For you all setting the xo at 40-50, what surround speakers are you using?

Your AVR enable for you guys to set individual xo for each channel?

My Marantz can only set a universal crossover and my surround can only go to a min of 80Hz, would I damage the surround speaker if I set the xo at 50Hz? (I have a SVS PC12+ which can go below 25 Hz easily)

I set my L/R at large now as I wanted the M60 to go lower than my current xo at 100Hz and center (VP150) at small.