Car Audio Mythbusters...
Intermediate
Joined: Jun 2006
Posts: 49
Likes: 0
I never knew the myth to be poly would increase SPL. The Poly is supposed to make the response more linear but you will loose efficiency in the process. Basically, you sacrifice total output for the sake of SQ. If you want as much output as possible the las tthing you want is poly in the box. Poly cannot fix an improper enclosure.
Pro
Joined: May 2007
Posts: 744
Likes: 0
From: WayTooCloseToNY Northeast PA
The SPL we're talking about here is frequency dependant. Look closely at the graphs on the first page and you'll see that it certainly does increase efficiency at in some areas at the expense of others. Overall output efficiency is therefore a function of the frequencies reproduced. The test methods behind those charts are identical in every way except amount of polyfill in the box, and the relative responses are normalized with respect to input power, since that changes with impedance. Note these are NOT RTA graphs. Further, polyfill and/or other materials are used in enclosures to tailor the sound. This has nothing to do with whether the boxes are proper or not. Proper is in the ear of the beholder.
