Center image WAS driving me crazy!

During last week an issue is driving me crazy and this forum might help me as usual.

Let’s talk about center imaging.

I have perfect centered voices, very palpable and real, listening to almost all my CDs and records. Streaming from Qobuz included. Same for acoustic guitars.

Sometimes something happens very annoying, it seems that higher frequencies from electric guitars are more audible on the left and the left (and only) speaker suddenly re-appears. It causes an unpleasant loss to the symmetry of the soundstage.
One day is terrible and another day is all ok without changing anything in room or gears. I double checked set up of the speakers, connection of cables, clean wave and THD on P20.

I tried moving speakers closer to each other and back, forward from front and side walls and back. Toed in, tilt and back. Back and forth the listening position and… nothing changed. I tried repositioning some bass trap and diffusers, even putting them out of the room and… nothing. One day is ok and the day after the problem is back again. No reason, apparently.

The right channel still remains perfect, the right speaker always disappears as usual.

I read the Audiophile Guide book, 3 times almost, tweaking with set up without success. Never had this problem before.

Am I totally crazy (or I’m simply going older) and this is due to my “mood”, like a psycho consequence? Playing the same albums I can get different results in different evenings.

Any idea?

Please don’t tell my wife I’m in trouble with these things!

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This issue may very well be record(ing)-specific.

It seems to me that sometimes the mix is very channel specific and the “spatial cues” are smack dab in the middle of the channel, so to speak.

Have you noticed this phenomenon to be limited to a few recordings?

Just a thought…

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Hi Luca,
For a test try to sit facing away from the speakers or swap the speaker cables from left to right and see if the degraded sound moves to the other side or other ear.
It could also be a faulty wire connection somewhere in the left signal path. Maybe a problem inside the speaker cabinet?
Maybe a problem inside the preamp or power amp?
It could also be a defective or worn out vacuum tube in the left channel causing the issue.
Good luck finding out the cause!
Vern

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Yes sir! John Mellencamp’ albums (Freedom’s Road or Cuttin’ Heads for instance) are the worst, from Qobuz. But the odd thing is that they sound different in different evenings. Not my favorite albums at all, just the ones that are more annoying on the left pronounced effect in my room.

If you have the opportunity to play them for a while I’m so curious to know if in your system the image (as for the electric guitar on the left) is correct or not.

Thank you for your help.

I’ll try to do that when I get a chance.

Inspired by an @Baldy comment, I would suggest unplugging and re-seating your speaker connections at both ends.

Very interesting…

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Mmm I cannot never have relax in this hobby!

Thank you Baldy, I’ll give tubes (in BHK Pre) a try first, you are right this is a good point to start. As for cables swapping as second. Tubes in M1200s are so recent I tend to exclude them.
As for speaker possible faulty problem, naaa think positive (fingers crossing).

It’s not a question of noise or distortion, the left speaker sounds good apparently and the soundstage is centered for instruments in general on low and high frequencies and is perfect for voices. It tends just to reveal the speaker (it re-appears, I hear the sound coming from it and not behind it) only and exclusively when an electric guitar is playing higher notes, the lower ones from the same guitars are ok and come from behind.

I’ll do again this evening as accurately as I can, checking both ampli and speaker spades on both of them.
I have also checked my 2 subs and switching one of them off seemed to reduce the problem for a while, it made me think I found the culprit but after a few songs the bad electric guitar has made my left speaker re-appear again.

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My guess is that if it has to do with anything in your system, it will happen with any recording.

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Just a thought - I have long maintained that the sound of my system varies according to ambient temp and (especially) humidity.
Speakers made from wood / paper / textile seem the likely culprits.
I don’t know what the weather is like where you are but here we get regular variations between 40% and 80% max, which is quite a range, and bound to make water-absorbing products change in size and flexibility.
I may be imagining it, of course :slight_smile:

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Luca, if you want to brute force things, swap the speaker cables and the speakers - left to the right side, right to the left side. Although I agree to check the tubes first. I’ll try to listen to those recordings later today.

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I agree with tony22, you need to swap the speakers. It could be a tweeter that’s been overdriven and has a coil that’s intact but occasionally buzzes as it warms up.

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Thank you. Can’t imagine how I’m hoping you are wrong!

This evening I’ll investigate more.

I tend to agree with this. Not just any recording, but why only the guitar? Wiring issues would not cause just that instrument to do that.

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You mention base traps and diffusers, but do you have absorption at the 1st reflection points?

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Both of them Elk, take a look at this:

they have a magnetic technology applied able to put diffusers on the face, like these:

I also tried without bass traps at all without success. My doubt is: why sometimes I have the problem and sometimes not, it seems not to be dependent from set up of the speakers or acoustic treatment.

A frustrating problem.

If the reflection points are well treated it does appear to be unrelated to acoustic treatment.

I do not understand how it can be intermittent.

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My first thought was tubes in the Pre. Swap them around, it’s an easy test.

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Hi Luca. I’m listening to Cuttin’ Heads now. There’s a lot of “on purpose” left guitar / right electric or stuff like that on these tracks. If you have one or two tracks in particular with specific times where you hear these oddities, it might help.

Thanks for your help. Let’s go testing…

Swapping left/right speakers I can now confirm (phew) the problem is still on the left speaker. I can exclude some faulty thing related to speakers.

Good news! (I think)

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