I've had my 2 12" magnums for quite some time now and still haven't set them up. I'm pretty close to it though, now that my alternator is here. Anyways, I have questions regarding enclosure size. I can fit a 2 cf box in my trunk with enough room to spare, but after sub displacement, this gives only 1.6 cf (0.8 per sub) right? Is this good enough? Will there be big difference between 1 cf after displacement per sub and 0.8 cf? Most people seem happy with 1 cf, but I don't know if that is before or after displacement. Each one will be getting like 600 watts from a PG tantrum 1200.1 amp. If I need more volume, I might just port one and sell the other one, or use it for a home stereo system.

Should be good to go. I know SI reccommends a little mix of Poly and FG so once you've done that, you should be golden. Let us know how you like it!

i read an intence review onpoly fil ad this kind of things. the person who did it had all this fancy equip to measure the diferences with amounts of polyfil. his end result was at maximum you can get about a 30-40% increase in box size volume with a perfect polyfill job.

so i estimate if you stick to about 1 pound per CF you should get around a 20-30% increase.

youll be fine.

a pound of polyfill per cu ft?

yes i belive so,

if you dont like it just take some out, or add some more.

until you find the spot you like.

and i believe nick suggest fiberglass insulation on the walls of the box right guys?

and i believe nick suggest fiberglass insulation on the walls of the box right guys?

Yes yes and yes. The combination of fiberglas lined walls (the home insulation type, not fiberglas mat/cloth) and polyfil stuffed enclosures is hard to beat when you are trying to increase effective enclosure size. The difference between 0.8 and 1 cube though? Minimal. AKA: non-audible. I would still line the walls with fiberglas and stuff the rest with poly.

But then again...what do I know?

The combination of fiberglas lined walls (the home insulation type, not fiberglas mat/cloth)

So you mean I shouldn't buy fiberglass resin and cover the inside of my box with it? I don't want to deal with the house insulation fiberglass stuff. It turns out that my trunk will allow 0.95 cf per sub after displacement, so I should be at least ok with just polyfill right?

Edited May 3, 200421 yr by magic_wizard

Covering the walls with fibergals resin will only aid in sealing the box if it's not already sealed. FB resin does nothing to effectively increase box volume. If you don't line the walls with insulation, at least put polyfil (pillow stuffing) inside.

Thanks Nick. I'll do that, and I'll think about lining it with fiberglass too. Where do I get this fiberglass, and do I line it with screws or glue? Hopefully glue, because I don't want to drill too many screws into the nice box I'll be getting. Also, I know this stuff is hazardous, but what particular precautions do I need to take when working with it? Would gloves, goggles, and a filter do the trick?

yes, I too need to know about this fiberglassing of the walls. I am picking my car up later today from having my EQ installed and tuned (I never have been good at tuning it) then I am going to be adding poly fill and possibly this fiberglass you speak of.

I dynamated the doors and trunk lid yesterday and wow did it do wonders.

It's standard fiberglass insulation he is speaking of. You know the type used to line the walls of houses; it's usually pink or yellow in color.