View Full Version : box stuffing?

10-07-2007, 09:20 PM
Is it logical to use polly fill stuffing in my sealed boxes? Why?

10-08-2007, 02:46 PM
It will flatten your response, lower your Qtc (in most cases but it is possible to raise it if you over-stuff; this is why people say it makes the enclosure seem larger but that is not really a true statement), and it will help dampen the upper order harmonics.

It will NOT make it louder and it will usually lower your max SPL. But, due to the lower Qtc, it will help give you a little more low end.

Whether or not it's logical is based completely on what you want from your setup.

10-08-2007, 06:54 PM
and since it's pretty cheap and easy to swap in/out, testing is your friend to see which way you prefer...

10-08-2007, 06:56 PM
box stuffing, a kinky side of car audio.

10-08-2007, 06:57 PM
Stove Top?

10-08-2007, 08:03 PM
I found this on a site the other day:

How much polyfill do I need in the enclosure?
Polyfill is used for absorbing standing waves in an enclosure. In non-servo subs, it is also used to occasionally adjust the Q value of bass roll-off. In this case, a heavy amount of polyfill will be needed to achieve the desirable Q value. The downside of this practice is that low level resolution is somewhat compromised. This is mainly caused by the nonlinear absorption rate of polyfill. Anyone who has built their own full-range speakers knows that too much polyfill is not always a good thing. Overstuffing the enclosure can make the sound less dynamic.

10-09-2007, 01:21 AM
I built new boxes and stuffed them,after advise I removed it and they sound much better. 2 pioneer TS-W307D2 in 1.22cu wedge shaped 3/4 mdf each.jlaudio 250/1 amp(works awesome)

10-10-2007, 03:56 AM
I read one site which said at least 50% but I don't think I'd go that far.

The fill is used to stop standing waves which are waves produced from the transmitted wave and the reflected wave. In a sealed enclosure (maybe ported, too) the sub functions by using pressure and I think too much fill can get in the way of that.

Excellent Standing Wave explanation here: http://en.wikipedia.org/wiki/Standing_wave