Been out of the game a LONG time, have a great idea, feel overwhelmed on where to start with box design

[TexRob]

I used to be into car audio in the mid 90s.  When I was big into car audio and working at a shop doing installs and sales, a little Autotek amp that was tiny was a big deal, Svaard came out of nowhere and was the first real "no name" brand that came out of nowhere and took on the scene that I can remember, and I think that has continued since?

 

I've loosely followed stuff since, but have only done aftermarket head units and drop in speaker replacements if anything, in my wife and my cars over the past couple of decades.  I have a killer home theater setup that I kind of nailed.  I was enjoying it recently, and it reminded me of how I used to always have that level of audio in my car.

 

So, my last really unique install was an 8" sub that replaced the armrest in the back seat of my car at the time.  That solo 8 in a tiny box did great, but I never threw a lot of power at it, and I think the box was always too small (even though I specifically found a sub that could work in a tiny box).  I knew a guy who had a car with subs that fired at your back, behind the seat that always hit so hard, and provided that kick I really love.  So, fast forward to today, I drive a 2011 WRX sedan.  I've decided I want to build a box that basically turns the rear footwell into a big box.  It doesn't all have to be a chamber, but it will be topped with a piece that fits up against the rear seat surface.  How would you all approach this?  Design the box to fit the space, then worry about finalizing the interior space via some other means?  How would that look?  is there a modern solution to this?  I did this as a teen, so while I have experience in it, I guarantee you I didn't do stuff great back then.  How would you all port something like this?  I'll upload some designs at some point, but to get this started, the base would be roughly 18"x8", so I'm wondering if porting from the side of the box would work since that's my longest side?  The speakers would be facing the seat back, and I was thinking the ports facing inwards towards the centerline of the car.  I'd probably cover this area and connect the two side across the hump in the middle, but port into the open air below that.  Hopefully this makes sense.

 

What do you all think about this design?  I'll probably hide the amp under a seat or somewhere on the box where it's not seen if that works out.  Realistically I won't be starting this for a while, I think I have a blown head gasket, so, priorities.  This will definitely be budget, and flash means nothing to me as I will be trying to make it pretty stealth as far as the final look (carpet the box to blend in with the seats, etc.  I've done some 8" sub research, and it really just seems to depend on how much money and wattage you want to spend.  Right now, I have no subs in my car, so, lets be realistic.  I'm thinking like $500-700 for subs and amp is what I'd like to spend, not counting wood, carpet, wiring, etc.  So, any ideas you all have for subs and amp, or even different size subs, etc.  I've heard about some 6.5" subs that get low apparently?

[pnutz37]

20 hours ago, TexRob said:

I used to be into car audio in the mid 90s.  When I was big into car audio and working at a shop doing installs and sales, a little Autotek amp that was tiny was a big deal, Svaard came out of nowhere and was the first real "no name" brand that came out of nowhere and took on the scene that I can remember, and I think that has continued since?

 

I've loosely followed stuff since, but have only done aftermarket head units and drop in speaker replacements if anything, in my wife and my cars over the past couple of decades.  I have a killer home theater setup that I kind of nailed.  I was enjoying it recently, and it reminded me of how I used to always have that level of audio in my car.

 

So, my last really unique install was an 8" sub that replaced the armrest in the back seat of my car at the time.  That solo 8 in a tiny box did great, but I never threw a lot of power at it, and I think the box was always too small (even though I specifically found a sub that could work in a tiny box).  I knew a guy who had a car with subs that fired at your back, behind the seat that always hit so hard, and provided that kick I really love.  So, fast forward to today, I drive a 2011 WRX sedan.  I've decided I want to build a box that basically turns the rear footwell into a big box.  It doesn't all have to be a chamber, but it will be topped with a piece that fits up against the rear seat surface.  How would you all approach this?  Design the box to fit the space, then worry about finalizing the interior space via some other means?  How would that look?  is there a modern solution to this?  I did this as a teen, so while I have experience in it, I guarantee you I didn't do stuff great back then.  How would you all port something like this?  I'll upload some designs at some point, but to get this started, the base would be roughly 18"x8", so I'm wondering if porting from the side of the box would work since that's my longest side?  The speakers would be facing the seat back, and I was thinking the ports facing inwards towards the centerline of the car.  I'd probably cover this area and connect the two side across the hump in the middle, but port into the open air below that.  Hopefully this makes sense.

 

What do you all think about this design?  I'll probably hide the amp under a seat or somewhere on the box where it's not seen if that works out.  Realistically I won't be starting this for a while, I think I have a blown head gasket, so, priorities.  This will definitely be budget, and flash means nothing to me as I will be trying to make it pretty stealth as far as the final look (carpet the box to blend in with the seats, etc.  I've done some 8" sub research, and it really just seems to depend on how much money and wattage you want to spend.  Right now, I have no subs in my car, so, lets be realistic.  I'm thinking like $500-700 for subs and amp is what I'd like to spend, not counting wood, carpet, wiring, etc.  So, any ideas you all have for subs and amp, or even different size subs, etc.  I've heard about some 6.5" subs that get low apparently?

Welcome back into the bass game! The equipment that is available today compared to back then is far superior and should be able to fit within your budget.

 

The first thing I would ask myself is what do I like to listen to. Do I want all around musicality? Lows? A bit of both?

 

The next thing I would try and figure out is how much net area I have available for my enclosure. This will dictate the direction that you go for the subwoofer. If you only have 1 cubic ft space, chances are you're going with a smaller woofer. Most subwoofers can get low but that's all enclosure design. When you know how much space you have you can determine if you want to go sealed, ported or into another type of enclosure.

 

You'll want to make sure you get a enclosure designed for your subwoofer and what tuning you'd like. Don't go cookie cutter box. They will work but won't be exactly what you want. 

 

I had a dual 8" set up tuned to 32hz and it was pretty amazing. I'm sure you could make something work with smaller woofers.

[TexRob]

4 hours ago, pnutz37 said:

Welcome back into the bass game! The equipment that is available today compared to back then is far superior and should be able to fit within your budget.

 

The first thing I would ask myself is what do I like to listen to. Do I want all around musicality? Lows? A bit of both?

 

The next thing I would try and figure out is how much net area I have available for my enclosure. This will dictate the direction that you go for the subwoofer. If you only have 1 cubic ft space, chances are you're going with a smaller woofer. Most subwoofers can get low but that's all enclosure design. When you know how much space you have you can determine if you want to go sealed, ported or into another type of enclosure.

 

You'll want to make sure you get a enclosure designed for your subwoofer and what tuning you'd like. Don't go cookie cutter box. They will work but won't be exactly what you want. 

 

I had a dual 8" set up tuned to 32hz and it was pretty amazing. I'm sure you could make something work with smaller woofers.

 

I like to get low, but like I said, lets be realistic, I currently have zero lows in my car.  What you describe in your final line is where I'm at.  I would love to tune these for 30-40hz, so I can get lowish, but still hit hard and fast due to the cone size.  I will likely operate it at lower volumes 90% of the time, just being realistic.  So, performance at a mid volume is important if that is something to think about?  That's probably more of a gain adjustment type thing, but figured I'd mention it.  What I mainly want to gain is a full range of sound for normal listening, and the ability to push that to something more on occasion.

 

The bulk of the space is something like 18x8x10, with the 8 being the depth and something to consider.  I think it's plenty for a lot of 8s, even ported or vented, even with what I'll lose to the wood thickness.

 

So, given all of that, any brands I should short list for subs or amps?  I like researching stuff, so any names you wanna toss out I can dig up info on.  Any stand out budget brands right now for either?

 

EDIT:  Worth noting I have a 130 watt CO2 laser cutter/engraving table, along with tons of woodworking equipment, and a moderate 3D modeling ability

[Joe X]

Sub boxes go in the trunk generally in a sedan, that's the best possible location for it.

[pnutz37]

2 hours ago, TexRob said:

 

I like to get low, but like I said, lets be realistic, I currently have zero lows in my car.  What you describe in your final line is where I'm at.  I would love to tune these for 30-40hz, so I can get lowish, but still hit hard and fast due to the cone size.  I will likely operate it at lower volumes 90% of the time, just being realistic.  So, performance at a mid volume is important if that is something to think about?  That's probably more of a gain adjustment type thing, but figured I'd mention it.  What I mainly want to gain is a full range of sound for normal listening, and the ability to push that to something more on occasion.

 

The bulk of the space is something like 18x8x10, with the 8 being the depth and something to consider.  I think it's plenty for a lot of 8s, even ported or vented, even with what I'll lose to the wood thickness.

 

So, given all of that, any brands I should short list for subs or amps?  I like researching stuff, so any names you wanna toss out I can dig up info on.  Any stand out budget brands right now for either?

 

EDIT:  Worth noting I have a 130 watt CO2 laser cutter/engraving table, along with tons of woodworking equipment, and a moderate 3D modeling ability

Personally I'd tune between 32-34. It will get down to about 26-28 nicely and still do well up to 45-50 hz (Depending on where you have your cutoff set at). 

 

Regarding mid volume and upper volume limits would depend on what you are running for the front stage of your set up (Tweeter, mid range, mid bass). Too much power to the subs will drown out anything up front. This could be a good or bad thing. The amount of space that you are listing seems quite small and really limits the subwoofer choices and the amount of output you will get. I agree with JoeX a trunk build will be ideal and gives you the room for a decent sized enclosure backed up with a decent power amplifier.

 

For types of subs there are many. For your budget range of $500-700. I'd say go with brazillian board amp. They tend to be cheaper but still put out good power. For subs that's a tough one. If you are sticking with the space you have given, then your only real option is to go with a slim subwoofer but that limits your power handling. If you go with a trunk build, there are many options to choose from that are between $200-250 (each) and have decent power handling of 500-1000 watts rms .