Sub box size effects?

(juice75) · (juice75) **Join Date: Jul 2004** 05-09-2005, 8:00 AM

What is the effect of having too much airspace in a sealed sub box? How about to little? This is for a 10" sub, if it matters.

(boarditup) · (boarditup) **Join Date: Jan 2004** 05-09-2005, 8:57 AM

Almost impossible to have too much enclosure. Rockford Fosgate has a calcuation guide that is excellent.

(jklein) · (jklein) **Join Date: May 2001** 05-09-2005, 9:01 AM

I have a 10 in my boat and found that I at first stuffed it too full with baffle material. It's in a QLogic 10 inch box. You can look up the specs online to determine the volume of the box, but I think's it's 1 cubic foot.

Anyway, it was muffled and didn't sound so good. I took out most of the baffle material, and use only 1 layer of the material now. I used spray adhesive to stick it to the walls on the inside of the box. all around all 5 exposed sides.

It's now very punchy and clear. It's also not ported. It's sealed. I'm no expert, but that was my experience.

(juice75) · (juice75) **Join Date: Jul 2004** 05-09-2005, 9:07 AM

I may try that. The box I built is .7 cubic feet (manufacturer's spec), 3/4" MDF, and the sub seems muffled, not punchy at all. I'll play around with baffle material, and see if that makes a difference. There's none in there right now.

(jklein) · (jklein) **Join Date: May 2001** 05-09-2005, 9:30 AM

I hear that you need some baffle material to deflect the sound waves. If you don't have it the sound waves will bounce off the box and hit the speaker causing it to go out of sync. This causes distortion. The material absorbs the shock. That's probably why they also make the boxes at an angle to deflect the waves around the box vs directly back at the speaker.

(magic) · (magic) **Join Date: Mar 2002** 05-09-2005, 10:13 AM

Typically a smaller sealed box will do a few things for a sub.
1. Have a puncher/thighter sound
2. Increase power handling and increase how much power you'll need for the same spl.
3. Decrease how low the sub will play.

When you fill the box with stuffing/polyfill it makes the box behave like it's slightly larger in volume and reduces standing waves in the box. So when you take out some of the polyfill and the sub sounds better you balanced out the behavour of the box/sub/power/enviornment better.

I'd start with what the sub maker suggests and go from there. Keep in mind that boats are going to require more work to get that same boomy sound that cars can get. The inside of a car acts like an other enclosure which increases the spl for bass freq. Ski boats will not have this same cabin gain