bass-box and mdf question

[LightWarrior]

i'm going to B&Q this afternoon to buy the mdf to build my boot install. I'm putting the sub in on the right, angled upward a little, and the amp on the left. I'll paint a picture later. for now though, i need to know what thinkness of mdf i'll need to use to hold a 12" sub without any hassle.

Also, can i just build it without a back??? it seems pointless given that it'll be jammed up against the contoured inside of the boot. I was thinking i could just add a 2nd layer of sound deadening behind it?


I want to die peacefully in my sleep, just like my gran did, and not screaming like her passengers were!

 

[Jordy]

MDF

I used 1/4 inch thick mdf on my bootbuild. For extra strength and air tightness i reinforced the inside of the boxes with fibreglass matt.

 

[Tom]

It should be 3/4" MDF all round.

 

[LightWarrior]

Cheers Tom, i'll have to get it tomorrow now, thats the missus arrived. so will i need to build a back on to it?


I want to die peacefully in my sleep, just like my gran did, and not screaming like her passengers were!

 

[LightWarrior]

By the way, does anyone have boot measurements. In know that thats Totally lazy, but why make it hard for myself?


I want to die peacefully in my sleep, just like my gran did, and not screaming like her passengers were!

 

[Paul R]

@Light... the box must be air tight! so you need to put a back on it! unless you fibreglass the box into the boot but thats alot of work and the box would be fitted perminatly!

Up to you!

Paul R

 

[LightWarrior]

i'll buy some fibreglass matting then, and lots of masking tape, and take a mould of the inside of the boot on the sub side. i wont bother on the side thats geting the amp though. that'd do wouldn't it? then i can use velcro on the back of the bass box, to stop it mving, and screw it into an mdf boot-floor, which i'll be making too.


I want to die peacefully in my sleep, just like my gran did, and not screaming like her passengers were!

 

[Paul R]

That would be ideal... if you made a fibreglass mould of the back side then fibreglass that to the mdf box..wouldnt bother with the velcro, just screw it down... make sure you vanish the box inside to make it airtight, need a couple of coats aswell!

Also, a good tip is to use sticaflex (not sure on the spelling) alone the joins alone the box....

Paul R

 

[Tom]

No need to varnish the MDF, its air tight enough

Velcro will not hold a box in place, remember if you have a smash it could come flying forwards and take your head off.

 

[Paul R]

You sure about the MDF tom? i swear i have always be told that mdf isnt airtight?

PAul R

 

[Tom]

Its airtight enough for a speaker box. More air leaks out through the speaker itself than through the MDF.

 

[LightWarrior]

i will be screwing it to the floor, but just thought the velcro would help stop any movement at the back and top. How many layers or fibreglass mat will i need to make the back strong enough.

@ Paul, i'll use sikaflex on all the joints instead of P38


I want to die peacefully in my sleep, just like my gran did, and not screaming like her passengers were!

 

[LightWarrior]

oops, did a double post

 

[Tom]

LOTS! Make the back 10+mm thick.

 

[LightWarrior]

damn thats alot.... but ok...


I want to die peacefully in my sleep, just like my gran did, and not screaming like her passengers were!

 

[Tom]

Yup. What sub are you using?

 

[LightWarrior]

The JBL GT4-12" powered by the jbl GTO755.6 as recommended in the other thread i had a few days ago.


I want to die peacefully in my sleep, just like my gran did, and not screaming like her passengers were!

 

[BlackBravo]

on teh fiberglass
at least 8 layers of average mat (2oz) but go for ten and you`ll b cool

Pete

 

[LightWarrior]

thats gonna cost innit...
haven't used fibreglass sheets before, just pots of P38 and P40 to fill in the holes in the arches of my nissan micra i had a couple of years back... my first car it was. in the family 8 years and ZERO breakdowns. i loved that car...


I want to die peacefully in my sleep, just like my gran did, and not screaming like her passengers were!

 

[BlackBravo]

try these there quite reasnoble

http://www.cfsnet.co.uk/

Pete