Can hardware change speaker phasing over time??

:-)   Is that movie really worth watching???  I'm on the edge.

The trick here is that the wires really didn't get switched.  They were the same as always, but just started sounding out of phase.  Once I switched one speaker, that solved the case for sound.  But the speakers are now, technically, wired out of phase.

Hence my query of whether the phase signal could have been changed somewhere in the Denon or the Parasound amp?

mozartfan, I think you posted in the wrong thread, but try hooking your speakers up out of phase to see if you get any interesting results!

I also just tested this with a Stereophile Test CD (which bypasses the DAC), and the speakers definitely meet the test for being "in phase" though they are wired out of phase. (Disk 1 "The fender bass was recorded equally in each channel...")

My point is that everything was fine for years, and then suddenly I wasn’t hearing what I was used to. There is no evidence anybody changed anything in the system. It’s been this way a really long time.

I also just re-ran the Denon Audyssey room check, and now it’s telling me the Front Left is out of phase. And yet, the imaging is back to normal as if the speakers are actually in perfect phase.

@rixthetrick Very good ideas!   I tried this tonight.  I love that right now my living room floor is covered in wires and loose CDs, just like the old days, all in search of Truth!  (If only there were full ashtrays, empty wine bottles, and some young woman's unmentionables scattered in there, too.  Everything that made me love 2 channel!)

So I got an old dusty Playstation One out of the basement (Stereophile Magazine's #1 all time CD player) and plugged the right and left channels directly into my Parasound Amp.  So now we have bypassed the DAC and the Denon completely.  After adjusting the levels on the back of the Parasound, I played multiple Stereophile test disks phase check tracks (both Fender bass guitar and even dogs!), and they all sounded better and proper with the "out of phase" wiring instead of "in phase."  At this point, you are all rolling your eyes and saying one of his wires is crossed, but I have checked that many times.  I also played other CDs, including Rebecca Pidgeon, that normally produce great imaging, and they are all better after I rewired that one speaker.   It's interesting that the Denon, when included in the stream, still believes I have that one speaker out of phase, which I do if you just look at the speaker wires.

Anyway, I'm just going to put it all back to normal with the one speaker "out of phase", and keep grooving on some Nick Lowe and Cowboy Junkies.  So strange because the regular wiring worked for me for years, but suddenly we have this alternate sound that cannot be explained, but it can be fixed!

Tonight I'm going to drag up a different pair of speakers and see what happens.

The mystery deepens! At lunch I hauled up my father’s old Mirage speakers and hooked them up to the full system, wired "in phase", and they sounded and tested as "in phase." So it has to be the B&W speakers.  I put the B&Ws back in the system, and they still only sound "in phase" if wired "out of phase."

Tonight I will hook them up to a different amp and see what happens.

And I have now created a special curse for B&W because you cannot use banana clips on them.

Listening to the CM10s wired "out of phase" was pleasant and produced good imaging with vocals and the Stereophile test tracks for phase.  But then I noticed I had lost a lot of bass on some songs.  Loss of bass is a side effect of being out of phase.  Wiring the speakers back in phase brought back the bass but lost the great vocal imaging.

So the only logical conclusion is that it's the tweeter or midrange driver on the one speaker that is out of phase from its counterpart.  I plan to test this hypothesis tonight with a bunch of test tones and see which ones sound focused and which ones sound diffused.

Here we are, six months later, and last night I noticed I could hear and "see" each speaker again.  The vocals were not centered.

I wired the speakers back to "in phase" and the world was right again.  I have a wandering phase issue, either with one of the speakers or the electronics in the receiver or amp.

I understand the A/C capacitor issue.  When my capacitor went out, I could hear the unit trying to start, so I put a stick through the grill and gave the fan a push.  Sure enough it started running, though I had pushed it the wrong way!  The air was blowing down over the condenser, which still sorta worked.  Then the A/C guy came out and charged me $230 to replace the $12 capacitor.

As for training my ears, I had a lot of friends, at least one who is an audiophile with 5x more $$$ invested in this hobby than I have, and he heard the exact same thing.  Anyway, everything is back to normal.

Of course, as a hobbyist, I am now thinking of buying a new Lexicon receiver to replace the Denon.  It's just that damned urge to upgrade again.