Xr 8600d peavey pa when I turn it on it turns off

SOURCE: how do i connect the cables between peavey vocal

if you mean effects loop try graphic out to ultraverb input and output to power amp in. this will effect all channels of the xr500c

SOURCE: can i connect the pv 112 to the pv 118 subwoofer

Generally speaking you should only send low frequencies to subs. The highs, while lower in power than the lows, will over time harm the voice coils. The ideal way to do this is to use an external crossover netween the main output and the amp input with the higher range going to a general set of speakers. Send the lows through the second channel of the amp and then to the subs.

In short, while not recommended, yes you can hook them up in parallel.

Dan

SOURCE: Useing a Peavey XR 800F

First of all confirm if the speaker impedance is not lower then the recommended Ohms at the back of the Mixer speaker socket.You can use an 8 Ohms speaker on a 4 Ohms amplifier but not vise versa .
Next see if the fan on the mixer works. If not the Amp is getting very hot and this will lead to unwanted distortion. You can confirm if its a heat related issue by playing the mixer at low volumes for more than an hour and see if it distorts.