Need specs on old school Orion xtr1400 amp, and a oxygen audio air 2pro N2.5kw amp both work fine but I need to know which is more efficient with my 06 cvx 12s d4 wired to 1 ohm( dunno if the Orion is even 1 ohm stable.)

Please help . Also have the older mofo 15s that have a 4" basv/ kapton v.c. if they wud get lower than the cvxs....thanks a bunch guys!!!

I have the CVXs in a 3.5 cu ft itch box tuned to 33 hz with a 4.5" l port