poly fill?

[sam_b03 10+ year member]

I have a SA-12 in a sealed box that is 1.25ft predisplacement. I have read that the speaker displaces .14ft. The sub sounds like it needs more air. I heard poly-fill will "trick" the sub into behaving like it is in a bigger box. It is a prefab box what works well in the hatch of my car, and won't be replaced. Curious how much it would help and how much fill I need to use.

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[kramer_212 10+ year member]

thats, and old school trick, but it is now not recomended, by most box builders, your best bet is to get a proper ported enclosure for the best output.

 

[BnGRacing 10+ year member]

I have a SA-12 in a sealed box that is 1.25ft predisplacement. I have read that the speaker displaces .14ft. The sub sounds like it needs more air. I heard poly-fill will "trick" the sub into behaving like it is in a bigger box. It is a prefab box what works well in the hatch of my car, and won't be replaced. Curious how much it would help and how much fill I need to use.

What does "sounds like it needs more air" sound like?

1ft^3 is pretty much the industry standard when it comes to sealed 12's. If your subwoofer is having a hard time playing low, it could be a tuning issue or lack of power. Also, have you checked the terminal cup on your prefab box? Those are notorious for leaking and/or melting when you start pumping a bit of current thru them. A leaky terminal cup can be fixed with silicone, strip caulk, chewing gum, or whatever ghetto material you can find. If there's evidence that it has heated up and is a source of a high resistance, that'll explain the lack of power. Buy a better terminal cup via Parts Express and be done with it.

 

[sam_b03 10+ year member]

What does "sounds like it needs more air" sound like?
1ft^3 is pretty much the industry standard when it comes to sealed 12's. If your subwoofer is having a hard time playing low, it could be a tuning issue or lack of power. Also, have you checked the terminal cup on your prefab box? Those are notorious for leaking and/or melting when you start pumping a bit of current thru them. A leaky terminal cup can be fixed with silicone, strip caulk, chewing gum, or whatever ghetto material you can find. If there's evidence that it has heated up and is a source of a high resistance, that'll explain the lack of power. Buy a better terminal cup via Parts Express and be done with it.

I will check that out. I kow the sa-12's respond better to ported but it isn't a option right now. It is powered by a MB Quart Onyx 1500.1. wired 2ohm so should be 1000rms. It hit looks like it is hitting hard but the volume isn't really there.

Here is what I am working with. I swapped out he IDQ for the Sa-12.

 

[BnGRacing 10+ year member]

Here is what I am working with. I swapped out he IDQ for the Sa-12.

Why the downgrade?

The IDQ is a very efficient light coned woofer...pretty much the opposite of what you're trying to power now. It's why most people recommend huge vented boxed and gobs of power for them. If I were in your situation and was looking for an uber woofer to use in that enclosure, I would have pulled the trigger on an IDMAX and mount it inverted so the magnet sticks out.

 

[BnGRacing 10+ year member]

Here is what I am working with. I swapped out he IDQ for the Sa-12.

Why the downgrade?

The IDQ is a very efficient light coned woofer...pretty much the opposite of what you're trying to power now. It's why most people recommend huge vented boxed and gobs of power for them. If I were in your situation and was looking for an uber woofer to use in that enclosure, I would have pulled the trigger on an IDMAX and mount it inverted so the magnet sticks out.

 

[sam_b03 10+ year member]

I was liked how musical the IDQ was but I wanted a little more impact on the low notes. I kept hearing about how the Sundowns are able to be used SQ but hit a little harder. I wanted to try it. I think my mids would drown out the ID now. I have thought about switching back. I really don't want to have change out my amp. Since it is screwed down to the box, I don't to punch a bunch of holes in it. I have the amp set so there the crossovers are open and am using the HU xover at 63hz. It's Pioneer 3300bt. I don't know what the slope is.

The IDMAX is kinda out of my price range.

 

[schackel 10+ year member]

thats, and old school trick, but it is now not recomended, by most box builders, your best bet is to get a proper ported enclosure for the best output.

false. most companies that make boxes for their subs have a **** load of poly fill in them.

 

[kramer_212 10+ year member]

false. most companies that make boxes for their subs have a **** load of poly fill in them.

Sorry (for properly made enclosures )

 

[whitedragon551 5,000+ posts]

thats, and old school trick, but it is now not recomended, by most box builders, your best bet is to get a proper ported enclosure for the best output.

Where did you hear that? I would always build my box a little smaller than needed and use polyfill. Not only does it trick the sub into thinking its in a larger box it also smooths out the impedance rise.

 

[kramer_212 10+ year member]

Where did you hear that? I would always build my box a little smaller than needed and use polyfill. Not only does it trick the sub into thinking its in a larger box it also smooths out the impedance rise.

Well fuqq me

 

[snyderd758 10+ year member]

I use 1lb per cubic foot it definetely helps with sealed in my experience no matter if the enclosure is the proper volume or not. In a little bit of a side bar i tried it in a ported enclosure and it sounded like ***. I have the pioneer 4300 and the crossovers are 12db slopes you amps crossover would probably be more precise and 63hz is pretty low for one 12 try to set it around 80 or if you can have a friend sit in the back seat and adjust til it sounds the best to you. Check your subsonic filter too i dont think its defeatable on that amp just set it to the lowest setting.

 

[schackel 10+ year member]

Well fuqq me

herd dat

 

[sam_b03 10+ year member]

It's a two seater. No back seat. I set it at 63 because I jerrry-rigged my comps. I bought a 3way because it was a good deal. I couldn't fit my 4in mid in door. It got mounted on the B-pillar. The 6.5 mid was crossed over so low I lost alot of sound. I now have the 6.5 seeing full range and turned down the level on the 4in. I am satisfied with the mids now. The passive Xovers are set at 55htz to the mid. My HU goes from 50,63,80,125. I have the Hpass set at 63 for the mids and 63LP on the sub. I will play around with the setting a little more.

I didn't trust the amp crossovers because I didn't know how accurate they would be. I know the grain labels aren't the trustworthy.

 

[KTMrida4life 10+ year member]

I say stuff a ton of polyfill in there and see what happens.

It for sure helped my old Kenwood subs when they were in a sealed box. Doesnt compare to what Im running now.. but they were pretty loud for what they cost me at the time.