I'm sorry to both revive a thread and to hijack, wasn't sure if I should create a new thread or not, but I just hooked up a Yamaha RX-V577, and am having major issues with the subwoofer level output. I have a Pioneer SW-8MK2, but I can barely hear the thing. I've used the YPAO setup exactly as it described, and the sub was practically inaudible, I had to turn the sub over and feel the woofer just to see if it was even making any sound while cranking the receiver to a far louder level then I normally would listen at. I turned on the sub, enabled extended bass and all that like the manual recommends. I even manually went and messed with the gain levels, for it to be even a remotely audible level I have to adjust the mains to -10db and the subwoofer to +10db, but the bass level is still rather low (better, but a lot lower then I'd like while listening to music).
I've had the exact same 5.1 setup, same wires and everything hooked up and tested with two different receivers with absolutely no issue with the low pre-amp sound from either other those, one of which was even an older Yamaha, and the other was a newer Sony 5.1 receiver. In fact, on the subwoofer adjustments I had the gain down to almost a quarter and had plenty of bass, with the new receiver I have it cranked as high as it goes just to even output sound.
At this point I'm debating on returning the receiver, but I really like it other than the subwoofer issue and got a great price on it. I've ordered a pre-amp and will try that in a few days (unless there's absolutely a specific reason I shouldn't; I will turn down the gain and slowly inch up so I don't blow anything). Did anyone find a solution for the Yamaha low line-level outputs? Its gotta be the receiver, because 2 other receivers work just fine (and it's not broken, since it does output to the subwoofer, just a really, really, really low level).