how thick are your sub boxes?

[fitvpower]

hey i would really appreciate some help on this topic: i just wanna know what is the idea mdf thickness i should use when building a sub box. The shape will look something like this: http://www.gspr.com/blau/images/sub_box_single_300.jpg and will be 45 cm long. The recomended internal volume will be 31.148 L but i'm building 46.3725 L and leaving 15.2 L for internals. I'm intending to mount an IDQ10 inside this one and running it as a sealed box design. thnx in advance for any helpful tips

[Limbo]

i used 15mm, the more solid the box is the clearer the sound ends up and reduces distortion. That's what i found out from building my own box.

I also used proper timber rather than MDF, cost more but the finish produce produced great sound.

And then it got stolen from Lidcome station ;(

[tron07]

The 2/3" MDF should be good enough, brace it if you need a stronger box, not use thicker MDF. Make sure you seal the gaps with sillicone or some glue to make the box air tight/properly sealed

[Limbo]

Yeah i used liquid nails to seal it

[fitvpower]

i used 15mm, the more solid the box is the clearer the sound ends up and reduces distortion. That's what i found out from building my own box.

I also used proper timber rather than MDF, cost more but the finish produce produced great sound.

And then it got stolen from Lidcome station ;(

bad luck dude, timber would be better - but did you mean chip board or proper timber sheets cut to pieces? ps: it must really heavy if it to be made from solid timber.

[fitvpower]

The 2/3" MDF should be good enough, brace it if you need a stronger box, not use thicker MDF. Make sure you seal the gaps with sillicone or some glue to make the box air tight/properly sealed

yea tru tru, if i go mdf then solid timber braces for sure

[arverson]

what do you mean by 'leaving 15L for internals'??. the idq isnt THAT big..

[fitvpower]

well, the sub itself, seals, braces, damping materials, well i've given some lee way but + or minus a few litres anyways,

[Limbo]

yeah i had timber sheets (solid pieces) which i got from a friend for free.
Chipboard is actually worse than MDF.

Yeah my sub was super heavy

[mr ©harisma]

My sub box has 25mm MDF sides, dual 18mm MDF rear and 25mm perpex on the front. Nice and solid... :D

Would probably go with a minimum 18mm MDF for most situations.

[fitvpower]

My sub box has 25mm MDF sides, dual 18mm MDF rear and 25mm perpex on the front. Nice and solid... :D

Would probably go with a minimum 18mm MDF for most situations.

i had a look at bunnings today, they only had 16 mm max for mdf sheets. I might opt with pine sheets. Is this a good option?

[Fhrx]

Generally if you're making them from MDF then 18mm is the minimum I'd recommend for subwoofers 10" and larger.

When we make enclosures here we generally employ 18mm or 25mm. However we've been known to utilise 36mm or even 42mm depending on the application. We use liquid nails to sealed them internally, paint them in polyester resin externally to weather proof them, sound deaden the inner walls and insert dacron into them to help improve the damping and resonance characteristics. :D

[euro_tr4sh]

hey marty, im an active member on mea, and im well aware of your shop, abilities and contributions to the car audio scene (mag contributions etc...) so please dont take this the wrong way :P i worked at audioart under yanddy when he still owned it, and basically he taught us that dacron was the antichrist when it came to building sub boxes, kind of a band aid solution to small boxes, do you use it in most of your applications or just where you cant meet the space requirements for the sub? doesnt it "fool" the sub into thinking its in a bigger enclosure? i may sound a bit nieve but i can only take from what iv been taught, so yeh, just thought id get some info on it from one of the masters of car audio :)

ps- if time constraints allow, or im building a box for my own personal use i like to give the joins on the inside a single coat of fibreglass, seals it nicely and strengthens it up aswell

[ICACHA]

i use it sometimes and dont use it other times, there is no proof dacron works or doesnt work, do what you feel is right...

[Fhrx]

Perhaps I should have stated that we utilise it when required but don't always use it as an absolute necessity. However; this requirement does see us employing it in 99% of the sealed enclosures we build.

You're right about volume though; it is all to do with the size of the enclosure and what we're trying to achieve from it. Generally speaking; larger sealed enclosures tend to offer a superior, flatter frequency response curve and lower bottom end roll off (to a degree of course). When we calculate the enclosure size we require in car installs, nine times in ten it results in quite a large enclosure (say 1-2 cf or more). Therefore we quite offen use dacron so we can reduce the size of the enclosure and not take up half of the boot. The amount we use also varies depending on each application and you have to be careful not to overdo it lest the fill starts having a negative impact on the rear loading of the subwoofer cone.

If my memory serves me correctly; there was an article once written by Tom Nousaine which also touched on the heat dissapation side of using dacron. My memory is a little rusty here but if so then i'm with George in that I'm not convinced it really makes that much of a thermal difference.

[fitvpower]

whats dacron

[amurray]

depending on what u want the box for, SPL, SQ, everyday... u can use varrying sizes... for example. for SPL we used 16mm satan mdf. with 25mm sides and back front, with 32 mm port sides ( slot port )...

Dacron is the shiz they put in stuffed toys.. bascily... it in a way tricks the sub in thinking its got a larger volume box.

[euro_tr4sh]

could it possibly cause trouble with a woofer that has a vented pole? if some stray fibres got up there could it cause damage to the coil? i've never seen it happen let alon heard of it so im guessing its not something to worry about, on the dacron trail of things to i guess what are your opinions on putting dynaxorb in sub boxes?

[amurray]

as in sound deadining on the inside of a sub box... are u insane?

[euro_tr4sh]

as in sound deadining on the inside of a sub box... are u insane?

no, and your obviously not that bright... "dynaXORB" they're diffuser plates, and because you think putting dynamat on the inside of a sub box is "insane" im not gonna bother explaining diffuser pads to you... google it

[fitvpower]

depending on what u want the box for, SPL, SQ, everyday... u can use varrying sizes... for example. for SPL we used 16mm satan mdf. with 25mm sides and back front, with 32 mm port sides ( slot port )...

Dacron is the shiz they put in stuffed toys.. bascily... it in a way tricks the sub in thinking its got a larger volume box.

hmm so filling a closed box with 'stuff' dacron, will trick the sub into thinking its gota larger volume to handle. But wouldn't the dacron take up some space and reduce the overall volume of the box. i'm a bit lost here :confused:

[tron07]

Is the dacron stuffs same as polyfill? or its more like accoustic sponges?

[ICACHA]

same same, also known as pillow stuffing to others...