I have been trying to come up with a cabinet plan for a few months, and have learned a lot from the posts here (thanx to Bgavin, Joris, Geshel, and others). My wife has convinced me not to build a box for resale value, so I will be redesigning one and I'd like some input from anyone with an opinion. My design goals are primarily ease of carry, and second low end response. I'll be making 8 ohm boxen, and can push about 250w into several of them and will biamp (Yamaha PB-1 / QSC RMX-1450). I play mostly classic rock and blues or country with a neck-thru 5 string. I will buy an Avatar B112 (Eminence Kappa 12 and a tweeter) in a 2' box; (2) 4"d x1"l rear ports tune it at 92hz as I calculate. This box will be driven either full range or biamped for the highs (so I don't kill it). I will probably block one of the ports and replace the other with one 5.5" long to retune at 45hz (Fs for the driver) although that's optional if I biamp; might be nice for very quiet gigs with lots of EQ. I will then buy a B112 empty cabinet and fill it with a Kappa Pro 12; block up the tweeter hole and one of the port holes, and fill the other port hole with a 4"d x 11" l tube, tuning the 2' box at 35hz for the fundamental of my 5 string. I will make as many of these boxes as I require to make volume, and could biamp and still push 2-4 of them off one channel of the QSC. I chose the Kappa Pro 12 because it has the best Fs of the bunch, and it's $100. The Delta 12LF was close, but has a smaller magnet and higher Qts. The Omega Pro is nice enough but I couldn't see a reason to spend $150 when $100 would do (until you tell me otherwise). I believe that a single 4" port should be adequate, but perhaps I'd be interested in other opinions on that as well.