How do I show ABX test result on several amps with speakers? Record the output and use foobar ABX? Even if it could produce meaningful results, I have no access to an anechoic chamber. I am not aware of any anechoic chamber installation here in Indonesia. Perhaps a recording studio room is good enough, there are some facility I can rent in Jakarta, a city 40 miles north of where I live. Are you willing to invest in an experiment and pay for an access to one, cost of transporting my gears, accommodation and my time for doing stuff of great importance you want? Right, I don't think so. You expect me to go through a great nuissance and pay for the cost just to satisfy your petty need. Nothing important enough for you there, trust your own logic and mine.
I think there’s something to be said for actually having space behind your speakers.
Severe hearing loss can actually make some artefacts audible that "normal" people can't hear. Pre ringing is an example.
Same with very bad equipment, that can show all sorts of artefacts you can't hear on a premium system.
Once your past a certain age, hearing is imparred. A sad fact of life.
Speakers is the one that's most difficult. The rest is easy to record.
But you can make binaural recordings of speakers and test with headphones.
And you can go with what the science dudes are saying. Harman has a speaker-shuffler that can do double blind testing. It's not perfect, but it's the best we have.
I tried and it does not sound the same, way compressed and no 3d soundstage localization worth mentioning.
ABX on amps needs no speaker shuffling but is still rather complicated and not easy to verify the result. If you come to Bogor, Indonesia, perhaps on your way to a vacation in Bali, you can witness the test live, I will build a randomizer box or you can bring your own no problem.
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I understood it fine. The question is if you understood what you proposed. You are the one who championed your subjective listening experience at your own listening environment. Since you have claimed to have heard the difference, surely you can record it there if you are into recording ABX test. For audio ABX results, you should record them on paper to share with others.
Binaural only works if you use your own head and place mics in your ears.
Like these.
https://www.amazon.com/Sound-Professionals-NOISE-BINAURAL-MICROPHONES/dp/B002N6PAMM/ref=mp_s_a_1_3?keywords=in+ear+microphone&qid=1570772999&sr=8-3
For me dummy head binaural recordings create a soundstage that is arced across my skull. I seem to have a weird head.
You can record the output of any amp with a voltage divider. No need for complex stuff.
You seem to over complicate things.
KISS is the first thing you should think about.
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And pass the ABX test flawlessly but meaninglessly due to different background noise during different recording sessions. I highly recommend some thinking before making a comment.
Have not tried in my own ears. Could work but I have no pressing need to do so.
That is not good enough. I listen to acoustic output of speakers. Try a current source amp, the method you proposed falls apart. It has been repeatedly measured that FR and distortion of acoustic output does not reflect amp FR and distortion linearly. Attached is measured acoustic output recorded from 2 amps using a single DX55 driver, done by Nelson Pass in 2004.
Would you still ask people what to listen for when measured FR is clearly different? What should I say to you, an authority recognized within recording community, who professed to have compared amplifiers and perceive no difference?
It took a genius like Bob Carver 3 days of hard work and who knows how much time he spent during preparation for the Stereophile challenge. It certainly is possible to make amps of different topology to sound the same, but not an easy feat.
I agree on the KISS principle, but I also kept in my mind "as simple as possible but no simpler".
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I have no experience with current source amps.
Maybe Mr Pass can comment on this specific problem.
My 2ct output impedance is very different in these 2 amps. But I'm speculating.
The protocol doesn't change.
You must provide enough evidence that YOU can actually hear a difference. Then tell others what to listen for, so they can verify it. Sometimes this is easy, probably in the attached case, sometimes very very hard.
They are great, but similarly to other amps, need some form of compensation around resonance and other strong peculiarities of the driver which is a bit different compared to compensation normally used for voltage source.
Of course, current source is by definition high impedance output while voltage source is low impedance. A bit more on this, Ersa Merilainen published in 2016 his findings on using current drive to reduce acoustic distortion. Pavel Macura measured, confirmed the finding and published his independent measurement result in his website. Richard Marsh published in Audio Amateur in 1985 a similar technique that reduce acoustic distortion from 5% to 2.6% at 45Hz, close to resonance, 90dB SPL. Should nobody can hear any difference, their work and work of many others are for naught. But, not everybody can hear, no matter what, usually we can deduce from his/her posts. It is fine not to be able to hear the difference, even my listening discrimination has dulled over the years. Which actually is an advantage since I now design for more forgiving customers, my own ears. 🙂
I'm sure there is someone who would not be able to hear any difference even on cases categorized as "easy". Unfortunately, the soundstage and localization bit that I enjoy are the illusions not "easy" to perceive.
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'slow' sound is usually a subjective description about dynamics, distortion etc. not anything related to the speed of mechanical processes in a digital data read-back system. The only example I can think of where 'slow' might refer to a physical process is a slow running turntable.
if the 'start of noise' is that which is below the threshold of audibility then it seems unlikely it would be an issue unless it caused IMD products. Perhaps low-level IMD is a better place to look.
“And what is good, Phaedrus,
And what is not good—
Need we ask anyone to tell us these things?” Pirsig again.
Do you have something to hide?
As if you don't understand what ABX report is.
Do you have money to burn? As if you don't understand what meaningless means. You want to commision me to do useless stuff, you pay me to waste my time for you. I accept payment through paypal, send a PM. I guarantee you can also hear a difference. I live next door to a cafe playing music all day long, you can enjoy that as a background and occasional sound of passing cars and motorcycles. I'll do the recording extra special level matched to 0.1 dB just for you.
Result is your property, I keep no backup. You can keep for yourself or share in public forum. Totally yours. 😀
Result is your property, I keep no backup. You can keep for yourself or share in public forum. Totally yours. 😀
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The Dolby system was a great advance to eliminate the noise of the tapes, but it was very misunderstood by the great majority of the "audiophiles" of that time.
"I record with Dolby and listen without Dolby" was a very common phrase in those years. How not to hear "grain" then? (If that can be called that, I think the OP refers to another type of noise, but I want to clarify the point)
What is recorded with Dolby is heard with Dolby, so this ingenious method of eliminating tape hiss was created.
We raise the treble level when recording. (It is a pre-emphasis), I think I remember that it was 3 DB, (this would have to be corroborated by someone, it could be 6 Db) That leaves an exaggerated recording of the treble on the tape. But as the noise of the tape is presented when playing, because it is inherent in its material and its contact with the head when sliding over it) when we play, if we apply the Dolby (de-emphasis) we listen to the actual recording in its levels correct, but tape noise has decreased at the same de-emphasis levels -
Here a good link, use translator, is Spanish.
Noise Reduction in Tape Recording
Regards 🙂
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