Why the polyfil??
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Road Master
Joined: May 2008
Posts: 997
Likes: 96
From: Channahon, IL.
Why the polyfil??
Posted this in another polyfil thread but it hasn't received an answer so I thought I'd post it as it's own question.
I ask for the sake of expanding my own knowledge base...yeah, I'm as shocked as anyone, lol. I remember in HS seeing subwoofer enclosures having different types of insulation in them so I know it's been being done for years and I'm sure there's a reason. My question is what is that reason? What's the science behind it? How does it effect speaker response and performance? I'm sure those who've tested this themselves with o-scopes and the like or have read other results will have the info on this. Thanks!
I ask for the sake of expanding my own knowledge base...yeah, I'm as shocked as anyone, lol. I remember in HS seeing subwoofer enclosures having different types of insulation in them so I know it's been being done for years and I'm sure there's a reason. My question is what is that reason? What's the science behind it? How does it effect speaker response and performance? I'm sure those who've tested this themselves with o-scopes and the like or have read other results will have the info on this. Thanks!
Club Member
Joined: Jul 2014
Posts: 11,460
Likes: 3,554
From: Idaho
You only want the "good" sound out of a speaker enclosure.
All enclosures have the two problems (some worse than others) of resonance and reflection:
Ideally a speaker enclosure is utterly rigid, but all enclosures tend to flex a tiny bit.
Plus, the sound from the driver reflects around the inside of the enclosure.
These two unwanted acoustic effects, the flexing or vibration of the enclosure at certain resonant frequencies, plus the internal reflection of the sound, all make the speaker sound bad.
Filling the inside of the enclosure makes a huge improvement because it dampens or deadens these unwanted sounds. In high fidelity speaker enclosures the type of fill is carefully chosen and the amount put into the enclosure is carefully measured in order to get the most optimal results.
Hope that helps!
All enclosures have the two problems (some worse than others) of resonance and reflection:
Ideally a speaker enclosure is utterly rigid, but all enclosures tend to flex a tiny bit.
Plus, the sound from the driver reflects around the inside of the enclosure.
These two unwanted acoustic effects, the flexing or vibration of the enclosure at certain resonant frequencies, plus the internal reflection of the sound, all make the speaker sound bad.
Filling the inside of the enclosure makes a huge improvement because it dampens or deadens these unwanted sounds. In high fidelity speaker enclosures the type of fill is carefully chosen and the amount put into the enclosure is carefully measured in order to get the most optimal results.
Hope that helps!
Last edited by IdahoHacker; Dec 5, 2014 at 01:26 PM.
Ultimate HDF Member
Joined: Oct 2012
Posts: 6,621
Likes: 412
From: Indianapolis IN.
Posted this in another polyfil thread but it hasn't received an answer so I thought I'd post it as it's own question.
I ask for the sake of expanding my own knowledge base...yeah, I'm as shocked as anyone, lol. I remember in HS seeing subwoofer enclosures having different types of insulation in them so I know it's been being done for years and I'm sure there's a reason. My question is what is that reason? What's the science behind it? How does it effect speaker response and performance? I'm sure those who've tested this themselves with o-scopes and the like or have read other results will have the info on this. Thanks!
I ask for the sake of expanding my own knowledge base...yeah, I'm as shocked as anyone, lol. I remember in HS seeing subwoofer enclosures having different types of insulation in them so I know it's been being done for years and I'm sure there's a reason. My question is what is that reason? What's the science behind it? How does it effect speaker response and performance? I'm sure those who've tested this themselves with o-scopes and the like or have read other results will have the info on this. Thanks!
How are you liking the Polks Mike?
Supporter
Joined: Feb 2008
Posts: 4,133
Likes: 147
From: Grays Creek, NC
I'm still playing around with mine but just installed two 15x15 sheets per 7.1 in the fairing to see if it helped any. To me it doesn't sound as good, like I lost bass? None of the polyfil is in the speaker just wrapped around the bracket as advised. Maybe I just need to tweak my audio setting some more but it sounded real good before and I thought "why not". If I can't get it the way it was or better its too easy to remove and I'm only out $5.
Supporter
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From: Grays Creek, NC
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Cruiser
Joined: Jul 2010
Posts: 179
Likes: 1
From: Coastal Georgia
Gannicus. Can you post a pic of how the poly fill should look installed? My speakers, amp shipped out this morning�� next week should be singing��
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From: Indianapolis IN.
Dam it man! I would have to take my fairing off for the zillionth time. . .lol There are a bunch floating around the forum I just have to find them. I think my friend AAWAV has some pics and I know NUTZ does. He's got pics of everything you can think of. . . lol
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