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View Full Version : A Wall Question, Please Help



BoomCrew
03-09-2005, 01:36 AM
i have a 91 cavalier and i was thinking of building a wall and replace my back seat with a wall. i would have 4 12's in it. If i were to build this wall in my car what kind of gains would i be looking at versus have subs in my trunk in a crx style box?

not only for spl but also daily driving gains are what i am looking for...

thanks

jellyfish420
03-09-2005, 01:50 AM
cabin gain is a very wonderful thing;)

joeldirt
03-09-2005, 02:29 AM
As above, Cabin gain would be signifigantly improved. Basically putting all of your sound waves into the cabin of your car minus a bit. If you even knew how much bass you were losing when letting it all bounce arround and escape out your trunk you would have concidred this a while ago. This aplication isnt for everyone, but it isnt that hard to do actually. PM if you want any ideas. There are a few ways you can put a baffle between your trunk and cabin.

BoomCrew
03-09-2005, 02:18 PM
i think i am going to build the wall in a month or so after i buy the fourth 12. i will be using mdf to build a baffle to block off the trunk. then i will be using a "false" floor to make a level surface over top the butt rest on the back seat and then setting 2 boxes on top of it. the two boxes will be for my wall.

how does this sound? if there is a better way please let me know.

req
03-09-2005, 03:11 PM
i have a 94 cavalier. basically the same body\trunk\inside.

the back seat comes off with 2 bolts (underneath the front. i believe its like 11mm or 1\2in head- not sure)

take all that crap off, get rid of the seatbelts, take the plastic moulding thats around where the seat-backs are... remove the backs of the seats, and take up the carpet in the trunk. i would advise a good amount of sound deadening if you have it.

then get fiberglass, and make a mould of the metal where the back seat sat (all the way up onto the rear deck and seal that entire area ... construct a baffle of MDF that slants from the rear deck to the front part of where the seat was... and make some fiberglass (fleece) stretch to go round the edge of the baffle to your mould you made. seal it all round the edges with expandible foam, and 'glue' it down to the metal with the foam (stops some vibrations too)

its all theory, but i think id work with a little fancy fiberglass work... then put a nice huge slot port down the center. but your trunk will be like 15 cubes 0_o

prolly more. so i dunno how youd measure that. LOL :)

BoomCrew
03-09-2005, 03:51 PM
im just playin wit the idea of a wall, but would i see a nice gain by using a wall and if so i will go by what req says. I want to be as loud as i can... or do u think just a crx style box wit 4 12's would be good enough?

joeldirt
03-09-2005, 11:21 PM
The smaller the vehicle, the greater the gain. bottom line. putting in that wall will allow you to make your car apear to the subs that the car is even smaller in thus giving you larger rumbling bass up front. ( I am assuming you are building a wall with the subs and enclosure in the trunk facing through the wall sealed to the wall so that the sound waves go through the cones of the subs into your cabin. Having holes cut to accomodate the subs and ports) Is this right?

One of the quickest way to ruin the illusion of up front bass is to have the rear of your vehicle rattling. It doesn't take your brain long to figure out that the subwoofer is in the same place as the rattling body panels. Take care of these noisy panels by using a combination of sound deadening sheets (Dynamat or similar), expanding foams and other sound deadening materials. Then using a test tone CD sweep through the bass range and see if certain frequencies cause other panels to vibrate. Sound deaden these areas and repeat until your rattles are taken care of. Then sit back and enjoy your new car audio system. Just make sure you leave enough juice to start the car. (compliments of car audio help) there was an article about this a few months back suggesting a wall is the ultimate idea if you are willing to take the time to do it right) you WILL gain signifigant difference, and the sound dampening is important too

BoomCrew
03-10-2005, 01:17 AM
i was thinking of maybe building a box like iggster did. and Joeldirt u got anypic of what ur talking about the box in the trunk. Im not following the box and wall and sound waves threw cone


Like www.sounddomain.com/id/iggster.

joeldirt
03-10-2005, 01:57 AM
i was thinking of maybe building a box like iggster did. and Joeldirt u got anypic of what ur talking about the box in the trunk. Im not following the box and wall and sound waves threw cone


Like www.sounddomain.com/id/iggster.

if I could from this work computer I would. they got their asses puckered so tight in the USMC computer network settings wont let me do jack SH**! I think the article was in Novembners issue of Car audio and electronics.

Basically what I was trying to say is once you make a wall in your car behind the back seat, and have it sealed, you will also have to make a wall in the back dash to completely seal off the cabin of the car and the trunk of the car. Now, match the enclosure angle to the back seat baffle/ wall so that they match perfect. YOu can then remove the center of the wall so that when the enclosure is butted up to it flush, the subs and ports are visible. YOu cna then use caulking and wood screws to secure the enclosure to the wall( you want to be able to remove the enclosure if you have to thats why the caulking not glue). You have just achieved an increase in cabin gain. Carpet or finish the product behind the seat as you wish to make a clean custom look.

I hope I made any sence. Please any one if you understand or know a link to the article I am refering to explain. I tend to have a hard time putting into words what I see in my head.

Maybe I have you all wrong. Are you trying to put the entire enclosure in the back seat and not in the trunk? Because I am talking about having the enclosure in the trunk yet isolating the bass output mainly into the cabin......

BoomCrew
03-10-2005, 08:08 AM
i was thinking about putting the subs in the back seat so i could run 2 boxes with 2 woofers in them like the link above is. i dont have the room in my trunk to put all 4 that is why i was thinking the back seat and then i would use a piece of mdf and block off the trunk.

req
03-10-2005, 09:57 AM
somthing like this was my idea

http://img239.exs.cx/img239/7628/cavalier0jd.jpg

i think i could pull off a sweet wall...

Nikuk
03-10-2005, 11:19 AM
somthing like this was my idea

http://img239.exs.cx/img239/7628/cavalier0jd.jpg

i think i could pull off a sweet wall...


what is the point of that design? looks or sound?

req
03-10-2005, 11:24 AM
i dunno- i just threw it together, i dont know if 4 12's can fit across the front (staying below window level) with a port while using the trunk as the actual box space.

DBfan187
03-10-2005, 12:35 PM
somthing like this was my idea

http://img239.exs.cx/img239/7628/cavalier0jd.jpg

i think i could pull off a sweet wall...

won't work, cancellation out the ***.

Find Loyd's sig, click his link. Build wall.

req
03-10-2005, 01:22 PM
won't work, cancellation out the ***.

Find Loyd's sig, click his link. Build wall.

because they face each other and the port is in the middle?

yea, i thought about that. but i just drew a picutre. the principal of making a wall the way (with fiberglass under and a baffle at the front of the seats) is what i was trying to show, not how to set up the speakers\port

if that makes any sense :p:

fiberglassing on the metal seat area into the trunk all the way up and around the top rear-deck, then making a box in the trunk, and a box in the car, and connecting them with fiberglass was my idea. thats all :p:

how the port\speakers are set up in the cabin is irrelavant to me because i cant measure that. if you understand me :)