Oh heck, the description (from your profile) is worth sharing too:
"
Sansamp 1.1 preamp used in the send/return of a Carvin BX-1200 bass amp, this amps output is bridged in mono and drives an 'upright' 1970 Sound City 4x12 PA cab. the cab's been retrofitted with (4) Eminence 16 ohm 'Swamp Thang' speakers (this cab is used for high power 'mid bass & mids') For lows I take a DI feed from the Carvin and feed it into a Parametric eq which then feeds a Crest FA-1201 power amp thats bridged in mono, this powers a double 18" cab which has been retrofitted with (2) Eminence Definimax 18's. The mid cab is rated up to 600 watts in the 100-5khz range. The low cab can handle up to 1600 watts in the 30-125 hz range"