Ok, I've been playing a lot with WinISD lately with midranges and bass drivers, and think I can draw some conclusions on how stuff works. It'd be nice if people could check me on this and help me out. Qes = the higher the better for sealed boxes (what I'm interested in), I noticed that higher than 1.0 gives a bump that can't be rid of (Morel MW266). Why is this? fs/Qes -> EBP = lower better for sub driving. Am I correct in assuming it affects how drivers roll off as well? Qms = Don't know how this affects things. Higher/lower explanation? Qts = the lower the better for smaller box size? Vas = lower is better for smaller boxes? Larger drivers have larger Vas. I could use some help here too. Le = the lower the better for high frequency extension right? What else does this affect? For power handling, say I input a Tumult in a 4 cu. ft. box (Q=.577). WinISD says it can handle full power (1600W) down to 21Hz or so. Is this possible? Is the voice coil or the box limiting it there, or is the excursion not enough to push the mechanical limits at those power levels? Thanks in advance. P.S. Yes I have read Loudspeaker Design Cookbook, the older 4th edition, but still a good reference to me.