Firm believer in poly-fill

[80_Cutlass_mn 10+ year member]

Well today I helped a buddy of mine install a IA 187 10 with a Crossfire VR1000D at 2 ohms in a standard cab f-150. We bought a premade box of about 1 cu. ft. and filled it lightly with poly-fill. Maybe about 1/4 of a pound and he let me have the rest. Well the install went well and sounded great so he was happy. As for me, I got curious and put the rest which was about 1 pound inside my 1.5 cu ft. sealed box for my DP. Before you could here what I thought was the sound of my BX1000D clipping but in fact it wasnt. It was distortion caused by so much pressure inside the box forcing itself against the cone. After the poly-fill I tryed it out and immediately noticed it would play deeper notes and thought well hmm...this is interesting. So I cranked it on up to what was normally thought to be clipping level but it still played clear as a whistle so I cranked the pre-outs on my deck up to max and tryed it again. Let me just say this thing will now play low notes with some authority. Before you could tell the sub was just really restricted on sub 40hz frequencies, not anymore. It can now render my rear view mirror useless below 40 hz and make you feel it in your chest. Its really amazing what a little poly-fill can do.

Final words...If you have a sealed box and think your sub-amp can do more but feel the box is restricting you....try poly-fill. It might do more than you think.

I understand some of you might raise the //content.invisioncic.com/y282845/emoticons/bsflag.gif.21f42eccd34b7d1eb1608fb1b59b69c3.gif but I can honestly say I havent heard such a diff except from going from sealed to a crappy made ported box. Anyway, this was my experience, im sure results will vary.

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[Curel 10+ year member]

Glat to hear. I wonder if polyfill can be used to shrink down air space. Anybody have any idea?

 

[jjski78 10+ year member]

Glat to hear. I wonder if polyfill can be used to shrink down air space. Anybody have any idea?

No it can't. What poly-fill does is slow down the soundwaves inside the box. It basically makes the box seem bigger to the sub. So your sub performs as if it was in a bigger enclosure.

 

[PhatTonyDeMarco 5,000+ posts]

Glat to hear. I wonder if polyfill can be used to shrink down air space. Anybody have any idea?

No, when polyfill is added the subwoofer will act as if there was more volume added to the enclosure.

-jjski was a tad faster //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[dalucifer 10+ year member]

fiberglass insulation works great...

 

[9512ds 5,000+ posts]

Glat to hear. I wonder if polyfill can be used to shrink down air space. Anybody have any idea?

just glue down some spare pieces of wood to shrink the enclosure size down

 

[Curel 10+ year member]

I know it's mainly used to make subs think there in a bigger box, but wonder if it can also be used to shrink down some air space. I remember reading that it can be used by someone reputable, maybe even an admin.

just glue down some spare pieces of wood to shrink the enclosure size down

Yeah, I have some wood cut already, but trying to avoid this process if at all possible.

 

[GrnEydDvl 10+ year member]

I know it's mainly used to make subs think there in a bigger box, but wonder if it can also be used to shrink down some air space. I remember reading that it can be used by someone reputable, maybe even an admin.

Why would you try to use it for the opposite of what it does do?

Do not use polyfill to "shrink down space" or to make the internal volume smaller. Use solid objects like wood for that.

 

[Curel 10+ year member]

Why would you try to use it for the opposite of what it does do?
Do not use polyfill to "shrink down space" or to make the internal volume smaller. Use solid objects like wood for that.

I'm not adding any polyfill, just inquiring about it. like I said, this came from somebody reputable.

 

[Curel 10+ year member]

Why would you try to use it for the opposite of what it does do?
Do not use polyfill to "shrink down space" or to make the internal volume smaller. Use solid objects like wood for that.

Am I reading this wrong or are you a cocky sob?

*Edit*

Nah, i'm reading it wrong. My bad.

 

[mtdewelf 10+ year member]

Am I reading this wrong or are you a cocky sob?

no, he's restating something that's been told to you. it slows the waves down in the box, that makes the waves take longer to reach walls making the box seem bigger. I suppose if you wrap abunch of polyfil in tape and make a little cotton brick it'll do what you want

 

[Curel 10+ year member]

I know what pollyfill does, just wondering if it would also take up space as previously suggested in another forum. I guess it won't. Thanks.

 

[supraman1379 10+ year member]

I put some polyfil in the first box I had for my 12s. It made a noticable difference. I believe in using it. I just dont think you can use it in a vented enclosure.

 

[thch 10+ year member]

poly absorbs energy. IIRC the Qa or Ql property in winISD can be changed to model the effect. i think its Qa. not sure what fill densities correspond to what value of Q though.