Polyfill
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the u can still use the polyfill..
David taught me that usin polyfill in a sealed enclosure will make the sub think that it's in a bigger box..thus gain better sound..i think your bass can get lower too..
David taught me that usin polyfill in a sealed enclosure will make the sub think that it's in a bigger box..thus gain better sound..i think your bass can get lower too..
so the box needs to be stuffed all the way.... ok Ill do that... I have my boxes in my room right now because im waiting for my battery to charge on my drill to get the subs out... I know im lazy... that and I was awaiting a response
They should be stuffed lightly. The "ideal" amount is about 1.5 pounds of polyfill per cubic foot. The stuff is sold in bags marked in pounds, so it's pretty easy to figure out. Just don't pack it in there, that'll be too much. Whatever fits in loosly and easily.
Polyfill can be used in ported boxes. Almost all manufactures suggest some sort of damping material when running ported, usually a sheet or mat attached to the sides of the enclosure (simular to 1-2" thick home insulation, for a visual). I had nothing of the sort, so I very lightly stuffed my enclosure with polyfill. My sub and port are on opposite ends of the box, so I just put the material in the 2/3's that the sub is on. Seems to work fine. I did it on my old box with my JL 8 W-0 and it worked very well, seemed to lower the tuning a noticable amount, gave a stronger low end (I was very surprised, I was just trying it for kicks and grins).
Polyfill can be used in ported boxes. Almost all manufactures suggest some sort of damping material when running ported, usually a sheet or mat attached to the sides of the enclosure (simular to 1-2" thick home insulation, for a visual). I had nothing of the sort, so I very lightly stuffed my enclosure with polyfill. My sub and port are on opposite ends of the box, so I just put the material in the 2/3's that the sub is on. Seems to work fine. I did it on my old box with my JL 8 W-0 and it worked very well, seemed to lower the tuning a noticable amount, gave a stronger low end (I was very surprised, I was just trying it for kicks and grins).
I've never heard that before. Seems by that point the volume of space occupied by the fibers themselves would severly effect the enclosure volume. Hell, to get it that tight you could easily fit 10+ pounds in a 1 ft^3 box, which is WAY too much. I had to make some elbow rest pads for a testing stand at college here. For padding I just grabbed some polyfill I had downstairs. The area I needed to fill was about the size of a fist full of the stuff. I had to pack about a dozen fistfulls into it to get the padding to provide a decent support.SMNW2003 said:
Polyester synthetic fiber has a density of approximatly 100 pounds per cubic foot (if it were compressed into a solid, air-free block). So if you stuff 10 pounds in you just sucked 0.1 ft^3 out of the enclosure, and came no where near the "ideal" 15-20% enclosure volume "increase".
Tom Nuisane (spelling?) conducted a test a while back with the frequency responce of a woofer with different amounts of polyfill in the box. He did everything from no stuffing to (I think) 2 lbs per cubic foot. With about 1.5 pounds per cubic foot the enclosure perfromed as though it were 15% larger, and that was then the primo number. The test is somewhere online, but I cannot recall where.
I added some last night and it ended up sounded like total crap... I mean total crap... so I went back into my truck took the subs and boxes back out, took alot out and left some in there... Much better than before... Now im not so sure that the polyfill is any better than none... I have 2 sony xplode 12's that handle 200 watts rms... This is a temporary system till I get a job and get some Solo Barics. The demensions are... 22 x 16 x 8 The box really isnt even deep enough for the sub magnets so I had to get some half inch plywood and make a speaker ring spacer... Theres enough room for the subs to operate proper though
Is that box size per sub, or for the pair? I'm guessing that's each, because I don't see how you fit a pair of 12's in a 22" width. Is the box angled at all? I can't think of a Sony sub with over 6 inches of mounting depth, let alone 7.25+. Is the box leak free? How much did you stuff in there in the first place? If you had the subs in and out, is there a chance you switched up the polarity and first time and had them running out of phase?
If you are building a ported box you don't want the polyfill near the port. Really you don't want to use polyfill, a filler mat (like insulation) that can be attached to the inside walls of the enclosure is more ideal. You want to keep the stuff away from the voice coil vent as well. Insulating something that dissipates heat isn't a good idea. But basically just fluff it in there through out the box.
If you are building a ported box you don't want the polyfill near the port. Really you don't want to use polyfill, a filler mat (like insulation) that can be attached to the inside walls of the enclosure is more ideal. You want to keep the stuff away from the voice coil vent as well. Insulating something that dissipates heat isn't a good idea. But basically just fluff it in there through out the box.
Peel 'n seal? The stuff I know as peel n seal looks almost like electrical tape, can repair radiator hoses and such when out on the trail. It bonds to itself.
If you are talking something like a dampner similar to Dynamat, then no, I don't feel that would work well in a ported box. Dynamat works by lowering the resonant frequency of a steel surface, making sounds harder to pass through. MDF already has a very low resonant frequency and is good at damping vibrations (hit a piece of sheet metal with a hammer, then a piece of MDF). What the polyfill (or simular) does in a ported box is keeps waves from reflecting off the surface and out the port. Many people use egg-crate acoustical foam inside ported boxes, especially in home theater applications.
If you are talking something like a dampner similar to Dynamat, then no, I don't feel that would work well in a ported box. Dynamat works by lowering the resonant frequency of a steel surface, making sounds harder to pass through. MDF already has a very low resonant frequency and is good at damping vibrations (hit a piece of sheet metal with a hammer, then a piece of MDF). What the polyfill (or simular) does in a ported box is keeps waves from reflecting off the surface and out the port. Many people use egg-crate acoustical foam inside ported boxes, especially in home theater applications.
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