OK, so in the quest to explore hooking up multiple cabs with the BH500, like a 3rd speaker on the other side of the stage, or behind the drummer, i explored feeding an external amp through the front panel XLR output. First, i tried an old school Carver PM 300 that i use for close field monitoring and mixing ( I LOVE this amp for its accurate sound, not for loudness.) Connected head to the amp XLR toXLR to a JBL JRX115 PA cabinet. Output was abysmal with amp in bridged mode (300W). Not nearly loud at all even with the external amp pegged on 11.... So then i tried a QSC RMX850 that i borrowed from my home theatre (I run 3 of these plus a HSU powered sub in a 6.1 configuration), and same thing. I figured out that the XLR output is controlled by the PREamp gain, not the master. Disadvantage is that you cannot turn the pregain up ENOUGH to drive the input stage of a normal commercial power amp sufficiently without your peak level on the preamp going crazy. I have a dbx 163x that i plug into before going into the BH500 preamp. I just have had this compressor for so many years that no other compressor has that FAT analogue sweetness. NOT that the SPECTRACOMP is BAD at all. But i have the output gain on the DBX at unity gain and still I cant turn the pregain on the BH500 past 5 without it peaking. So if anyone had any sucess with this I'd love to know. Only solution I CAN THINK OF is a single rackspace mini mixer to run the head xlr out into and then feed the external amp through the mixer. But then im going from a 2 rackspace to 4 plus the amp rack. Unless I'm missing something more obvious?