Powered subwoofers running into power amp?

El redundo amundo. "Loading" of the low impedance balanced signal from a pro audio mixer to the balanced inputs of pro amps in the real world is nearly non-existant, and nobody who mixes shows (like me, for decades) worries about this even when using 100 foot cable snakes driving multiple amps.

Wolfman

The OP didn't say he was a pro using balanced line 600 ohm outputs, amigo.

If he was, I doubt if he would have asked this question.

It's hard to imagine he found a mixer that doesn't have balanced (either XLR or tip/ring/sleeve) outs...but I will conceed it's possible, amigo. That said, if he's that unsophisticated I doubt he understands any convoluted explanation regarding capacitance.