to big


Too big for the sub? A router with a 45 degree chamfer bit will solve that problem. Works perfectly with my boxes. 

I've noticed sub flange thickness varies greatly. My IDMax has a 3/4" flange, the V3 IDQ subs have a 5/8" flange, and the V2 IDQ subs have a 1/2" flange. For anything between 3/4" and 1/2", I just route a chamfer over it and it ends up looking great.

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## larry0071 (Dec 1, 2012)

Are you putting together a user friendly package with factory integration harness, sub, box and amp? Or, is this sub and box and the customer needs to get through the challenge of getting the signal and amplifying it?

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## rpcraft (Jan 12, 2013)

sub box only, thus all the previous discussion about YOU having to ensure your subs meet up with the internal volume of the box and etc....


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## XtremeRevolution (Jan 19, 2012)

larry0071 said:


> Are you putting together a user friendly package with factory integration harness, sub, box and amp? Or, is this sub and box and the customer needs to get through the challenge of getting the signal and amplifying it?
> 
> Sent from AutoGuide.com Free App


The only factory integration harness that's available is still something you'd have to buy separately and run wires for, and even if he or I provided you with the wiring, you'd still have to run it.


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## billseast (Feb 5, 2013)

larry0071 said:


> Are you putting together a user friendly package with factory integration harness, sub, box and amp? Or, is this sub and box and the customer needs to get through the challenge of getting the signal and amplifying it?
> 
> Sent from AutoGuide.com Free App


I can supply the amps and subs also just not the adapter. But I can call tomorrow to see if I can get them.


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