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Imaging and soundstage. What are they and who hears them?

krabapple

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Find a source that has imaging tests. The better ones have signals to test imaging 'outside' the L/R speakers, as well left, center-left, center, center-right, right . And all the other comninations, if it's a surround system.

Performance on these is a function of the loudspeaker placement (and phase, which you've checked), listener position, and room acoustics , not the amp. Don't listen to your brother, test it properly.
 

DVDdoug

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This is mostly redundant, but...

Of course it's an illusion! With regular stereo there are only two speakers (two sound sources). It depends on the listener's perception, the recording. and the speakers and all of the other things that affect the way the sound "bounces around" the particular room.

We also tend to over-estimate our ability to locate sounds... If you've every tried to locate a rattle or squeak in your car (or similar situation) it's not always easy!

There's no logical reason for a properly functioning amplifier to make a difference. Of course, you could have an imbalance (one channel louder than the other) or poor separation (sound leaking from one side into the other) but those effects are not audible unless the amp is badly defective. Phase only has an effect if there is a phase-difference between channels. You don't get much phase shift in an amplifier and it's almost impossible to get a different phase shift the left & right channels. (Of course, you can can reverse the connections to one speaker to make the speakers out-of-phase/polarity.) The crossovers in your speakers will introduce far more phase shift than an amplifier anyway. But since both speakers are (hopefully) the same, it's not an issue.

Some people get a "soundstage" with headphones. I don't. I hear hard-panned sounds (somewhat rare in modern recordings) coming directly from the headphone and "injected" into my left or right ear. I hear other sounds coming from somewhere around my forehead. And different headphones don't make a difference... I never get a realistic soundstage. This is not a big "problem" for me. I don't listen to headphones that much, and when I do, it's just a "different experience". I also did some experiments with Dolby Headphone and a test DVD... I didn't perceived sounds coming from behind like with actual surround speakers. (Dolby doesn't actually claim that Dolby Headphone creates true-surround.)

On the production side, sounds are normally panned (positioned) between left & right with a pan pot that increases the volume on one side and decreases the other, I read about an experiment that had surprisingly "inaccurate" results. He does some further experiments with time delays and gets better results/ And you do get the time delays if you make a recording with stereo microphones, but very few modern modern recordings are made that way. Most recordings are multitracked and mixed/panned to stereo.
 
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FeddyLost

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Who is right?
The one who paid for product that keeps him satisfied.
It's the ultimate goal of any home hi-fi system.

Can two people listen to the same thing and hear two totally different things?
For sure. Psychoacoustic is a tough thing.
I can make some assumptions, but only after excluding idea about sighted bias.

How can an amplifier (especially an amplifier that measures as well as the Purifi based amps) collapse a soundstage and imaging?
Purifi measures good at quasistationary signals.
We don't know how exactly it renders transients paired with your Magico.
But also i can imagine that higher distortion of Accuphase adds some "spatial" qualities to "flat" tracks while Purifi plays them "as is" = flat.
All this is just speculation until we validated that something really "collapsed".

In my opinion imaging is mostly result of proper record and speakers+room properties. If your system never had exemplary spatial imaging or tracks are "artificially spatial" (= not stereo miked live performance) there's just nothing to collapse.
 

richard12511

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An amp shouldn't affect soundstage/imaging at all unless it amplifies the channels unequally. Soundstage and imaging are determined by speaker/listening position, room acoustics, and the loudspeaker's radiation pattern. The amp cannot possibly affect these things, so it really shouldn't affect imaging. I think it's far, far more likely that the "soundstage differences" your brother heard are a result of his brain and it's biases. Test him blind, and see if he can still tell them apart. If he can't, then you know there is nothing wrong. If he can, then there very well may be something wrong with the March Audio amp. In that case I would see if you can get it measured to diagnose the problem. There could also be setup related issues at play here(not necessarily a broken amp).

Really important to realize that amp sound differences(when they do exist) are going to be very small(ex: 0.1dB less above 10khz). On the other hand, human brain generated differences(placebos) can be huge; many many times the size of any amp differences, and often larger than even speaker differences(5 dB+). If you're trying to compare 2 good amps by listening to them sighted, then your brain is likely accounting for 99%+ of the difference in sound. That variable really must be removed if one wants to hear the tiny(0.1dB or less) differences that exist between two excellent amps.
 
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richard12511

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What Paul McGowan has to say on the topic-

This guy has shown on so many occasions that he really has no clue what he's talking about in many circumstances. He's trying to sell you his way overpriced products that perform worse than much cheaper options. Only way he can sell such goods is if he gets you to believe he knows some "magic" that he imparts on his electronics. Evidence from him is more like counter-evidence in my view ;).
 

gsp1971

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To my limited knowledge 'soundstage' and 'imaging' apply to speakers: directivity, off-axis response, room placement, etc. as well as room acoustics.

In your case: same room, same (excellent) speakers, same placement, resulting in different perceptions of soundstage and imaging based only on an amp change, must surely have to do with the persons involved rather than the equipment.

Perhaps if you ask @amirm for a couple of selected tracks from his reference list that he uses to gauge imaging and soundstage, and then have another session with your brother listening to these specific tracks, can help resolve the issue?
 

Chromatischism

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This guy has shown on so many occasions that he really has no clue what he's talking about in many circumstances. He's trying to sell you his way overpriced products that perform worse than much cheaper options. Only way he can sell such goods is if he gets you to believe he knows some "magic" that he imparts on his electronics. Evidence from him is more like counter-evidence in my view ;).
Who knows, he may be right that reducing feedback does what he says, but maybe it's because it jacks up the frequency response. If that's the case then we aren't keeping this down to only 1 variable.
 

Grumpish

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But also i can imagine that higher distortion of Accuphase adds some "spatial" qualities to "flat" tracks while Purifi plays them "as is" = flat.

I didn't start playing with valve amps until four or five years back, and the imaging was the first thing that struck me when I hooked my first one up - and no, it was not an expectation bias, it was actually quite unexpected. So the increased distortion adding something could be a viable explanation. That said, I only hear any noticeable depth on a very few, and mainly older, recordings, such as Billie Holiday's Lady in Satin. And these days my hearing is rubbish, so anything I say has to be taken with a pinch of salt.
 
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a.dent

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I didn't start playing with valve amps until four or five years back, and the imaging was the first thing that struck me when I hooked my first one up - and no, it was not an expectation bias, it was actually quite unexpected. So the increased distortion adding something could be a viable explanation. That said, I only hear any noticeable depth on a very few, and mainly older, recordings, such as Billie Holiday's Lady in Satin. And these days my hearing is rubbish, so anything I say has to be taken with a pinch of salt.
The Accuphase A-70 has very low distortion. Sure, the March should measure a bit better but not much.
Amir’s measurement of the bottom of the range E-270 still put it at the top end of the green”very good” section. The A-70 measures better.
I’m convinced that it is more than a distortion difference but that is probably playing a part.
 

IronPyrite

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Are you sure your brother is not bullshitting you? It has been known between siblings … ;-)

If 'soundstage‘ or ‘imaging’ are a thing then they are 99.99% a property of the loudspeakers - their placement in the room, directivity, phase alignment etc. I doubt two excellent amplifiers would make the slightest difference in that respect.

Otherwise, how long is it since your brother last heard your gear before getting the March? Had you changed anything else since he last heard it? Even if nothing changed, audio memory is famously fickle. Without blinded and level matched tests niether of you can be really certain ...
This is my experience as well, although I'd also allocate 20% for room acoustics (e.g. one speaker closer to the wall) and some small but non-negligible % for channel separation in the audio chain. For speaker placement, my method is to do the following, the effort is usually well worth the end result.

1. Get out some masking tape and make a line on the floor between you (listener) and the plane of the speakers (like the blue tape on the floor of Paul's video).

2. Use a carpenters square to make another line perpendicular to the first line, which will represent the front plane of the speakers.

3. Ensure both speakers are precisely equidistant from the first line, and at the same distance from the 2nd line.

4. Toe in and out both speakers to find the imaging sweet spot. Make sure both speakers have the same toe in/out angle - if you can't measure this effectively, eye-ball it by walking back the first line to the convergence point (or as best as you can, if your back is against the wall). Too much toe-in, and the sound will be very focused, but lack sound stage. Too much toe-out, and you'll have better sound stage at the expense of any "phantom center" effect (i.e. a front stage singer will sound like she/he is singing across the stage, rather than standing in the center).
 
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a.dent

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This is my experience as well, although I'd also allocate 20% for room acoustics (e.g. one speaker closer to the wall) and some small but non-negligible % for channel separation in the audio chain. For speaker placement, my method is to do the following, the effort is usually well worth the end result.

1. Get out some masking tape and make a line on the floor between you (listener) and the plane of the speakers (like the blue tape on the floor of Paul's video).

2. Use a carpenters square to make another line perpendicular to the first line, which will represent the front plane of the speakers.

3. Ensure both speakers are precisely equidistant from the first line, and at the same distance from the 2nd line.

4. Toe in and out both speakers to find the imaging sweet spot. Make sure both speakers have the same toe in/out angle - if you can't measure this effectively, eye-ball it by walking back the first line to the convergence point (or as best as you can, if your back is against the wall). Too much toe-in, and the sound will be very focused, but lack sound stage. Too much toe-out, and you'll have better sound stage at the expense of any "phantom center" effect (i.e. a front stage singer will sound like she/he is singing across the stage, rather than standing in the center).
Yep.
I‘ve done all that almost exactly as you have described.
The room is symmetrical 6m long and 4.5m wide. Maybe the side seating is not perfectly symmetrical but pretty close. It’s a dual purpose room as you can see.
164DA650-5C38-4E58-99CA-2902BEDF7053.jpeg
 

Daverz

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His first comments on hearing the P 452 in my system were "That sounds terrible. The soundstage has collapsed and the imaging has disappeared. There must be something broken in the amp. I'd send it back and get them to check it. Sounds like the phase has been mucked up. The Accuphase is way better."

Did you let slip that you'd bought the amp based on ASR recommendation? Then probably in his mind it's not a "proper" high-end amplifier and must sound bad.
 

jtgofish

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There are just so many variables and considerations-
Not everybody has the same hearing.
Not everybody listens in the same way for the same things.It is arguable that like wine tasters some people probably have the capacity to refine or train their hearing to be more sensitive to relatively small differences.
People have different expectations of how things should sound based on past experience and preferences.Including cultural and even physiological differences .
People use very different types of music and recordings to try to reference what they think they should hear or want to hear.What people expect from listening to an orchestral recording [Bose 901s anybody?] will be very different to closely miced small ensemble recording in a small space.
There is not a standard in which source/preamps and power amps interact with each other electrically because there are loose electrical standards for these things.That is highly likely to produce interactional differences in sound .
How amplifiers and speakers interact electrically is highly variable because speakers have highly variable impedance, driver efficiency and crossover networks that cause phase shifts.Given these factors amplifiers which are completely voltage drive will sound very different to those that are current drive or a mix of voltage and current drive [a lot of valve amps].
Power supply factors.

And I am sure there are a great many other such variables.
 

LTig

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There are just so many variables and considerations-
Not everybody has the same hearing.
Not everybody listens in the same way for the same things.It is arguable that like wine tasters some people probably have the capacity to refine or train their hearing to be more sensitive to relatively small differences.
People have different expectations of how things should sound based on past experience and preferences.Including cultural and even physiological differences .
People use very different types of music and recordings to try to reference what they think they should hear or want to hear.What people expect from listening to an orchestral recording [Bose 901s anybody?] will be very different to closely miced small ensemble recording in a small space.
Agreed.
There is not a standard in which source/preamps and power amps interact with each other electrically because there are loose electrical standards for these things.That is highly likely to produce interactional differences in sound .
Those would be either to much noise or clipping, in case of a bad gain chain. However as long as you don't mix balanced and unbalanced IOs those "loose" standards are good enough that this won't happen.
How amplifiers and speakers interact electrically is highly variable because speakers have highly variable impedance, driver efficiency and crossover networks that cause phase shifts.Given these factors amplifiers which are completely voltage drive will sound very different to those that are current drive or a mix of voltage and current drive [a lot of valve amps].
Power supply factors.

And I am sure there are a great many other such variables.
Power Amplifiers using current drive are not suitable for driving speakers. The same is true for voltage driven power amps with too high output impedance (designs with low or no feedback or SE triode amps coming to mind). The power supply has no influence on imaging, nor any other unknown variables within the electronic chain.
 

jtgofish

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Power Amplifiers using current drive are not suitable for driving speakers. The same is true for voltage driven power amps with too high output impedance (designs with low or no feedback or SE triode amps coming to mind). The power supply has no influence on imaging, nor any other unknown variables within the electronic chain.[/QUOTE]

Really?
Thankfully not everybody is so dogmatic about such things .

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiQnJbZ5LHyAhXBILcAHR3jB7MQFnoECAMQAQ&url=https://www.sgraudio.com/sgr-audio-announces-limited-edition-current-drive-upgrade-for-its-cx3b-mk1-and-cx3c-mk1-active-loudspeakers&usg=AOvVaw0Z7f-UaXthHivtG138XGxP

And this-
http://education.lenardaudio.com/en/12_amps_8.html
 
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