Greetings from Texas! I have lurked here for a couple years, trying to absorb everything I could from the vast knowledge bass (pun intended)...BTW, (many props to BFM, GB, JohnK10, etc, etc) and have now gotten to the point where I have a few solid concepts, but need some clarification on a few things that I have not been able to find in the other threads. Although I have played alot of rigs over the better part of 35 years, I never really paid any attention to the science(s) behind speaker cab designing. I am about to embark on my 2nd custom DIY cabinet (the 1st one looks awesome, but sounds like crap), which will be very similar to JohnK10's Starliner. I have tried WinISD, but I find that BassBox 6 Pro works better (for me, that is), so all figures come from that. Here's the plan... The concept parameters: A lightweight 2x15 loud enough to stand on it's own on most gigs with little to no PA help. Driver choices: Eminence Legend cb158, BassLite2515, 3015 (non-LF) The box: Total internal volume is 7.279 cu. ft., tuned to roughly 45hz, depending on the driver. One thing I'm confused about...I've seen the term 'displacement limited to XXX watts'...am I correct in assuming that that is the max power your cab can handle at low frequency where the driver(s) reach Xmax and any power applied over that will only bring doom and despair? For instance, If I use the 3015's, cab tuned to 44.27hz with (2)-4"x0.75" tubes, with no fill, BassBox shows maximum cone displacement of 6mm between 80-90hz with 800 watts. Is that the displacement limit figure? Would it be correct to assume that this box would run fine with just about any head up to the 750-800 watt range, so long as I pulled the low-bass back a tad? I have several head possibilities in mind, but, more on that later..gotta get the cab ironed out first. Any thoughts, ideas, opinions, etc. will be greatly appreciated. Thanks.