Is Audio Science Review going about it all wrong? Or partly wrong? Or all right?

[amirm]

I'm reminded of all the information about viewing distance from a hidef TV. Like https://www.rtings.com/tv/reviews/by-size/size-to-distance-relationship
The eye can only resolve so much, so the story goes.
But I drew a single-pixel-thick black line on a white background on my old 46" 1080P Samsung. I could see the line easily from 30 feet away, but a 46" 1080P screen is supposedly only worth it from about 9 feet away.

Those calculators are not very accurate. Your vision low pass filters the signal so it is not a binary thing. You start to lose contrast (modulation transfer function) gradually depending on distance. How much low pass filtering you get is viewer dependent.

Your test is also not very good. Put up a pattern that is one pixel on (white) and one pixel off (black). Stand right in front of the set so that you can easily see them separated. Then take steps backward until you can no longer see the gap. That is the limit for you. Last time I did this test with my 4K TV, I could outperform the online calculators just as well but nowhere like what you are stating.

 

[beefkabob]

The proper test would have been a pair of lines adjacent to each other. Separated by one pixel of white. Could you see (resolve) those as separate from 30 feet away? I think somewhere closer they would have merged together on you. The length of the line obviously is more than one pixel.

The measurements of voltage are simple. Pick a few pieces of music or one at least and set it to a comfortable loudness for yourself to listen to it.
Now play the tone and measure voltage. When you swap components use the same tone to get back to the same voltage.

If one channel is louder, you need to adjust the other component to have the same loudness separately for each channel. How you do this will depend upon the gear in your system. Might be in the playback software with a balance control.

I also might add the second rule of listening comparisons. If there is a real difference when level matched, it is almost always a frequency response difference. Not always, but the great majority of the time. The saying "hifi is 85% frequency response" comes from this idea. Some of the gear in your original post almost surely interacted with the speaker to cause a FR difference that likely was audible.

That wouldn't be a proper visual test, just a different one. Despite all the standard explanations, I could still see the 1-pixel-wide line from a great distance. It shows that the narrative is incomplete.

Well, then this gets harder and harder. Is a software adjustment of volume not going to affect the sound? I'd think it would. Otherwise we'd have all software volume control, which is far from standard in the industry. I think a perfect AB is close to impossible.

 

[beefkabob]

Those calculators are not very accurate. Your vision low pass filters the signal so it is not a binary thing. You start to lose contrast (modulation transfer function) gradually depending on distance. How much low pass filtering you get is viewer dependent.

Your test is also not very good. Put up a pattern that is one pixel on (white) and one pixel off (black). Stand right in front of the set so that you can easily see them separated. Then take steps backward until you can no longer see the gap. That is the limit for you. Last time I did this test with my 4K TV, I could outperform the online calculators just as well but nowhere like what you are stating.

Again, that's just a different test. Not really a better one. The story is incomplete. If I can resolve that line, I'm getting something from a 1-pixel-wide line at a great distance. I'm not getting the full resolution, but I'm getting a benefit from the resolution nonetheless.

 

[watchnerd]

All of this aside, soundstage is in the music. For sound reproduction, we can modify that with different levels in each channel or delay. Both of these are very easy to measure.

Even this can be a matter of artiface.

An old trick I learned from a Bob Katz lecture was that a mixer / recording engineer / mastering engineering can move the perceived imaging (either of a particular instrument track during mixing, or the whole enchilada during mastering) backwards and forwards via PEQ with Fc at 1600 Hz, Q of 1.00, and +/- 2 dB of gain.

 

[beefkabob]

Has anybody looked at patents by Dolby and similar for surround sound and other effects? Frequency boosts and cuts, delays, echos?

 

[Blumlein 88]

Even this can be a matter of artiface.

An old trick I learned from a Bob Katz lecture was that a mixer / recording engineer / mastering engineering can move the perceived imaging (either of a particular instrument track during mixing, or the whole enchilada during mastering) backwards and forwards via PEQ with Fc at 1600 Hz, Q of 1.00, and +/- 2 dB of gain.

I've done exactly this in about that frequency with room correction. To move the image where the listener preferred it. If you expand it over a wider range it doesn't even take 2 db to work. I just stumbled across it accidentally.

 

[solderdude]

About hearing below the noise floor.
It is possible to hear a single tone or a few single tones and detect it below the noise floor especially when switching it on and off.
(Also, with the right tests you can still measure these tones at levels where you will only hear noise.)
Those tests will give you proof that we can hear below the noise floor.
The problem is when you use music there are no constant tones and when peaks in the music reach audible levels you may hear 'something' but it sure isn't music nor can you recognize it as such.
You can easily create such a test yourself and is very enlightening.

The same goes for distortion. One may well hear distortion of a single tone (by adding harmonics) down to very small levels when it is not masked.
But music is not steady state and there are tons of frequencies that will mask distortion products.
So one may be able to hear 0.001% in a study but not hear 0.1% of specific types of distortion but may be able to hear 0.01% of a different type of distortion.

To test yourself there are tons of audibility tests around on the web. There are threads about audibility hear on ASR with links.
This (and properly done 'blind' tests) have given me much insight in what matters and what is audible and what not at least to me.

When using music to prove we can detect >20kHz make sure you analyze the used tracks to see IF they have US content. There are quite a few (good sounding) > 48kHz sample rate files out there that are simply 44.1 or 48kHz recordings and drop off steeply above 20kHz.
The fact that one can hear differences (with certain DACs) between a real CD and its hires counterpart via the same DAC may well be caused by the filtering used or even a slightly (but audible) change in a remastered hires file.

Include in your tests also the 'I will switch cable now' and fiddle on the back of the speakers and amps pretending to hook up another cable (put some zip cord alongside the cables) while doing nothing in reality.
The results are very interesting but don't tell folks afterwards you did this.

Testing people and yourself is very educational but as soon as you have a level just slightly wrong or did not use the right equipment the results ca be all over the place.
Been there, done that.
I know how to fool people and myself and that it is incredibly easy. I also know that using music and test tones gives very different results. I know my audible limits and those of 'general public'.
I also learned not to say to audiophiles they are wrong and when proven wrong in a test they will still go on about their hearing capabilities and just say the test was rigged or use a plethora of excuses.

The only 'win' you will have is that you will learn audibility thresholds and you will find they aren't anywhere near where one expects them to be.

Succes with your tests... make darn sure they are performed properly though or you will end up believing interlink cables can sound very different for instance.

 

[beefkabob]

The proper test would have been a pair of lines adjacent to each other. Separated by one pixel of white. Could you see (resolve) those as separate from 30 feet away? I think somewhere closer they would have merged together on you. The length of the line obviously is more than one pixel.

To add on to this...
Could I perceive the difference between two lines separated by one pixel versus a single line two or three pixels wide? Perhaps the thickness would appear the same, but perhaps the color would seem different? The fact that I can perceive a single line from 30 feet means that the single line carries information to my eyes. How much then?

 

[RayDunzl]

The fact that I can perceive a single line from 30 feet means that the single line carries information to my eyes. How much then?

You (at least me) can't perceive the three colored lines that make up a white line on the screen from 3 inches .

Hopefully, you can fit that into your theory someplace.

 

[dmac6419]

Great Site w/o all the BS, I'm not looking for art or what looks pretty just functional and fair.

 

[Soniclife]

Again, that's just a different test. Not really a better one. The story is incomplete. If I can resolve that line, I'm getting something from a 1-pixel-wide line at a great distance. I'm not getting the full resolution, but I'm getting a benefit from the resolution nonetheless.

Amir's test seems perfect to test for pixel visibility to me, your test isn't because a line is not a pixel.

 

[Soniclife]

That said, I'm totally interested in doing an AB test. Anybody in the SF Bay Area, preferably East Bay, wanna help me do it?

Hope you can get that worked out.

Have you tried comparing music files with software abx, using something like foobar? Teaches you how the process works, and does not involve anyone else so, you can drive yourself mad at a time convenient to you.

 

[JJB70]

In some ways this whole argument cuts to the heart of what the hobby is about. Is audio equipment a tool to facilitate enjoyment of music (or spoken word, or movie/TV sound tracks etc), or is buying equipment the hobby? If you want something to just facilitate listening to material without feeling that the equipment is coming between you and the material then you really don't have to spend much. Even for speakers, good but modestly priced speakers can perform really well if well set up. And on headphones, despite the rush into ever more expensive models and embracing lot's of audiophile snake oil gimmickry you can buy a pair of headphones which will perform as well as (and better) then anybody needs for a remarkably modest cost given how silly prices have become. Sennheiser often sell B stock HD6x0 models at very attractive prices and plenty of dealers run offers on them, ditto for good models at similar price points from AKG, Beyerdynamic, Audio Technica etc. I've even listened to a few sound bars lately which actually performed very well and allowed me to enjoy music without feeling that I was being short changed by listening to it played through a sound bar.
On the other hand, some undoubtedly see the equipment itself as the hobby, and there is nothing wrong with that. I always say that despite recognising that it is not necessary to buy such gear if only wanting to enjoy music that I would like an Accuphase set up or a Benchmark DAC. That may sound contradictory, advocating that if you just want to enjoy music then a lot of hi-fi stuff is basically hocus pocus and then saying I could happily buy stuff from more expensive producers but I do think that good industrial design, build quality, tactile feel and the satisfaction of knowing the product is the result of a real depth of engineering brings a pleasure of its own. What I wouldn't claim is that I would buy such gear to get better sound quality as audibly transparent DACs especially really do cost peanuts. I like the March Audio DAC as that seems to sit in a very nice sweet spot of great industrial design and at a price which is very attractive, offering the tactile feel of expensive products for a price which isn't silly.
If people do enjoy the high end of hi-fi then that is entirely their prerogative. If they enjoy it because they value status symbols (similar to expensive watches and shirts with a crocodile over the tit), or for exclusivity, or for the design and feel or simply because, well hell I got the money and it's my decision how I spend it, then fine. Nothing wrong with any of that. What I do object to is pushing ideas aimed at convincing people that expensive = better and cheap = crap in terms of sound quality.

 

[Shadrach]

I want to start a crusade that everyone interested in high quality audio reproduction should try a level-matched double blind listening test sometime in their lives. For me it was very enlightening and really helped my thinking about audio electronics. And made me a more relaxed and happier listener.

I set up these kinds of tests for myself as a young adult using an amplifier switchbox I made. I took my switchbox to a couple of friendly audio salons that had very good speakers that were set up well. I compared a 70 watt JVC receiver and an 80 watt Sansui integrated against the TOL high-end preamps and amps they had at the salons. I couldn't hear any differences (a long as we kept volumes below clipping). The salespeople thought they could but they didn't do any better than random guessing and gave up pretty quickly. To me the lack of difference was definite and, well, liberating. I had heard very clear differences in sighted tests.

tl:dr I heard all sort of differences in electronics until I did fair blind comparisons. After that, it was clear that speakers, acoustics, and source material were a better place to focus.

What we found with ABX is using the standard procedure almost inevitably left the unconvinced, unconvinced. There were always reasons why their kit was in fact better and despite failing to identify their equipment they would leave such tests believing that the test was in some way flawed or one of my favorites, all ABX tests give null results so they don't prove anything.
Even here on ASR despite the rhetoric its obvious form learning about what equipment people are using that buried deeply in their beliefs is that somehow there is really a difference that is audible.
One technique we found useful was to demonstrate that differences could be heard if they were there in an ABX test. One method was to use one amplifier that would distort and then clip with tracks with a wide dynamic range. When the volume levels were set within 0.5db but at high enough levels to ensure one amp would clip while the other wouldn't. By gradually lowering the matched volume levels ot became more and more difficult to tell one amp from another but you had proven the point that the test was capable of showing differences.
Another 'game' was to have two copies of a particular album. If my memoery serves me we found Steely Dans album Gaucho good for this; one being the MFSL copy and the other a standard issue. This tended to be quite easy to pick out. However, convet one of the albums to mp3 and try to pick between redbook and mp3 of the same album proved more difficult.
Being relaxed at such a test makes things easier. One of my friends made a random switching device and we just plugged this into the system and listened to music while we did other things. You could hear when the switch operated and we would try and guess which bit of kit was playing.
There are lots if inventive games one can play with ABX testing that don't require being sat under pressure in the optimal position with something to prove.
Over the years of our small club meetings we did get quite a few 'passes'. What I learn't was there are differences in pieces of replay equipment that can be heard in an ABX test, but the differences are very small in any competently designed equipment.

 

[HammerSandwich]

What we found with ABX is using the standard procedure almost inevitably left the unconvinced, unconvinced.

JA's latest column illustrates exactly this (and includes his Quad 405 story again).

 

[SIY]

That was a delightful bit of mendacious prose. I especially like how he left out Holt's thoughts on controlled listening tests and the destruction of the credibility of the high end audio niche.

 

[HammerSandwich]

In fairness, he has covered that bit repeatedly, too. (Between the op-eds & flowery reviews, you begin to suspect that certain writers are paid by the word...)

That said, I found this conclusion the most interesting bit:

...even when a real difference exists, it is very difficult to produce anything but statistically null results...

I'm not sure what kind of differences JA means here. Certainly not FR or absolute level differences between the components - blind tests expose those ruthlessly. Seems probable that it goes back to @Shadrach's point. IMO, when "real differences" between components are so difficult to hear blind, sensible audiophiles will focus their attention on other parts of their system. And doubly so once they consider @Floyd Toole's Circle of Confusion.

 

[SIY]

"..even when a real difference exists, it is very difficult to produce anything but statistically null results..."

Bullshit. There's no other word for it.

But maintaining that facade despite knowing better is what has made him a millionaire.

 

[amirm]

Again, that's just a different test. Not really a better one.

It is the other way around. The test I mentioned is the standardized one for detecting the resolution that you can resolve. One pixel on/one pixel off is the maximum (spatial) resolution you can have in a display. It would be to audio as if we had a 22.05 khz signal to detect if we can hear half the sampling frequency at 44.1 kHz.

A pattern where you had a multi-pixel black line against the white background only pushes the spatial resolution at the edges (i.e. reduced MTF). Elsewhere it represents a lower resolution signal. We all can see and detect images on a TV at 30 feet away. So seeing something is not evidence of you detecting the actual resolution. And as such, it doesn't invalidate the online calculators. Those calculators are based on resolution limits of the average human vision, not at some other lower point.

 

[Soniclife]

I am replacing my mostly 20-year-old system. McIntosh bookshelves, Carver power amp, Chase preamp, and LG CD player.

I would think that the amps might be worth keeping, they may need a service, which needn't be expensive.