The Harbeth forum is back and running now. Folks can now access the original message by clicking the link on the front page of this thread, 4 pages long altogether.
AS has further clarified on his plan and intention in carrying out the listening test in his latest post. If I am interpreting it correctly, he is suggesting an instantaneous changeover with the switch-over box between two amplifiers, and the listening process is just a few seconds before and after the changeover(which takes place in a split second). Perhaps he meant listening to a track for two to three seconds with amplifier A, do the changeover and listen to the same track for another few seconds with amplifier B. Apparently he is not in favour of folks listening to the entire track. If that is the case, obviously no one would win a pair of M40.1.
Message from AS as below. Salient points in bold.
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Just to be clear about this amp comparison subject as I've heard that some other forums seem to have misunderstood our intentions ....
1) We definitely, 100% do believe that people (including me) can, do and will hear differences between amplifiers randomly put in front of us, hooked up, switched on and turned up!
2) We have observed that for psychoacoustic reasons that we do not understand or pretend to understand, when those very same amps are level matched (with test equipment) and then connected to a good quality relay change-over driving one pair of speaker, that when the change-over is operated entirely at random, those big initial differences heard in 1) diminish to little or nothing. So much so that it's actually not possible (in many instances) to hear any discontinuity or change in the music at all, except the minute gap as the relays flick over - perhaps one thousandth of a second. Even that may not be audible. Surprising, yes it is to me as well. This is, I agree, counter-intuitive.
3) We send all those that make amplifiers our good wishes. If the test revealed - and it would be worth at least one pair of M40.1s - that one amplifier was of such easily demonstrable sonic superiority to all other contenders (I'd buy it immediately) it would truly be a match for our RADIAL cone technology. The entire hi-fi industry would have taken a genuine leap forward and a golden nugget revealed which we'd all do very well to buy. I look forward to that revelation. That designer, that company deserve to be hugely successful.
The way things currently stand, every hifi amplifier designer is claiming that his amp 'sounds the best'. That means that, if there really is a golden amplifier amongst the pack, we are missing it due to the marketing clamour surrounding all the other amplifiers. They cannot all 'be the best' can they.
That's our sole point. We wish we understood the human ear better. Exactly why this switch over test 'levels' what are initially significant performance differences is a mystery. Pass this on.
P.S. Link to switch-over box design is here.
P.P.S. As a point of clarification, I never listen to more than a few seconds of music before switching over: listening to an entire track is unthinkable. See the next post ... #44
Tidying up the server just now, I found a PDF containing a video from a few years ago. I'd forgotten that I made this at the previous listening room and I could film this in much better quality now. Apologies for the picture/sound quality.
The way I work is all about instantaneous change-over. I do not trust my own audio memory. This video shows the foot switch in operation (the actual switch-over box is under the speaker stand). It allows me to compare two speakers instantaneously against each other - an M40 v. an M40.1 - then comparing one with a SHL5, and finally one with the M30. No need to move from the hot spot. No need to listen to the same full track (boring, soporific, teaches you nothing - listening at this time is not for pleasure). Just click-click and change over. You may just about be able to hear the difference in sound picked-up by the camera's inbuilt microphone.
So, when comparing amplifiers you use the switch box in reverse: two stereo amplifiers drive one pair of speakers and can can be switched-over to just as fast as you can hear the speakers change over. Completely foolproof. Totally eliminates memory, and most important, emotion, fatigue and attention drift.
Alan A. Shaw
Designer, owner
Harbeth Audio UK
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Personally I cannot fathom this. The instantenous changeover method appears to be regarded as the one and only valid test in authoritatively claiming that differences in amplifiers do not exist. The practice of listening to an entire track, or perhaps a few minutes of a track is not considered as a valid or proper system.
In adopting the instantanenous changeover test, it was mentioned that this would eliminate memory and most importantly emotion, fatigue and attention drift. Again, I am at a loss here. I suppose AS wanted to eliminate the function of short-term memory, a necessary tool in the way the human brain analyses sound wave when it travels to the ear before being transformed into nerve pulses and processed by the brain. With just few seconds of listening to a track, there is insufficient time for the brain to process the potential differences in sound(with the changeover) and store them in memory.
It would be a futile exercise if the test methods can't be agreed upon. From the looks of it, a landslide win for Harbeth if their test method is adopted. Folks who can perceive differences in amplifiers will then be considered as imagining things, listening to differences that do not exist in their heads.
I would like to have a shot at an M30 in tiger ebony, though it appears that Harbeth already have their plan well thought out.
On a separate matter, similarly I was little confused on the earlier statement Harbeth made about (attenuating?) differences in frequency response in amplifiers when they mention about doing the test in a controlled experiment with all variables accounted for. Not too sure if they are planning to disqualify any amp with an irregular or uneven frequency response, or they would insert an equalizer of some sort in the circuit to account for the variations. Again, that would further defeat the purpose of the proposed test.