Why wouldn't you just connect the sub to the preamp outs and not worry about possibly shorting the amps outputs?
Using a REL Storm with a Spectrum Amp?
I have a Spectron Musician 3SE Mk2 amp and I have been using full range speakers. I am demoing a set of monitors and an REL Storm III sub. Does anyone out there see any problem with running the sub by using a Neutrik NL4FC cable from the sub to the terminals on the Spectron...where the the positive and negative leads would be connected to one side of the amp speaker terminals and a single wire connected to the negative terminal on the other side? Just want to make sure all components are protected!