Hi everybody looking for some help I have a yamaha 750 amp running 5 bose cube speakers and a rel quake subwoofer. when i attach the rel quake hfe input using the speakon cable and turn the amp up to around -22Db the amp shuts itself off. when you turn it back on it comes up with check sp wires. I have checked all terminals to make sure cables aren't touching. To resolvce i have tried putting the hfe cables into set "b" of speakers on the amp, tried attaching the hfe cables to other speaker cables like the rears and it still does it. If i only have the RCA for the lfe signal then it works fine but there is some midrange missing between the rel and the bose so not overly great. I have the cross over at 160HZ. all the speakers are set to large and ohms is set to the 6 switch on the back. why is it that when i connect the hfe cables there is a restriction in the volume i can play my music and how can i over come this? any help would be much appreciated. Thanks. Paul

All of the cubes should be set to small then connect the sub by RCA. Bose cubes are tiny and that is where your midrange is going - more of it should be directed to your sub which is why you need to assign your cubes as 'small'. Also, make sure that your sub isn't controlling the crossover point - you should set it as high as possible and the amp will decide the crossover point.

To run a sub from the speaker points of your home cinema amp, you would need to connect it to all five channels and the amp isn't really built for that & I think your problems are coming from there.

With stereo amps, connecting the sub to the speaker sockets is probably the best way but with multi channel, it's difficult and messy - don't do it.