I have been running my subs (ev qrx 218) on a Rmx 5050 for about 2 years, one sub per channel. Recently I acquired a 22year old ex 4000 to run my "B" rig same subs. Now I kind of like to extract every last bit of output from my amps (about 1/3 power as described by qsc) and to be honest, the ex...