Subwoofer Insulation

Early B. · 11-28-2005, 05:46 PM

I read Gaara's thread re: tweaking his Supernova with Dynamat and it got me thinking about subwoofer insulation. What is the best way to insulate a subwoofer?

I used a generous amount of inexpensive wave style foam in my sub (see pic).
I'm wondering if Dynamat or some other type of insultation would work better. I also heard that using peel-n-stick floor tiles work well, too. Very cheap.

Also, how much insulation do you add? In the SVS I used to own, there was only a smattering of insulation, but in the one I built, I covered up 80% of the interior walls. Should I re-do my work????

Thanks.

Dennis Gardner · 11-28-2005, 05:53 PM

Sub insulation is less important than wall flex. With that said, I covered the walls of mine with open cell foam about 2 inch thick.

tryrrthg · 11-28-2005, 06:21 PM

The insulation in your SVS was most likely there to "fool" the driver into "thinking" the enclosure is bigger than it is. From what I've read polyfil or fiberglass insulation are the best things to stuff subs with. The stuffing are also in there to absorb high frequency info that passes through the crossover. Dynamat would only help with cabinet resonances, you would still want some stuffing in your enclosure.

Here is a good discussion on stuffing

I'm still trying to find a good article on stuffing...

Vr3MxStyler2k3 · 11-28-2005, 06:32 PM

I am an advocate of FOAM... (as you already know)

That Sonicbarrier stuff on PE, although expensive is awesome. I'm being serious... very dense foam.

Their other type of eggcrate foam is alot different than regular egg crate and is also very dense....

Foams does what Polyfill does - and it also dampens the panel (when coupled to the panel) - so I think its better.

tryrrthg · 11-28-2005, 07:07 PM

That's the thing, I wouldn't want something very dense. The two things you want stuffing to do is absorb high frequency info that makes it through the crossover and make the enclosure "appear" larger by slowing down the air inside. something dense will just reflect high frequency info and actually take up enclosure volume because it's too dense for the air inside the enclosure to pass through. I could however see the merits of it on the enclosure walls.

Early B. · 11-28-2005, 07:23 PM

I pulled the most salient quotes from the link given:

"Ported boxes are lined with damping material, sealed boxes are stuffed at a rate of 0.5-1.5 lb/cu ft."

"Start with 1 lb/cu ft. Then add more damping in 1/4 lb increments, as long as the bass continues to 'tighten' add more damping. At the point where the bass no longer tightens, and the only effect is a drop in the overall output level, remove the last amount of damping added."

"A few rules of thumb: Stuff small enclosures – those with up to about 3 cubic feet of internal volume or less – with 1.5 pounds of fiberfill for each cubic foot of internal volume and you should get about a 30-percent increase in box volume without seriously affecting other performance variables. For larger enclosures, add stuffing at a rate of approximately 1 pound per cubic foot and you should get a virtual-space boost of about 25 percent."

Early B. · 11-28-2005, 07:30 PM

Thanks for the info, fellas. I suppose I'm OK with what I did. Here's a link to the pics of the sub while it was being built. It shows the amount of foam I added. The foam is about 1 inch thick and is not very dense.

http://www.polkaudio.com/forums/show...ight=Atlas+DIY

Vr3MxStyler2k3 · 11-28-2005, 08:02 PM

Its not THAT dense... it will allow sound to pass through it very easilly - its just not a lightweight material like polyfill...

The Eggcrate foam PE sells, although denser than regular eggcrate foam is a nice material to use... the sonic barrier stuff is designed specifically for what you're talking about though.

madmax · 11-29-2005, 05:29 PM

Quote:

Originally Posted by Vr3MxStyler2k3

I'm being serious...

You have been very serious lately Sid Serious.

madmax

Vr3MxStyler2k3 · 11-29-2005, 05:52 PM

Im seriously not serious this time that Im serious...

That would make me seriously unserious... seriously... this is retarded.

11-28-2005, 05:46 PM	#1
Early B. Polk Guru Member Sales Rating: (19) Join Date: Sep 2003 Posts: 8,172	Subwoofer Insulation I read Gaara's thread re: tweaking his Supernova with Dynamat and it got me thinking about subwoofer insulation. What is the best way to insulate a subwoofer? I used a generous amount of inexpensive wave style foam in my sub (see pic). I'm wondering if Dynamat or some other type of insultation would work better. I also heard that using peel-n-stick floor tiles work well, too. Very cheap. Also, how much insulation do you add? In the SVS I used to own, there was only a smattering of insulation, but in the one I built, I covered up 80% of the interior walls. Should I re-do my work???? Thanks. Attached Thumbnails __________________ HT/2-channel Rig: Sony 50” LCD TV; Toshiba HD-A2 DVD player; Emotiva LMC-1 pre/pro; Rogue Audio M-120 monoblocks (modded); Placette RVC; Emotiva LPA-1 amp; Bada HD-22 tube CDP (modded); VMPS Tower II SE (fronts); DIY Clearwave Dynamic 4CC (center); Wharfedale Opus Tri-Surrounds (rear); and VMPS 215 sub "God grooves with tubes."

11-28-2005, 06:21 PM	#3
tryrrthg Polkhead Member Sales Rating: (11) Join Date: Jul 2001 Location: Columbus, Ohio Posts: 1,799	The insulation in your SVS was most likely there to "fool" the driver into "thinking" the enclosure is bigger than it is. From what I've read polyfil or fiberglass insulation are the best things to stuff subs with. The stuffing are also in there to absorb high frequency info that passes through the crossover. Dynamat would only help with cabinet resonances, you would still want some stuffing in your enclosure. Here is a good discussion on stuffing I'm still trying to find a good article on stuffing... __________________ The Had My First Child, Have To "Give Up" My Stereo Room, Condensed Two Channel & HT Rig: Mains: Dynaudio Focus 140 Integrated Amp: Arcam A85 Source: Slim Devices Squeezebox 3 -> Bel Canto DAC 1.1 Home Theater: Sony KDL-40V2500 HDTV, Sony BDP-S550 Blu-ray, Polk CSi3 & R15, Denon 2802 receiver, and DIY sub with Atlas 15

11-28-2005, 06:32 PM	#4
Vr3MxStyler2k3 Sid the Kid Member Sales Rating: (21) Join Date: Mar 2003 Location: NC Posts: 15,664	I am an advocate of FOAM... (as you already know) That Sonicbarrier stuff on PE, although expensive is awesome. I'm being serious... very dense foam. Their other type of eggcrate foam is alot different than regular egg crate and is also very dense.... Foams does what Polyfill does - and it also dampens the panel (when coupled to the panel) - so I think its better. __________________ Da Rig- Mains- Tyler Acoustics Super Towers Subwoofer- Tyler Acoustics Custom Seas 10" Stereo Subs Amplifier- Odyssey Stratos Extreme Mono Blocks Preamp- Odyssey Candela CD Player- Symphonic Line Vibrato The CD Player Power Conditioner- MIT Z Center Speaker Cables- MIT Shotgun S2 Bi-Wire Signal Cables- MIT Shotgun S2 Subwoofer Cables- MIT AVT 1 Power Cables- MIT Shotgun AC1 (Amps/Pre/CDP) MIT Z Cord II (Conditioner/Subs) Polks are in the truck!

11-28-2005, 07:30 PM	#7
Early B. Polk Guru Member Sales Rating: (19) Join Date: Sep 2003 Posts: 8,172	Thanks for the info, fellas. I suppose I'm OK with what I did. Here's a link to the pics of the sub while it was being built. It shows the amount of foam I added. The foam is about 1 inch thick and is not very dense. http://www.polkaudio.com/forums/show...ight=Atlas+DIY Last edited by Early B.; 11-28-2005 at 07:33 PM..

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11-28-2005, 05:53 PM	#2
Dennis Gardner Polkologist Member Sales Rating: (1) Join Date: Dec 2003 Location: Sooner Country Posts: 3,468	Sub insulation is less important than wall flex. With that said, I covered the walls of mine with open cell foam about 2 inch thick.

11-28-2005, 07:07 PM	#5
tryrrthg Polkhead Member Sales Rating: (11) Join Date: Jul 2001 Location: Columbus, Ohio Posts: 1,799	That's the thing, I wouldn't want something very dense. The two things you want stuffing to do is absorb high frequency info that makes it through the crossover and make the enclosure "appear" larger by slowing down the air inside. something dense will just reflect high frequency info and actually take up enclosure volume because it's too dense for the air inside the enclosure to pass through. I could however see the merits of it on the enclosure walls.

11-28-2005, 07:23 PM	#6
Early B. Polk Guru Member Sales Rating: (19) Join Date: Sep 2003 Posts: 8,172	I pulled the most salient quotes from the link given: "Ported boxes are lined with damping material, sealed boxes are stuffed at a rate of 0.5-1.5 lb/cu ft." "Start with 1 lb/cu ft. Then add more damping in 1/4 lb increments, as long as the bass continues to 'tighten' add more damping. At the point where the bass no longer tightens, and the only effect is a drop in the overall output level, remove the last amount of damping added." "A few rules of thumb: Stuff small enclosures – those with up to about 3 cubic feet of internal volume or less – with 1.5 pounds of fiberfill for each cubic foot of internal volume and you should get about a 30-percent increase in box volume without seriously affecting other performance variables. For larger enclosures, add stuffing at a rate of approximately 1 pound per cubic foot and you should get a virtual-space boost of about 25 percent."

11-28-2005, 08:02 PM	#8
Vr3MxStyler2k3 Sid the Kid Member Sales Rating: (21) Join Date: Mar 2003 Location: NC Posts: 15,664	Its not THAT dense... it will allow sound to pass through it very easilly - its just not a lightweight material like polyfill... The Eggcrate foam PE sells, although denser than regular eggcrate foam is a nice material to use... the sonic barrier stuff is designed specifically for what you're talking about though.

11-29-2005, 05:52 PM	#10
Vr3MxStyler2k3 Sid the Kid Member Sales Rating: (21) Join Date: Mar 2003 Location: NC Posts: 15,664	Im seriously not serious this time that Im serious... That would make me seriously unserious... seriously... this is retarded.

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