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SwiftCelGTS
11-05-2006, 11:12 PM
is this a good idea? i've heard it can make all the difference in the world in how a sub sounds in a box.. it basically makes the sub think the box is bigger correct? i want to put a 12" L7 in a sealed box but its only .88 of airspace. i'm afraid it won't sound very good in a sealed box.

azbass
11-05-2006, 11:14 PM
i use it in all my sealed boxes. and works great.

SwiftCelGTS
11-05-2006, 11:16 PM
but how much?? was it a noticable difference in the sound?

Volenti
11-06-2006, 03:55 AM
The change you hear after adding fill has little to do with the driver appearing to be in a larger box (this does occur but the audible affects of this are very subtle) and everything to do with the damping properties of fill.

It's similar to how shock absorbers function on a car, if your shocks are worn out the car keeps bouncing for a little bit after it hits a bump, this is what can happen in a sealed box with no fill, adding fill is like fitting a new set of shocks, it makes the sub stop faster after a bass hit instead of ringing.

The end result of this is it lets the sub more accurately track the audio signal, fast and complex bass passages will sound fast and complex, rather than a smeared boomy mess.

Note that some subs and enclosure types have better inherent damping than others and in some cases the effect of fill isn't very noticable.

SwiftCelGTS
11-06-2006, 10:12 AM
The change you hear after adding fill has little to do with the driver appearing to be in a larger box (this does occur but the audible affects of this are very subtle) and everything to do with the damping properties of fill.

It's similar to how shock absorbers function on a car, if your shocks are worn out the car keeps bouncing for a little bit after it hits a bump, this is what can happen in a sealed box with no fill, adding fill is like fitting a new set of shocks, it makes the sub stop faster after a bass hit instead of ringing.

The end result of this is it lets the sub more accurately track the audio signal, fast and complex bass passages will sound fast and complex, rather than a smeared boomy mess.

Note that some subs and enclosure types have better inherent damping than others and in some cases the effect of fill isn't very noticable.

thank you. so polyfill isn't capable of having a negative effect then correct?

JimJ
11-06-2006, 10:15 AM
The change you hear after adding fill has little to do with the driver appearing to be in a larger box (this does occur but the audible affects of this are very subtle) and everything to do with the damping properties of fill.

You sure about that? :)

dalucifer
11-06-2006, 10:25 AM
I actually used fiberglass insulation. Works better than poly fill IMO. :)

05AztecRed
11-06-2006, 12:51 PM
Used polyfil in all three of my sealed subs. Sounds good. I put in 1lb. poly per 1 cu. ft.

xxxpower
11-06-2006, 02:27 PM
can you get this at homedepot or lowes and do you just stuff the box with it

luvinthebass
11-06-2006, 02:29 PM
can you get this at homedepot or lowes and do you just stuff the box with it

rip a pillow up and use that cuz it's POLYFILL well that's what i did:rolleyes:

luvinthebass
11-06-2006, 02:30 PM
ghettoness to the xtreme righ there^^^

xxxpower
11-06-2006, 02:31 PM
and you just stuff the box untill its full of polyfill

luvinthebass
11-06-2006, 02:33 PM
I just put some in the very back of my box and quit adding some till i filled the box half ful and it was deeper bass and no boomyness resonances from a boomy song, so i guess it improved SQ a bit too :)

reneeb7363
11-06-2006, 02:34 PM
read this page: http://www.moodym.com/audio/fiber.html

(originally referenced in forum: http://www.caraudio.com/forum/showthread.php?t=177860&highlight=poly+fill )

luvinthebass
11-06-2006, 02:36 PM
i've never tried polyfill in a ported box though :ponder:

JimJ
11-06-2006, 02:39 PM
No real reason to...it's used in transmission lines to simulate a full quarter-wave length.

Volenti
11-06-2006, 07:04 PM
thank you. so polyfill isn't capable of having a negative effect then correct?

Unfortunatly there is no free lunch, adding fill can reduce the peak of a boxes response by up to 3db (this is generally desireable for SQ), so don't use it if you are after maximum spl.

SwiftCelGTS
11-07-2006, 04:14 PM
ok i bougth my sub, it's a 12" Kicker Comp VX and it is going in a 1.25 cuf sealed box. the amp i'll be using to power it is a KX600.1 that makes 710W. should i use polyfill with this setup?

Volenti
11-07-2006, 07:01 PM
I would try it and see how you like the sound, there aren't any hard and fast rules with fill, and it doesn't need to completely fill the enclosure to have an effect, you can just half fill it to get a little damping without loosing too much peak spl.

SwiftCelGTS
11-08-2006, 12:07 AM
yah i will play around with different amounts until i get it to sound good

ruger
11-08-2006, 12:34 AM
poly does work with ported designs.