The "Acoustic Friendly" option: Reduced-level rear-firing tweeter that adds a bit of top-end energy to the reverberant field and therefore comes a little bit closer to mimicking an actual acoustic instrument, and also lets anyone behind the cab (drummer perhaps) hear the overtones a bit better. More useful for upright bass than for electric bass. Adds about 1.5 pounds to the cab and $100 to the price.
Thunderchild 212v2: 4 ohms: dimensions 34.5" tall x 14.5" wide x 14.5" deep; 47 pounds; 97 dB; 900 watts; -1 dB at 62 Hz with normal tuning; pluggable ports give two ported and one sealed option; top end switchable between 3.5 kHz and 18 kHz (-3 dB points). Another switch toggles between smooth mids and a bit of grind in the mids. Woofers are stock Kappalite 3012LF. Price: $1200 + shipping.