I have built a few boxen and was acoustically satisfied with most of the results. I have blown drivers out of commercial 2x10 boxen using a bolt-on 4 string (hyperexcursion I imagine). I have been playing a neck-thru 5 string and am getting pretty spoiled with the extra range. I am considering making some 2x10 boxes based on Eminence BP-102's. I realize that these won't be flat down to 31hz, but I have to sacrifice somewhere because I want small/light boxes for gigs, and I figure I can do 1/2" Baltic Birch on these and they will survive physically. Is there a way to assure I won't smoke these drivers with a 5 string? Tuning the cabinet to 30hz? Blowing off low end and going sealed? Or am I just destined to trash these with occasional use of a low B? My runner up choices are Dayton 15 (4"vc fs=37) and Eminence Magnum 15LF's but I would have to move up to 3/4" Baltic Birch and a lot more weight.