Hopefully someone here can help me out with this one.... My setup was Polk LSi's and SVS subwoofer hooked up to my Yamaha HTR-5760. Everything were working just fine. I recently purchased a power amplifier (Rotel RMB-1075), so all the Polk LSi's are now hooked up to this amplifier, and amplifier is hooked up to the preouts of the Yamaha receiver. The subwoofer remains as is on the Yamaha receiver. I did not change any menu settings on the Yamaha receiver. The problem is that I do not get any sounds out of my subwoofer. So I then got my old receiver and hooked up only the sub to it to see if the sub is working. Sure enough, the sub works! So I think it might be my Yamaha receiver. I even tried resetting the receiver back to factory settings... still no sounds from the sub. All speakers are set to small, LFE is set to subwoofer, crossover is at 80. Anyone have any ideas what is going on? Am I supposed to set my receiver up a different way when using it as a preamp? ..... I just thought of something... does the 6 ohm/8 ohm settings on the back of the Yamaha receiver have any effect when I only use the preouts? It is on the 6 ohm setting. Maybe I'll switch it to the 8 ohm setting when I get home since the speakers are now hooked up to the power amplifier. Any help is greatly appreciated.