23 replies to this topic

[Banana_Boat]

Hey all. ive searched for hours and found nothing that's helps me out.. I didn't know whether or not to post it here or Groundpouder/SPL section

What i want to know is how to design a wall ? Iv'e never built anything to this scale before ever!!!

I will be using 2 DD 9515's in a hatch back ae82 corolla.

I just want to know how do you make a good seal between the floor and the body of the car without drilling any extra holes ?

with the port is it best to put it on the side of the wall ? or the top or bottom or the wall ?

securing the port to the box ? i know you can't get a drill underneath the wall or ontop of the wall, Is the only want to put heaps of fibreglass or use a comb of L bracket and fibreglass ?

Any other tips would be great

[Lunchbox.inc]

WELL... big subject this, i really must recommend going thru as many build logs as you can to see how others have done it, if you check out my charade build HERE you can see the inside of my enclosure and how we secured the baffles/ports, mine is a bandpass, so not necessarily what you'll be doing, but it will give you a fair idea at least...

basically to build a proper wall, your enclosure needs to be coupled with the body extremely well, and all gaps around the box sealed up airtight... whenever somebody asks about walling their car, i usually give them the reply that to properly wall your car, you must be willing to write off the car... now this isn't always the case, if you look at the phoenix gold astra, everything in that car is 100% removable, but as Scott will tell you, it was VERY arduous task building it removable...

in reality, it is almost impossible to wall a car, and not have to drill new holes into the body, you can do it, but at the sacrifice of strength, which IMO, is one of the most important aspecs of a wall...

making a good seal between the enclosure and floor is usually done by building the enclosure on the floor, and screwing/bolting it into the sheet metal, sides of the enclosure are often screwed/bolted into the inside of the C/B-pillars and the roof of the enclosure is usually wedged in position then screwed into place, this can be done via the back doors in a 4 door, or removing the rear side windows in a 2 door

once you have the shell in place it's a case of making it STRONG, which involves adding extra layers of MDF to the insides usually 3-4 layers of 18mm for the shell and back, then the baffle can often be twice that for a big numbers car...

your port arrangement will basically depends on what you want to achieve from the car, if you want loud musical then a bandpass, or central port works well, if you're primarily burping the car, and wanting numbers, then having the port on the drivers side is the way to go... quite often the port on a nubers car will simply be the width of the baffle itself, which is where an 100mm+ baffle really comes in handy...


all in all, a wall is definitely not for the faint hearted, but ALOT of fun to build, and even more fun to enjoy whilst cruising around...

[Banana_Boat]

Yeah well if i build a wall the thing won't be coming out again lol...

well if i must il bolt down the MDF to the floor pan. As for when you say screwing to the c/b pillar, Do you just use screws and drill them from the inside of the wall into the metal skeleton ? ( without going all the way through the car lol)

As for making it strong, For the first layer of MDF would i use 20mm ? or the 18mm as you mentioned ? ... Also for fiber glassing. Is it necessary to fiberglass the whole of the inside of the box ? or only just reinforce the joint's with a couple of layer's ?

Well i just want it as a daily, Don't wanna compete or anything.. Just something to have fun with and to shake some stuff up But i more just want a groundpounder.. Somthing that's reliable for a daily system, yet has the punch if i need it..

I have been meaning to see if anyone in QLD has a wall setup, so i could learn off how they did there's and use that on mine.

[D34M0N.inc]

And if you can't fully seal it at the roof etc expanda foam can be used to help

[Banana_Boat]

D34M0N.inc, on 18 January 2012 - 08:17 PM, said:

And if you can't fully seal it at the roof etc expanda foam can be used to help

Yeah i have seen a few people use a heap of the stuff at the top and side of there wall's,, thank's for the head's up on that D34MON , i totally missed lol

[RAD]

With regards to drilling into the car, you make your first layer that makes the "skeleton" of the wall. It only needs to be one layer of 18mm, what you're trying to do with this layer is to use chipboard screws to drill this layer into any B or C pillars, glue it to the outer skin if possible, or any roof braces.
Basically, get this layer attatched to as much of the car as possible, and with the remaining layers, you're adding wood so the skeleton layer does'nt flex or move.

Fibreglassing the entire wall is'nt necessary, you can simply fibreglass the corners of the wall to help with the strength, and to seal it air tight.

A quality fitted wall with two layers + fibreglass should be sufficient, especially for a daily.

[D34M0N.inc]

Some people fiberglass all the edges, and just use resin for the walls. But yeh lunch and rad have the right idea's and is good info for when i wall mine.

[ryzaa]

Build it Big
Build it Strong
Ensure its well Sealed
And then design it with the thought that the whole car is the enclosure., or ask help from knowledgeable people from around here.

The shell of it all would be your main focus to start with as far as strength and the like goes, and then perhaps leave the rest unfibreglassed, etc, just so its able to be moved around a bit so you can play/experiment, if you so desire, makes it much easier to pull it apart and chop/extend/change things, until you get it right.

[Sorin-Andrei]

This might be a dumb proposition but it occurrs to me that unless you're bandpassing it, there is too much airspace for 2 x 15's in a wall in that car... i mean if it was a daihatsu mira or something, totally different story, but yours is a fairly average sized hatch... i think you're better off no-walling it if you want to use it daily....

Or bandpassing it.

mmmm...bandpass...

[Banana_Boat]

How would i go about making a bandpass ? i heard of them but never seen them before... I don't think i can fit a big enough box for daily and fit all the amps in... I may be wrong though. but then again, iv'e never designed a box before ever lol I only built a whole heap of boxes that i got the Plans from DD Phil when he was helpfull..

Edited by Banana_Boat, 19 January 2012 - 07:49 PM.

[Carr]

Hope you don't mind me posting a question in your thread, I am also building my first wall.

What is the best way to still allow access to the fuel pump? I have seen some with an access hole made in each layer getting bigger and screwing in. Others just don't seem to worry about it. I was thinking about replacing the pump and seal and then just build over it.

[RAD]

Do the access hole getting bigger and bigger. Don't just leave it, if you let the tank run empty or the pump is a dud, you've got $$$'s i materials and time invested for a 30min step.

[BIGW]

Banana_Boat, on 18 January 2012 - 08:39 PM, said:

Yeah i have seen a few people use a heap of the stuff at the top and side of there wall's,, thank's for the head's up on that D34MON , i totally missed lol

Why do people use this? from an acoustic sealing point of view, it is quite possibly the worst thing you can use as it has no mass to it. Why not use F/glass, MDF or mastic sealants?

[Lunchbox.inc]

BIGW, on 14 March 2012 - 01:39 PM, said:

Why do people use this? from an acoustic sealing point of view, it is quite possibly the worst thing you can use as it has no mass to it. Why not use F/glass, MDF or mastic sealants?

alot of the time expandy foam is used as a base, and then glassed over...

in my own experience i found the use of expandy foam by itself is still great, as with enough of the stuff, it works just fine to isolate... is enclosed spaces a small amount goes a LONG way, and also places quite a bit of pressure on the exterior panels of the car, it may not have alot of mass to it, but it still works quite well for it's intended purpose, as it's cheap and goes a long way...

[D34M0N.inc]

Yeh the stuffs great for sealing bigger area's as it expands 3 times it's size so a nice amount of pressure is on the surrounding panels.

I use it in the skeleton of my boot lids to reduce rattles.