MyE28.com

I made one of these for Austin8753 as a stealth sub box install. It was soopa easy and I can make one for you too if you want one.

It's sized to fit up against the back of your rear seat with a panel to make it look like it's not even there. This is a 12" sub with a 1.25 cuft volume. I can make it for any size sub with the proper interior volume. It's sealed tight as a virgin's honeypot and has gold plated connectors. 3/4" MDF sealed with caluking on the inside. The carpet overlaps on the sides to cover the gap for a clean look. Carpet on the bottom to add some grip on your trunk carpet. I suppose I can make a ported box too if you really want it.

Of course it won't come loaded with a sub. Sized to fit under a rear strut brace. I would need the height from floor to the bottom of your brace if you have one since many are different. Room on the sides for mounting crossovers. Or I can have the box all the way over to the side and have room for amps mounted out of view. But I like under the rear seat for mounting amps.

$150 plus shipping from 97220 If you are going to 5erWest, order one now and I'll bring it.

You wouldn't have ay experience with fabricating a sub enclosure for underneath the drivers side rear seat, would you?

TucciRW wrote:You wouldn't have ay experience with fabricating a sub enclosure for underneath the drivers side rear seat, would you?

I have tried....but the angles, clearences, space restrictions are a pain in the ass to deal with. Big time pain in the ass. I know there are people htat have done it. I just don't want to deal with the hassle. Plus you wouldn't be getting the proper interior box volume to maximize the sound of your subwoofer.

Hmmm, I definitely like that and if I were to get one I'd want it ported. But as of this moment, I have no fundage.

Paul in N FL wrote:Hmmm, I definitely like that and if I were to get one I'd want it ported. But as of this moment, I have no fundage.

I agree. The sub i have is in a vented box. If theres a way can engineer a vented box (with correct chamber dimensions) i would be in.

That is cool!

rojacob wrote:

Paul in N FL wrote:Hmmm, I definitely like that and if I were to get one I'd want it ported. But as of this moment, I have no fundage.

I agree. The sub i have is in a vented box. If theres a way can engineer a vented box (with correct chamber dimensions) i would be in.

It's just a matter of finding the ported dimensions. Not a problem. I have the technology to do so. If you say do it...I will.

PM me.

I also will add that I also I cut a hole in the rear firewall to let more bass through in to the cabin. Right behind the rear armrest.

ilikemybike wrote:Plus you wouldn't be getting the proper interior box volume to maximize the sound of your subwoofer.

What's the use in installing a sub in a trunk which is sealed from the passenger compartment? For the sub to function correctly and get the bass into the passenger compartment you'll need to cut an opening into the rear bulkhead. Something about the size of the cutout needed for the ski bag option.

Just my $.02

Rich

And that's why I don't do stereo.

Nice work on the box, though I'd expect nothing less from you given your workshop!

Rich Euro M5 wrote:

ilikemybike wrote:Plus you wouldn't be getting the proper interior box volume to maximize the sound of your subwoofer.

What's the use in installing a sub in a trunk which is sealed from the passenger compartment? For the sub to function correctly and get the bass into the passenger compartment you'll need to cut an opening into the rear bulkhead. Something about the size of the cutout needed for the ski bag option.

Just my $.02

Rich

That's just what I did.

Rich Euro M5 wrote:For the sub to function correctly and get the bass into the passenger compartment you'll need to cut an opening into the rear bulkhead.

Not exactly.

The sub-100Hz stuff will pass through the bulkhead without much loss at all. And with the speaker in the same plane as the bulkhead, you may actually get low end radiating from the entire bulkhead, which could be a good thing (or could cause lots of rattling).

If you want to cut a hole into the cabin, I'd think the best choice would be to build a compound enclosure that vents into the area behind the rear armrest.

Rear seat passenger's full torso massage. Now that is one hell of a good option. I love mine.

podgorny wrote:If you want to cut a hole into the cabin, I'd think the best choice would be to build a compound enclosure that vents into the area behind the rear armrest.

Still thinking about this. Surely someone has built a system that uses the trunk as the sealed chamber and ports into the cabin.

TucciRW wrote:You wouldn't have any experience with fabricating a sub enclosure for underneath the drivers side rear seat, would you?

I've been looking at this subwoofer:

http://www.crutchfield.com/s_130SW841D/ ... D&skipvs=T

It seems to get pretty good reviews, is very shallow, and from what I've read the ideal ported box size is 0.4 cubic feet, which should be achievable under the rear seat. I just haven't designed the box yet, or bought the sub, or bought my new head unit, or my new speakers. Other than that, I'm almost there!

Trunk carpet in place. Pretty flippin' sweet!

I'ver calculated out the port length and diameter for a 12" sub tuned to 35hz. Can do if you want it.

That is the one that I installed 3 years ago in my car:



You can get it cheaper on Ebay. My box is not 100% sealed but it actually gives a pretty strong bass. I've had my sons seating in the back and had no complaints of anything hitting their behinds!

desmofan wrote:

TucciRW wrote:You wouldn't have any experience with fabricating a sub enclosure for underneath the drivers side rear seat, would you?

I've been looking at this subwoofer:

http://www.crutchfield.com/s_130SW841D/ ... D&skipvs=T

It seems to get pretty good reviews, is very shallow, and from what I've read the ideal ported box size is 0.4 cubic feet, which should be achievable under the rear seat. I just haven't designed the box yet, or bought the sub, or bought my new head unit, or my new speakers. Other than that, I'm almost there!

That's the sub member PMA has under his rear seat in a small box. I built him a box for his second sub that fits under his passenger FRONT seat. It sounded just fine.

podgorny wrote:

podgorny wrote:If you want to cut a hole into the cabin, I'd think the best choice would be to build a compound enclosure that vents into the area behind the rear armrest.

Still thinking about this. Surely someone has built a system that uses the trunk as the sealed chamber and ports into the cabin.

Since a PO cut three holes in a triangular pattern, in two different locations of the trunk bulkhead, centered on each rear seat passenger in the M5. I've given some thought to building a sub with a passive radiator, most likely built around 8" components. My idea is to cut out two openings just large enough for the sub and radiator, centered on the existing holes, and have them bolt up to a properly designed enclosure mounted on the trunk side of the bulkhead.

Rich

jimoreno wrote:That is the one that I installed 3 years ago in my car:



You can get it cheaper on Ebay. My box is not 100% sealed but it actually gives a pretty strong bass. I've had my sons seating in the back and had no complaints of anything hitting their behinds!

This is exactly what I plan on doing, except I may make it a vented box; haven't decided yet. I did find it on Ebay for $80, which is a great price. I'm thinking of buying my head unit at Crutchfield though, to thank them for all the research I've been able to do on their site, and they're price is decent.

Under the rear seat is what fiberglass is for.

Doing that in MDF is a waste of time.

ElGuappo wrote:Under the rear seat is what fiberglass is for.

Doing that in MDF is a waste of time.

Yep.

podgorny wrote:

podgorny wrote:If you want to cut a hole into the cabin, I'd think the best choice would be to build a compound enclosure that vents into the area behind the rear armrest.

Still thinking about this. Surely someone has built a system that uses the trunk as the sealed chamber and ports into the cabin.

I have a box that does JUST this for my E34...there is a guy building them for people on bf.c and r3v.

skip535i wrote:

podgorny wrote:

podgorny wrote:If you want to cut a hole into the cabin, I'd think the best choice would be to build a compound enclosure that vents into the area behind the rear armrest.

Still thinking about this. Surely someone has built a system that uses the trunk as the sealed chamber and ports into the cabin.

I have a box that does JUST this for my E34...there is a guy building them for people on bf.c and r3v.

For twice my price.

Your box isn't ported...or did I miss something?

skip535i wrote:Your box isn't ported...or did I miss something?

Imma gonna say the latter:

ilikemybike wrote:

rojacob wrote:

Paul in N FL wrote:Hmmm, I definitely like that and if I were to get one I'd want it ported. But as of this moment, I have no fundage.

I agree. The sub i have is in a vented box. If theres a way can engineer a vented box (with correct chamber dimensions) i would be in.

It's just a matter of finding the ported dimensions. Not a problem. I have the technology to do so. If you say do it...I will.

PM me.

I also will add that I also I cut a hole in the rear firewall to let more bass through in to the cabin. Right behind the rear armrest.

Have you gotten it weighed for shipping costs? I want to find out the Total price so I can go scavenging for money.

PMing- very interested. I have an amp in the way, then need another amp for the sub- you say there are room for both of them under the rear seat? I haven't even looked- I know, lame.

I think I like the sealed box, and yes, a thin piece of sheet metal isn't going to slow down anything under 100hz, but then again, since my other speakers stop at 200hz, that means we NEED that 100-200, so the hole might be needed, and the sub crossed super high.

That is of course, for the full-range crowd. Most stereos I hear these days are only concerned with woofs and tweets. My $.02

Is the M5 trunk any different than the non M5 trunk in that area? Does the battery box get in the way?

ilikemybike wrote:Is the M5 trunk any different than the non M5 trunk in that area? Does the battery box get in the way?

The only difference in that area is that the carpet is a cut pile instead of the style you're using.

skip535i wrote:

podgorny wrote:

podgorny wrote:If you want to cut a hole into the cabin, I'd think the best choice would be to build a compound enclosure that vents into the area behind the rear armrest.

Still thinking about this. Surely someone has built a system that uses the trunk as the sealed chamber and ports into the cabin.

I have a box that does JUST this for my E34...there is a guy building them for people on bf.c and r3v.

For an E28 box, Luke charges $250, you have to have at least 4 orders in to make it worth his while and they wouldn't be ready 'til well into summer. I'm not hating on the guy at all; he makes a sweet box, but I think this is a better solution to my needs. Plus, I like supporting a local business!

Jeff, thanks again!