Alright, I have two 10" SI BMs I am putting in a sealed box. I am doing 1.499cuft after displacement if I do common chamber, so around .7cuft each or a tad less if I do individual chamber. Should I be doing individual or common? Are there benefits to one over the other? How about poly-fill? Necessary/helpful in this case? Thanks guys, I appreciate it!
with individual chambers you can still run your setup if one of your subwoofers blows or has a mechanical malfunction. if you have a common chamber and one of your subs breaks, then you will have 1 bm in a 1.5 cubic foot sealed enclosure. im sure that wouldnt be that bad, but it wouldnt be what you planned on putting it in.
Ive heard sound does change a little from common to individual. Ive also always heard when doing sealed to do individal chambers and add in polyfill. My dual revo box was shared chamber without polyfill and it sounded amazing tho.
Well... it isn't as simple or cut and dried as some may think. There are advantages to both configs. The main advantage of separate chambers is what Gibson mentioned above as well as the fact that you have the strength that the center divider board offers. In a single chamber setup, the baffle can be prone to flex in the center, especially if you mount the woofers close together, which is exactly what you want to do if you want to take full advantage of the coupling benefits that a single chamber box offers. The woofers in theory will work together to form a sum bigger than their actual sizes. This translates to a bit more output in most cases. What I do if I decide to make a single chamber sealed box is to go ahead and make a center divider and cut it out leaving about an inch of wood all the way around. This way you get the benefits of woofer coupling while retaining a super stiff baffle. Place the two woofers as close together as possible. With either design I always put a thin layer of dacron filler on all sides.... it gives it a warmer, more round tone and eliminates that bouncy, pingy sound of bare wood. MDF is a very hard surface and it's reflections are less than ideal. You can also make the box slightly smaller this way if you are tight on space.