Sealed or lower-tuned ported?

[TheCarFather 10+ year member]

I am looking to "smooth" out my low-end and am looking for suggestions. I did search this topic, but I wanted to find info specific to my sub application, and found nothing.

So heres the deal. I have (2) 12" JBL power series subwoofers installed in a ported enclosure. I had a friend of mine build the box exactly to JBL's specs. The subs are in individual chambers with 1.75 cubes each tuned to 37hz, with the box filled loosely with polyfill. The amp I have on them is sending them ~550W RMS each.

These subs pound pretty hard, and sound decent with the box they are in now. My problem is that I am leaning more towards SQ now, and want to get the most out of my set-up as possible as far as SQ goes. I see a lot of people on here with similar set-ups, and most all have larger boxes than my build. I love the LOW bass, my subs hit them "ok" right now, but not as good as a few sealed boxes I have heard(with diff subs of course).

So my question is, should I build another ported box tuned lower? Or should I go sealed? I have only found a couple reviews on my subs while searching google, and they both said my subs sounded great sealed. I am trying to eliminate the "boominess" my subs have on classic rock and some metal. They sound alright on rap, cuz it's "boomy" in general. I am looking for a tighter, flatter response curve.

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[rollerdj 10+ year member]

I have almost allways used sealed. For the most part very flat response. And if your tight on space, sealed is deffently the way to go.

 

[Notloud00 10+ year member]

if u can try 4 cubes tuned around 29hz

 

[TheCarFather 10+ year member]

I have almost allways used sealed. For the most part very flat response. And if your tight on space, sealed is deffently the way to go.

I have used sealed before in the past as well, and am almost positive I will be happier as far as SQ goes with sealed as opposed to the box I have now.

Although, space is not really an issue. The box is in the trunk of my 01 Focus sedan, and I don't treally lug around much so the box has the trunk all to itself //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif I am mainly interested with what would happen with another ported box tuned lower.

If SQ is my main concern, and I was to go with a lower tuned freq.....should the box be bigger or smaller than it is now? It seems my box is on the small side currently, but it's what JBL suggested(which doesn't always meen it's the best, I know).

Thanks for the opinions so far.....many more encouraged!!!

 

[Immacomputer 10+ year member]

Try plugging your ports right now and see if you like the sound. If not, then try going for a lower tuned enclosure. You can either cover the ports with wood or stuff them tight with towels, either way will give you a good idea of how it will sound sealed.

 

[DidUHearThat? 10+ year member]

+1 Seal the ports with foam rubber to listen, then decide if you like it. Chances are the box you have now is a little too big for sealed, but just adding some poly fill insulation inside might be enough to keep the same box with the ports sealed.

I prefer sealed boxes.

 

[qkassidyw 10+ year member]

+1 Seal the ports with foam rubber to listen, then decide if you like it. Chances are the box you have now is a little too big for sealed, but just adding some poly fill insulation inside might be enough to keep the same box with the ports sealed.
I prefer sealed boxes.

Doesn't poly fill increase the size of the box (or simulate a larger box volume?)

 

[Immacomputer 10+ year member]

Doesn't poly fill increase the size of the box (or simulate a larger box volume?)

It adds damping and lowers the alignment. The same thing happens when you make an enclosure larger but other things happen as well. So no, polyfil does NOT simulate a larger box like people say, but it does do two things that a larger enclosure will do.

And sealed enclosures are very forgiving as far as size is concerned. As you go bigger, you increase low end extension, decrease mechanical power handling, and increase sensitivity. Those changes are very small in small enclosure size steps (say by .25 cubic feet increments) so 1.75 won't be very different from 1.0 or from 2.5.

 

[TheCarFather 10+ year member]

How should I go about sealing up the ports? A lot of air comes out of those, how do I keep something from "blowing" off the port? I understand covering it up, but how do I get the "cover" to stay??

And BTW, thanks for the opinions everyone....

 

[DidUHearThat? 10+ year member]

You just take a peice of foam rubber that is larger than the port and stuff it in the opening until it's sealed up tight. It won't come out until you pull it out.

 

[Immacomputer 10+ year member]

How should I go about sealing up the ports? A lot of air comes out of those, how do I keep something from "blowing" off the port? I understand covering it up, but how do I get the "cover" to stay??
And BTW, thanks for the opinions everyone....

Shove towels in there; they won't blow out or **** in (yes ports pull air in and out) if they're wedged in securely.

 

[tcguy85 10+ year member]

low tuned ported. a low tuned, ported box CAN give you an in car response down to 20hz flat.