Hi all I need some help if anyone can..... I originally had a Yamaha 371 Av receiver and Tannoy sfx 5.1 set up. About two years ago the unit over heated and since that day I had issues. Bass went completely to effectively nothing. Prior was fantastic. I started getting a lot of distortion and in the end had to just put up with the crossover being set pretty low on both the sub and the receiver. I used the YPAO mic to see if the receiver had reset and whereas before I had clear rich bass coming through half of setup had no noise what so ever and the bass sounded like a can of coke being opened. I ended up selling the tannoy sub and the person who bought it said was it was working fantastically and has since had no issues so that made me assume the issue could of been the receiver but I opted to try a new sub 1st as I obviously needed one. I ended up buying a new sub and centre speaker. I got the wharfdale sw150 and diamond 10.cc. Still the same issue. But of course I assumed it was the receiver causing the problem and was going to replace that at a later date, I had the cross over on the sub set to 85 and on the receiver to 80. I ended up with the sub at 55 and the receiver set to 60 to lower the distortion. I was constantly having to manually change the sub level depending on what I was watching. For music I'd have to set it to full to get any bass whatsoever. On films on scenes I know there was bass before I'd get nothing then fantastic bass for someone closing a door for example. I tried setting it up with the YPAO mic and same issue, pathetic bass, basically a little crackle and then the remaining set up silence on the subs turn also this time phase warnings which I could never get rid of. But like I said before assumed the unit had gone and was going to replace it in due course. I took a year out of bothering with it all (due to a death within my family) I've now decided to get back into sorting it out. I replaced the Receiver this weekend with a Yamaha 475. I still have the same issue! Tried the YPAO and its the same as on the other receiver the bass sounds horrific, tinny and it only gives out one minute burst at the beginning of the setup then during the subs turn nothing at all. Exactly like with the Tannoy on the 371 and then the sw150 on the 371. So my problem is, I don't know if the original 371 and the sw150 are both screwed or the new unit's just the same, or the sub is gone (which I replaced to sort the original problem out) Its really beginning to annoy me now. I cant of been that unlucky that the sub I got was also gone as well as the original unit. I know for a fact on the YPAO setup there should be bass other than one fizzy, tinny growl at the beginning. I remember the set up well when I originally did this with my last set up, it was like the heartbeat of a giant. There's literally 40% of the setup now with nothing even though the indicators showing the sub as the output on them parts. Originally when I used this set up I'd go and have a cup of tea and wait for the last growl and that would be when I knew it was done. Now nothing (same on the other unit after it over heated) The only thing I can assume is when I replaced the sub and put it onto the 371 this has damaged the sub from when the original receiver was broken. Can someone help me with this please as I'm out of ideas. I can't keep replacing subs and receivers willy-nilly and getting the same results. There has got to be something wrong here. The fact the setup puts nothing out is now baffling. Its like the sub isn't getting them frequencies or isn't bothering to put them out that's for sure.