As cabinet volume decreases the low bass will decrease but should tighten up, and if the volume goes too low a peak (sounding boxy) will appear. Is that right? Styrofoam is closed cell. Suggest a different lightweight material? * Ok, I'll tell the whole story: I'm using a low powered tube amp and that won't change for now. I understand that the low damping factor loosens the low bass, and combined with a ported cabinet I couldn't stand it, so I blocked the ports and I think it sounds better. But I've read that - provided the driver is suitable for both sealed and ported cabinets - a sealed cabinet should be smaller than a ported one for that driver, and the Eminence suggested cab sizes seem to confirm that. I don't know the exact model of the speaker, but at least one person on this forum said it's closest to the Delta 15lfa: "This comes from my direct asking to Eminence". If that's the case, then it takes a 3-5.9ft3 ported (my box is 3.25ft3), or 1.3-1.5ft3 sealed, according to Eminence. Just wondering the audible consequences of using a sealed box 2x bigger than Eminence recommends.