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gellin
Member
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Poly-Fil
i'm planning on building my own box this weekend and i was wondering if this poly-fil stuff is worth buying.i have two kicker 10" L7's solo barics.
http://www.crutchfield.com/S-Sbcvtl4YRMa/cgi-bin/ProdView.asp?g=741&I=027808&id=review
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 02-07-2006 09:13 AM |
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dyedef1966
Member
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Poly fill should be installed in EVERY sub box. at least 1" thick on all sides. I wouldn't buy it on there, though. Go to wal-mart or something, and buy a cheap-ass pillow. Exact same shit inside.
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| 02-07-2006 09:20 AM |
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Donsway
Member
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Only time that I have not used it was on the boxes I have now. Powerbass says when going for SPL and box is tuned high (mine 54Hz) no poly fill, but this is only time I have seen this.
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| 02-07-2006 10:16 AM |
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Ryan21
Member
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If your box is built to spec you shouldn't need poly-fill. It is a good alternative when you box is to small for your drivers.
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| 02-07-2006 10:29 AM |
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dyedef1966
Member
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I gotta disagree, Ryan. Boxes without poly-fill are said to sound "hollow". Poly-fill helps to absorb standing waves, and unwanted resonances.
I do agree with the fact that overfilling your box can actually "fool" the speaker into thinking it has a bigger internal volume, though, to a certain %. Just my opinion, and everybodys got one.
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| 02-07-2006 10:54 AM |
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squeak9798
Member
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RE:
quote:
Originally posted on 02-07-2006 by dyedef1966
I gotta disagree, Ryan. Boxes without poly-fill are said to sound "hollow". Poly-fill helps to absorb standing waves, and unwanted resonances.
I do agree with the fact that overfilling your box can actually "fool" the speaker into thinking it has a bigger internal volume, though, to a certain %. Just my opinion, and everybodys got one.
FYI: Standing waves in a subwoofer enclosure are 100% a non-issue. The wavelengths are entirely too long in relation to the enclosure size for standing waves to be a problem. There is no opinion about this...it's an absolute fact. Standing waves are completely irrelevant and a complete non-issue for subbass in any enclosure small enough that it will fit into a vehicle. The enclosure would need to have side-walls tens of feet by tens of feet before standing waves for subbass would ever be an issue.
Likewise, the foam/polyfil/etc would have to be multiple feet thick to actually absorb subbass waves. Sticking 1 or 2 inches of polyfill on a side wall is not going to do anything as far as absorption of soundwaves is concerned. Again, no opinion necessary...this is a fact.
Polyfill is NOT necessary in every enclosure. Absolutely not. If your enclosure is adequately sized, there is no need for it at all.
If you added polyfil and heard a difference in sound, then the difference was likely due to the increased acoustic compliance of the enclosure (as a result of the polyfill) and not because of the factors you mentioned. Essentially, you heard the subwoofer perform as if it were in a slightly larger enclosure, and you preferred that sound more. All that tells you is that you could have built the enclosure slightly larger and arrived at the same results (without using polyfill).
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| 02-07-2006 11:47 AM |
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Ryan21
Member
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dyedef1966, I am not disagreeing with you, everyone has there own ways and preferences. I would use poly-fill if a box sounded to "boomy" for the users preference. other than that, i probably wouldn't
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| 02-07-2006 12:19 PM |
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Donsway
Member
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The way I see it is that the box is the hardist and most important part of a system to get right. You should try different things, poly fil is cheap put it in try, don't work take it out. I just rebuild the box and try it out, but maybe I can get 1dB out of this design build it try. Each car does it's on thing on sound so you just have to try if you want the most it can give.
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| 02-07-2006 03:58 PM |
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dyedef1966
Member
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Like I said, My opinion. But Gellin, before you make a decision, search around the net a little more. a had a few extra minutes, so I did a little for you. you might want to check out......www.the12volt.com/caraudio/boxes.asp as well as www.carstereo.com/help/box_build.cfm and last diyaudiocorner.tripod.com/faq On that one, scroll down to find the question "Do I really need acoustic insulation in my subwoofer box"
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| 02-07-2006 07:42 PM |
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squeak9798
Member
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RE:
quote:
Originally posted on 02-07-2006 by dyedef1966
Like I said, My opinion. But Gellin, before you make a decision, search around the net a little more. a had a few extra minutes, so I did a little for you. you might want to check out......www.the12volt.com/caraudio/boxes.asp as well as www.carstereo.com/help/box_build.cfm and last diyaudiocorner.tripod.com/faq On that one, scroll down to find the question "Do I really need acoustic insulation in my subwoofer box"
Most of the info given in that "Do I really need acoustic insulation in the box" (it does not state in my subwoofer box) applies to full range drivers, but NOT to subwoofers. There is a HUGE distinction to be made there. Though even then it's only partially correct on some of it, even when applied to full range drivers.
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| 02-07-2006 08:42 PM |
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dyedef1966
Member
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LOL Yet the other 2 sites you didn't mention (one of which you are on right now) are VERY specific when they state that they are speaking of Subwoofer boxes for "Car Audio". One says it is recommended, the other says they advise it, which is what I did. I recommended it. I don't understand...why so argumentative??
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| 02-08-2006 05:18 AM |
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cmeace
Member
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I'm by no means an expert. However, in the 17 years that I have been doing this, Poly-fil in a box is almost a standard. It is personal preference, but all enslosures that I have built and most of the ones I've seen built by others have some in it. I can definitely tell a difference when you play around with how much you choose to use. Donsway has a point, it's a cheap and easy experiment, if you don't like it, simply take it out. Dyedef has referenced you some good articles. It seems to be a consensus.
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| 02-08-2006 08:51 AM |
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squeak9798
Member
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RE:
quote:
Originally posted on 02-08-2006 by dyedef1966
LOL Yet the other 2 sites you didn't mention (one of which you are on right now) are VERY specific when they state that they are speaking of Subwoofer boxes for "Car Audio". One says it is recommended, the other says they advise it, which is what I did. I recommended it. I don't understand...why so argumentative??
I'm not arguing that it isn't something you can play around with, and I'm not saying it has zero effect.
What I am trying to make you understand is the principles behind why it has an effect on the sound (because it's not for the reasons you have been mentioning), and that it is not a requirement in an enclosure that is adequately sized for your taste. Simply "recommending" someone try playing with it is different than saying it "should be in EVERY enclosure" (which was your exact original statement). It is not a *must*, but it's something you can play around with. And it does not have an effect on sound because of standing waves, etc, like you mentioned earlier.
I didn't mention the other two links because frankly, I didn't visit those links and didn't feel like it...LOL I went to the last one you mentioned because you had a specific section pointed out in it to read (so I didn't have to waste time reading the entire link).
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| 02-08-2006 10:05 AM |
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squeak9798
Member
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RE:
quote:
Originally posted on 02-08-2006 by dyedef1966
Maybe you SHOULD read more! lol
I don't get it.......
Anyways, do you understand my points (my first post in this thread)? Or was it all in vain and you are going to continue preaching the (inaccurate) standing waves/etc reasoning?
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| 02-08-2006 12:34 PM |
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