poly fill in a sealed enclosure...question

[Amish Marauder 0]

Hey everyone. I have a sealed enclosure with 1 SS RL-p 15 d2. The internal air space is 2.25 cu. ft.

I have a Directed 1500D hooked up to it putting 1100wrms @ 1ohm

It sounds amazing now that I set the amp up properly. I'm very happy.

Now to the question:

I have two 1 lb bags of poly fill. By tossing both bags in the enclosure it would trick the sub into thinking its in a 2.7 cu. ft. box (round about).

I was wondering what effect you think this would have on the sound? I don't want to pull my sub out and try it if its not going to do anything for my setup. What do you guys think would happen sq wise and output wise?

[Aaron Clinton 2,372]

not sure how it will react sound wise, but I worry about power handling

[Amish Marauder 0]

worry about power handling? How so? if you don't mind explaining.

Are you saying that with a larger sealed enclosure it would take more power to run the sub properly?

[Aaron Clinton 2,372]

from my experience, subs when placed in large sealed boxes tend to have lower power handeling, I know the RL-p is a strong sub, but its specs favor ported boxes so I am not sure how it will react going large sealed, or tricking it into large sealed

[Amish Marauder 0]

Well I don't need to do this. I just was thinking about the two bags of poly fill I have just sitting there.

[Aaron Clinton 2,372]

Well I don't need to do this. I just was thinking about the two bags of poly fill I have just sitting there.

Mike would probably know better than I on this, not sure if he has tested it sealed with some polyfill at that size enclosure

[tRiGgEr 0]

Only thing I see you gaining is a bit of low end extension. This is normally the only reason to add polyfill. When your space is limited and you can't build a larger box. It will help the speaker perform like it would in the larger box.

In a larger box power handling would be decreased. It will not take as much power to reach full motion.

tRiGgEr

[///M5 2,833]

Being the subs "optimal" enclosure size is where you started I don't think you will gain anything. Also, as Denim states the power handling of the sub goes down the larger the enclosure you put it in which might make you lower where your gains are set to keep from damaging the driver--of course it might be fine as adding the amount of "perceived" airspace by stuffing might not make all that much difference. It will make the sub feel like it is in a larger box, but maybe not that much larger.

I guess, I wouldn't bother but it isn't that hard to yank the sub and try it out.

[Amish Marauder 0]

very true. I don't think I'll bother. I actually like the sound I'm getting and it really hits the low deeeeep bass well. its the higher Hz bass notes it doesn't seem to like as much.

[SoundSplinter 1]

Well polyfill ain't gonna help your top end extension.. nevertheless and as M5 noted, it isn't too difficult to try out (unless you're worried about stripping your screw holes on the baffle - another win for the T-nuts!). Some people enjoy the fill, some don't -- but given the size of your enclosure, I don't think it's necessary by any means.

As for your crossover point.. In my experience, I prefer between 60 - 80 Hz on down.

[Amish Marauder 0]

good stuff, thanks everyone.

[idiot 7]

... but given the size of your enclosure, I don't think it's necessary by any means.

Agreed. 2.25 cu.ft is a perfect fit for my RL-p15. I'd compare my sealed box to a vented one if I had the room and skill to slap an internal port on a curved surface. It would likely get a bit louder, but I have severe doubts that it would sound better, even at lower frequencies.

Amish, if you're worried about upper extension, can you tell us what midrange driver you're running? As Mike said, the crossover point should be between 60-80Hz (much closer to 60Hz, if possible). If you're getting poor midbass performance, I would look at your other drivers (and their x-over settings) before the sub.

[Amish Marauder 0]

My mid-bass drivers aren't installed yet. I bought DYNAUDIO system 260's (two 8" mids and two 1.1" tweets w/ xovers) An Orion 8004 will power them.

As of right now I'm running factory speakers through out the car except for the sub of course. In a couple weeks I'm having my front doors fiberglassed and then I can put those Dynaudio's to the test.

Edited February 23, 2006 by Amish Marauder

[idiot 7]

Those Dyns should definitely be able to get down to 60Hz. Cross them low, and your upper bass/midbass worries should vanish. It should sound great when everything is all set up. Let us know how the install goes.

[Amish Marauder 0]

Thanks I will. Yeah I'm betting those Dyn's will pull everything together.

[///M5 2,833]

Most def will.