Changing receivers changed my sub phase - normal?

[lovingdvd]

I used REW and BFD a month ago to set up my Yamaha RX-V1400 and HSU sub woofer just beautifully.

I just got the Yamaha HTR-6090 which is very much like the 1400 except its more modern (the 1400 is a couple years old), has better processing and HDMI switching.

I used Straight for the 1400 and now on my 6090 too. However something just didn't sound right with the sub after changing receivers, so it was time to break out REW for some action!

What I found was that there were a couple nasty dips around 60hz. Even just listening to frequency sweeps the bass just didn't seem even.

So I switched the sub woofer to be OUT OF PHASE and rats if that didn't solve my problem. The dips were gone and frequency sweeps sounded nice and even again.

I know for a fact that with the Yamaha 1400 the correct position was IN PHASE. So I was a bit surprised to see (hear, actually ) that the correct setting with this new config was to have the phase set to OUT.

Does it make sense that changing receivers could do this? I thought the phase was more of a function of the speakers themselves and the room size.

[JohnM]

Some receivers (and some amplifiers) are inverting. Also worth checking that you didn't swap the speaker connections around and invert the response that way.

[lovingdvd]

JohnM wrote:

Some receivers (and some amplifiers) are inverting. Also worth checking that you didn't swap the speaker connections around and invert the response that way.

Thanks, cabling is correct. I just find it interesting that a newer model of basically the same receiver (albeit improved) would have this significant difference (phase change).

Interestingly they also added an option in the receiver setup options to invert the subwoofer phase - so they must have been aware that their change would cause this in some systems.

I feel bad for all those out there with sub setups that have no idea of what sub eq is about, with wrong phase connections, and don't even know what they are missing. I was one of those folks up until a month ago. Wow what a difference. Keep up the great work.