Imaging Issue – Center Image Pulled to the Left

[gianluca_v]

Yes, issue happens on several different tracks I've been using since years as reference.
Anyway I asked my dealer to take the amp to their shop and test with any source, cables or speaker they have available at their place. By doing so Im sure I will be able to nail down the issue. Keep you posted

 

[evalrat]

I followed the discussion for a while to see how it would develop. I did have similar problems with my Quad Esl's.
It first occurred when we moved to a new house. There the living room had a U shape due to a closed stairwell.

Originally the loudspeakers were positioned along the long wall. This resulted in a serious unbalance between the speakers.The unbalance was about 6 dB requiring the balance slider moved from the middle to almost one side. Swapping the speakers made no difference. Situation remained the same. The problem was in the room. I found the solution in placing the speakers on the opposite side of the between the stairwell and the window. Proved that the stories about Helmholz resonators are true.

When we moved to our next home the speakers ended up in my hobby room.

Sorry that it looks like one. Here the speakers are positioned between a hard aluminium faced cupboard on the left and book shells behind and at right side. The speakers are about 1.5 meters from the rear wall. There it seemed that the treble panel of the left speaker was faulty. At that moment the orange boxes between the left speaker and the audio weren't there yet. The equalizer is there to lower the LF resonance peak of the bass panels. That peak becomes higher when the panels age due to stiffening of the membranes,but it offered no solution for the HF problem. Swapping the speakers again made no difference. The 1m frequency response didn't look strange either. The solution came by accident. I needed some room and placed the little chair with the orange boxes between the left speaker and the audio stack to get them out of the way and if by magic the speakers switched to a correct tonal balance. So now the stack of little boxes remains there. What baffles me is that the solution wasn't in creating symmetry between the left and right sides of the room but in filling a gap between the audio stack and the speaker in the hard/soft corner. Again the problem was some parasitic resonator. I hope this story encourages gianluca_v to look at the room and positioning rather then looking for an audio processing solution.

 

[digitalfrost]

I have a similar problem. On the left side is a wall, on the right side there is ~1m space then the roof comes down (angled roof). Left is red and right is green. You can see in the bass the influence of the wall. I will attach measurements if somebody wants to analyze.

If I run correction with drc-fir, I notice an image shift to the left when I apply the convolution. At the moment, I have after convolution turned the left channel down by 1.3dB. But that is just for being on par with what was before. Really to have it in the middle, I'd rather use 1.7dB diff.

 

[SteveC]

I went last week to an audiologist as I was start thinking that if I could not find any fault with my system maybe I was the fault Both ears are perfectly clean and the audimetric test did not reveal any asymmetry between the two ears.

That's awesome! One less thing to worry about!!

 

[Arindal]

Originally the loudspeakers were positioned along the long wall. This resulted in a serious unbalance between the speakers.The unbalance was about 6 dB requiring the balance slider moved from the middle to almost one side.

As your Quad ESLs are apparently dipole panels, this might result from a significant imbalance between the reflections caused by the rear level maximum of both the left and the right panel. Your first sketch is showing the left panel´s rear side is pointing towards the wall behind the speakers in a way the reflections would go to the middle of the room with no way of hitting the listener, while the right channel´s rear soundwaves will almost like a pingpong arrangement with 2 reflections (rear wall + side wall) hit the listener´s ears with almost full level.

Dipoles in an asymmetric arrangement regarding the rear wall reflections, are always a very bad idea.

 

[evalrat]

As your Quad ESLs are apparently dipole panels, this might result from a significant imbalance between the reflections caused by the rear level maximum of both the left and the right panel. Your first sketch is showing the left panel´s rear side is pointing towards the wall behind the speakers in a way the reflections would go to the middle of the room with no way of hitting the listener, while the right channel´s rear soundwaves will almost like a pingpong arrangement with 2 reflections (rear wall + side wall) hit the listener´s ears with almost full level.

Dipoles in an asymmetric arrangement regarding the rear wall reflections, are always a very bad idea.

Yes, sound reasoning. I expected no troubles as the speaker were positioned well over 1 meter from any boundary. They were positioned in that way because the room had been arranged that way before with box loudspeakers. The speakers had been in storage for over 15 years and had just returned from a restorer (Arend-Jan Wijtzes). He rebuild in them in 2011 for a very tempting fee of just 1200 euro for the pair, and quite good taking into consideration that they still play well today. I reasoned that that what were the finest speakers on the world when I bought them in 1975 would still sound good in 2011, so I in stead of buying new speakers I took the bet. After I mirrored the location on the basis of the "common" wisdom that the direction of the sound should go from narrow to wide the problem was solved. And now they play nicely in my hobby room that of course is much smaller then the space they had been designed for.
BTW. This is no advertisement for these speakers, that of course are historical equipment, dethroned long ago when the B&W DM6 and KEF 104 came to the stage.

 

[Arindal]

They were positioned in that way because the room had been arranged that way before with box loudspeakers.

That sounds reasonable, but you have to take into account that planar dipoles have a completely different radiation pattern compared to front-radiating box designs. While with the latter the side wall reflections of frequency bands subject to broad radiation are dominant (and need to be looked at), bigger planar dipoles usually usually produce a good fraction of their sound pressure within two ´beam windows´, one to the front and a similarly strong one to the rear. How reflections of the latter are handled, is key.

 

[Ktacos]

I have this issue, but for me everything pulls to the right. I've spent a lot of time trying to figure it out but haven't reached any real conclusion but speculate it is related to my own hearing. Ultimately I found that adding 2db to the left fixes things to an acceptable level.

I have measured the output of my amplifier and used different amps, no change. Swapped speakers, measured their FR and impedance. I've got a good amount of thick treatment up and have setup my speakers with a laser so I know they're the same distance from me. I also experience this problem on other setups.

I ended up going to the ENT several times, plenty of hearing tests but I don't think they pick up what I feel the issue is. I pass hearing tests with flying colors and have even had CT scans of my, but what I've found is that my ears hear the same pitch differently and I think it's because my ear canal shapes are quite a bit different.

Over time for whatever reason my jaw has shifted up on the left side of my head, the upper part of my jaw at the joint (sorry not a doctor) is about 1/2" higher than the right. I believe this has changed my ear canal shape which causes a change in how sound traverses through my ears. I don't feel any test I've received has accounted for this, they mostly just test sensitivity and FR, but not things like pitch perception.

I've tested this issue in a few ways, mostly down to isolating signals from left and right speakers/headphones and playing them back in each ear. Works better with headphones but to me, it's very clear that my ears are not hearing the same pitch even when given the exact same signal.

As I mentioned increasing the left channel by a few db seems to make me happy enough.

 

[Matt_Holland]

This might be a long shot, but... could you have some wax buildup starting in your right ear?

Came here to say this. I recommend micro suction as opposed to syringing. Less prone to infection.

 

[Keith_W]

Came here to say this. I recommend micro suction as opposed to syringing. Less prone to infection.

ENT's no longer recommend syringing. There is a risk of eardrum perforation with syringing. I was not aware of this and was about to comply with my patient's request for syringing when my nurse stopped me. Thank God for nurses.

 

[Matt_Holland]

ENT's no longer recommend syringing. There is a risk of eardrum perforation with syringing. I was not aware of this and was about to comply with my patient's request for syringing when my nurse stopped me. Thank God for nurses.

Wow!
In the UK you can still get syringing. I’ve had it three times in my life all within the last 14 years and I’m not comfortable having it again knowing the risks now.

 

[Madlop26]

My main system also tends to shift to the left, but my near field system is quite death center, so It has to be some psychoacoustic of reflections, there is a drywall with sound treatment on the left and big long Curtains on the right.

 

[onununo]

My room and system setups are the same as those of Gianluca (see attached picture - what's on the left of the left speaker is not a wall but just a column, the room is otherwise open on that side) and I have the same issue, except in my case the image shift is towards the right (2.8 dB of unbalance to be precise). I am 100% sure it's not due to the speakers because I get the same result even if I swap them. In addition, they are active speakers, so amp issues are also ruled out from the equation. Also the DAC and the cables are ruled out, because I have tried swapping the channels at the speakers' input (the cable connectors) and the problem persists. Finally, even the track I am listening cannot be blamed, because I select the MONO mode in my DAC to make sure I am not tricked by the stereo recording (and also because even when in stereo mode, the effect is more or less evident depending by the tracks, but it is clearly there). So nothing remains in the equation except maybe my ears, but If I use phones, or listen to a point source in front of me, or best of all, listen to the second stereo set I have in another room, the image is aways perfectly at the center. The image shift noticed also spontaneously by a friend, without me telling him of its existence. I even swapped the two stereo sets, only to see the problem remain.
So in conclusion It looks obvious that the room and the unhappy positioning of my stereo set are the culprit, but there's an interesting thing to say: no matter how carefully I measure the frequency response of the left and right speaker in my seat position, using a fairly highly accurate measurement setup, the frequency responses of the left and right speaker appear absolutely balanced. On the contrary, when I lower the gain of the right channel by 2.8 dB to center the stereo image and I take a measurement, they appear unbalanced,, obviously with the left about 2.8 dB louder of the right.
My humble conclusion is that sadly, not all the effects of the room and speaker placement can be captured in measurements. More likely, particular ways of measuring the frequency response of the system that can reveal such imbalances may exist, but I am not aware of them.