I've posted one thread similar to this one once before, But I felt the need to make one a little more clear. I own a Pontiac Grand Am. One of the worst vehicles to work with when it comes to car audio installs due to very limited room. I got an idea the other day sitting in the front seat looking back at my folded down back seats. I figured.. what if I took the open area where my seats fold down leading to my trunk area, put up one peice of 3/4 or so MDF across that opening, cutting a opening in it for the 18" BTL and another for a port that's tuned to 30-35 hz and using my entire trunk area as the enclosure, without the need to build an enitre box. Since there is not enough room in my trunk to build a logical box for an 18", this seemed like a pretty genius idea. I'd of course be covering the entire lining of the trunk with DynoMat/SecondSkin (some sort of dampener). So my question is, would this be a good idea? Or would I be making myself look like a complete idiot? Like I said, I've never seen this done so I don't know if it's logical or not. Any professional advice or suggestions would be GREATLY appreciated.

I will be taking pictures later today to post on this thread to help get the idea across a little clearer.

Thanks in advance guys!

-Shag

I've posted one thread similar to this one once before, But I felt the need to make one a little more clear. I own a Pontiac Grand Am. One of the worst vehicles to work with when it comes to car audio installs due to very limited room. I got an idea the other day sitting in the front seat looking back at my folded down back seats. I figured.. what if I took the open area where my seats fold down leading to my trunk area, put up one peice of 3/4 or so MDF across that opening, cutting a opening in it for the 18" BTL and another for a port that's tuned to 30-35 hz and using my entire trunk area as the enclosure, without the need to build an enitre box. Since there is not enough room in my trunk to build a logical box for an 18", this seemed like a pretty genius idea. I'd of course be covering the entire lining of the trunk with DynoMat/SecondSkin (some sort of dampener). So my question is, would this be a good idea? Or would I be making myself look like a complete idiot? Like I said, I've never seen this done so I don't know if it's logical or not. Any professional advice or suggestions would be GREATLY appreciated.

I will be taking pictures later today to post on this thread to help get the idea across a little clearer.

Thanks in advance guys!

-Shag

Unless your trunk is completely sealed like a box would be, (besides the port) and made of MDF, I don't think it would work.

Such enclosures are called infinite baffle enclosures.

Fi makes the IB3, which is built for such applications.

You need an enclosure to port. This requires either no leaks or that you compensate for them. It would be far from trivial to compensate as your trunk is going to be really leaky.

So your choices are either build a ported enclosure and put it in your trunk, or change what woofer you will be running.

You need an enclosure to port. This requires either no leaks or that you compensate for them. It would be far from trivial to compensate as your trunk is going to be really leaky.

So your choices are either build a ported enclosure and put it in your trunk, or change what woofer you will be running.

Well I'm REALLY looking into the 18" BTL.. Have all the electrical and everything done, just need the enclosure and sub. Can you think of any ways to make this idea a reality? It's about the only way I can think of to have a big enough enclosure for the 18" without taking out my back seats. I can seal the trunk as much as I possible can with it still be functional.

You need an enclosure to port. This requires either no leaks or that you compensate for them. It would be far from trivial to compensate as your trunk is going to be really leaky.

So your choices are either build a ported enclosure and put it in your trunk, or change what woofer you will be running.

Well I'm REALLY looking into the 18" BTL.. Have all the electrical and everything done, just need the enclosure and sub. Can you think of any ways to make this idea a reality? It's about the only way I can think of to have a big enough enclosure for the 18" without taking out my back seats. I can seal the trunk as much as I possible can with it still be functional.

You REALLY need to figure out your enclosure before sub shopping. If you can't fit a box for an 18" BTL then you shouldn't run it. Sealing & functional aren't going to happen.

Well I suppose that if you don't need a back seat at all you can build an enclosure that takes up everything in the back of your car right up to your front seats.

Otherwise run two smaller subs. You can still get plenty of output with less enclosure space.

Well I suppose that if you don't need a back seat at all you can build an enclosure that takes up everything in the back of your car right up to your front seats.

Otherwise run two smaller subs. You can still get plenty of output with less enclosure space.

I need my back seats, and I don't have a budget for 2 subs.

You could seal your trunk lid, then fiberglass the entire inside of your trunk. This would make the trunk lid useless, but you could lay in there and put a few layers of 'glass and mat.

This would be only if you never planned on using your trunk again, so I would try to construct a box inside your trunk- like cut pieces then assemble inside the trunk.

build a box in the trunk as you would a wall, built inside the trunk

I've got to get the pics from my lil bro.... My lil bro put an 18 SSD into the trunk of his 08 Grand Prix.... we built the front of the enclosure like you were mentioning but build the rest of the enclosure into the trunk of the car, it will be a ROYAL PITA to ever get out and he only had enough trunk space left to mount the amp..... but it wurkz GREAT!!

Takes alot of work and some enginuity to pull it off, but it's doable.... I would imagine the trunk of that Grand Am isn't that much smaller than his..... it should be doable.....

I think you should just stick with a 15" if you have the room for that. You won't notice that big of a difference between the 15 and 18. Hell, with that sub most people will think you have two 18s in the back anyways.

I don't see why you couldn't get some sort of thick weather stripping and make it so the trunk is air tight. Make sure everyhole is filled with expanding foam and deadened over too.

To test if it's air tight all you have to do is pour soapy water on the trunk lid and let her rip, if you see a bunch of bubbles then you might have problems.

I would also double the baffle aswell because if you did run it IB/ported it will get lower than a mother.

A question that should have been asked first is how much power are you using too. If you can free air a BTL with 1000 watts then I don't see why you could use 1500-2000 cautiously.

I am only saying this because you already have the sub and you seem like you want to do this.

Drew

Edited December 18, 200915 yr by fearof85

The way you get the best sounding bass is a solid enclosure.

The means lots of bracing and rigidity. You will never accomplish that while using a trunk as an enclosure. I don't care how much deadener and fiberglass you use, it will never work as well as a traditional enclosure. Unless of course you're willing to destroy your trunk permanently.

I've got to get the pics from my lil bro.... My lil bro put an 18 SSD into the trunk of his 08 Grand Prix.... we built the front of the enclosure like you were mentioning but build the rest of the enclosure into the trunk of the car, it will be a ROYAL PITA to ever get out and he only had enough trunk space left to mount the amp..... but it wurkz GREAT!!

Takes alot of work and some enginuity to pull it off, but it's doable.... I would imagine the trunk of that Grand Am isn't that much smaller than his..... it should be doable.....

Hey man if you can get me some pictures of that somehow, that would be great! I'd love to see what you guys did

15" in the right enclosure will blow a 18" in a cramped enclosure all day (I guess your going for looks over performance). I would hate to have an 18" sound like shit just to have one when I could get a 15" and do some damage but I guess to each its on. Grand Prix's do not have huge trunks like that.

15" in the right enclosure will blow a 18" in a cramped enclosure all day (I guess your going for looks over performance). I would hate to have an 18" sound like shit just to have one when I could get a 15" and do some damage but I guess to each its on. Grand Prix's do not have huge trunks like that.

Why can't I just cut a big hole in my roof and let it hang in there? Maybe just replace my steering wheel with the sub and free air it.. Talking about "In your face" bass!

Didn't We Already Discuss This Before On His Other Thread. Or Threads....

You're Getting The Same Damn Answers I And Everyone Else Said On Those Particular Topics.

And Jay-cee Basically Reiterated What I Said There.

Just Because You Want An 18" Doesn't Mean You Can Run One, I Have A No Compromise Approach When It Comes To Car Audio, If All I Had Was That Grand Am And I Did Want 18"s, I'd Take The Back Seat Out And Wall It.

But, That's Kind Of Impractical And...Well, Stupid...For A Daily Vehicle Atleast.

Trust Me, The 15" Will Do Better In Your Vehicle's Environment, You Do Not Have The Airspace.

I'd Really Be Worrying About Your Electrical And Amplification Other Than This Shit.

And Just To Clear It Up, Performance > Looks.

If You Want To Get An 18" Just So You Can Show It Off, Then That's Fine.

But Don't Come Crying To Us When You Get Blown Out Of The Water On The Meter Or Audibly With Two 10" Drivers Or Even 1.

(Which Personally, Is More Impressive To Me.)

Having an 18" in an enclosure that won't allow it to play low notes is the most amusingly stupid thing you could possibly do IMO. You'll get laughed at by everybody.

15" in the right enclosure will blow a 18" in a cramped enclosure all day (I guess your going for looks over performance). I would hate to have an 18" sound like shit just to have one when I could get a 15" and do some damage but I guess to each its on. Grand Prix's do not have huge trunks like that.

Why can't I just cut a big hole in my roof and let it hang in there? Maybe just replace my steering wheel with the sub and free air it.. Talking about "In your face" bass!

Please be for real and stay on subject, but by all means do what you want to do its your money, your car and your system. Just let me know when you throw that 18" in there so I can here and

I actually saw an install where they had a w7 in the steering wheel. Some magazine a few years back.

Going with either 2 12's or a 15. Thanks for being dicks about it guys! really helpful

Going with either 2 12's or a 15. Thanks for being dicks about it guys! really helpful

No one was being dicks..they were just telling the facts

Going with either 2 12's or a 15. Thanks for being dicks about it guys! really helpful

You didn't have the money on page one. Did the 2nd page of posts somehow generate money?

you know, if you ever need to know what can fit.. all i need is the dimensions of the cargo area.

If you need a design created for you, that's through PMs.

I just went through 2 whole pages of speculation of what can\will fit.

Just give me the dimensions of the cargo area you are willing to take up for a box so i can narrow your sub choices down now.