I have been enjoying a SVS PC12 Ultra through the avp700 rca connection. My second sub arrived today an Axiom EP600 which has XLR inputs as well as the usual unbalanced connection. While splitting with an RCA adapter and running unbalance to both subs is an option, Axiom recommends the balanced connection. When I run an XLR cable to the sub, the voltage is such that volume is very sensitive to small changes in gain control on the EP600. Fine tuning when calibrating is more difficult. I am told there is a pro XLR setting and a "consumer" XLR setting. Does the engineering menu have an adjustment that controls voltage in the analog outputs, specifically the XLR outputs ?