View Full Version : Polyfill and vented enclosures
05-23-2012, 02:48 AM
Does anyone use poly in their enclosures? Anyone have experience with how it effects volume/ tuning/ efficiency? If you use fill instead of batting what methods do you use to keep it inside?
I'd like to use it in a temporary prefab thats 3.3 ft^3 (b4 port/sub displacment) w/ a 41hz tune. I'd like to shoot for 4-4.5 ft^3, how much fill will achieve this? I was told 1lb = .5 ft^3... In that case 2lbs should net 4.3. How will this effect tuning? My vent measures 3w X 11.5t x 12.25d (straight center slot)... In theory the same size port @ 4.3 equals 35hz... Would this hold true in the real world?
05-23-2012, 03:00 AM
Ultimate Polyfill Subwoofer Enclosure Resource - AudioJunkies (http://audiojunkies.com/forum/blog/4777-ultimate-polyfill-subwoofer-enclosure-resource.html)
If you can find another source for this article it used to have charts of somebody's tests and measurements.
05-27-2012, 07:34 PM
I use it a lot when the enclosure/port ratio is large and almost always in sealed enclosures.
05-27-2012, 07:39 PM
use fiberglass insulation instead. It works much much better just ***** to work with.
05-27-2012, 10:25 PM
It has been tested by a few that 1-1.5 pounds of poly per cubic ft of volume is a good rule to follow without lowering the Q of the design too much and lessening the effect of the poly. SO, in 3.3 cubes, you will likely have a lowered sensitivity of the enclosure so you have may have to use less due to the size of the box, and the fact that it is ported, but you should notice some effect with the range given. So closer to 1 lbs of poly will likely show changes in the response more accurately. Hope that helps. :D
There has been testing on this as well by a few people that I used to have the write-ups on. I do remember from that though that the 1-1.5 lbs is a very accurate rule to go by and I have tested this as well with great results. Ill have to get the pics and information again as they were on my old windows computer and did not transfer from my hard drive correctly to my mac. I lost a lot of information from that computer if some may recall that. :(. But this rule holds.