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Absolute Phase: The Next Frontier (yeah right) - Page 2

post #16 of 36

Quit griping. Sauce for the goose is sauce for the gander.

 

Given the large numbers of spurious claims we encounter you should be disappointed if yours is examined any less rigorously.

 

I am simply asking questions I would expect you to ask, and consequently have a ready answer for. What measures were taken in these tests to ensure that there was no transducer-introduced effect? Or is it widely accepted that what you generate mathematically will be reflected in the pressure at the hearers eardrum? 

 

It's just that, looking at your waveform, I'm thinking, what could upset the perception of volume in this case? Or the actual volume of the components? The first thing that occurs to me is an assymetric excursion of the driving element. Such as might occur if the signal had a DC offset? 

 

With regard to the miking of the drumkit, I couldn't agree more.

 

w

post #17 of 36

it isn't my claim - it is from reading the literature - for the basic physiology of hearing supporting the ability try auditory nerve fiber phase locking in search - peer reviewed papers, "textbook knowledge" by now

 

Quote:
The other prominent feature of hair cells—their ability to follow the waveform of low-frequency sounds—is also important in other more subtle aspects of auditory coding. As mentioned earlier, hair cells have biphasic response properties. Because hair cells release transmitter only when depolarized, auditory nerve fibers fire only during the positive phases of low-frequency sounds (Figure 13.10). The resultant “phase locking” that results provides temporal information from the two ears to neural centers that compare interaural time differences. The evaluation of interaural time differences provides a critical cue for sound localization, by means of which a person is able to perceive auditory “space.” That auditory space can be perceived in this way is especially remarkable, given that the cochlea, unlike the retina, cannot represent space directly.

 

10 Temporal response patterns of a low-frequency axon in the auditory nerve. The stimulus waveform is indicated beneath the histograms, which show the phase-locked responses to a 50-ms tone pulse of 260 Hz. Note that the spikes are all timed to the same phase of the sinusoidal stimulus. (After Kiang, 1984.)

 

 

http://www.ncbi.nlm.nih.gov/books/NBK11105/  perhaps more recent textbooks than when some of us went to school - but a diploma is no reason to stop learning

 

 

 

it is expected that HD-600 at ~100 uW are pretty linear (98 dB/mW and I was certainly not listening at over 80 dB), <0.1% from Tyll's measurements http://www.innerfidelity.com/content/very-important-sennheiser-hd-580-hd-600-and-hd-650-measurements 

 

I suppose I could repeat with Koss ESP-950, or how about SR-007 MK-1 (but from the Koss E/90)


Edited by jcx - 4/20/14 at 4:55pm
post #18 of 36

Excellent, thank you, no, that will do.

 

I was pretty convinced anyway, but that provides quite a lot of substantiation.

 

You are a mine of information, it's just that getting at it can be like pulling teeth.

 

w

post #19 of 36

I am in complete lost after reading the article. I fail to understand the last bits.

Isn't the  Fletcher test testing for any phase difference between two speakers?

Regarding the Haas effect, if you sit in front of one speaker, the other speaker is probably further from your head, hence a small timing difference between two sound sources.

Maybe I misunderstood the whole thing.

post #20 of 36
Thread Starter 
I seriously doubt that absolute phase is audible in music, and even more doubtful that it can be heard with music on speakers. I think this whole thing is snake oil. The description in the article for how to "train" yourself to hear phase seems to me like a recipe for placebo.

I can see hearing the difference between in phase and reversed absolute with headphones and test tones or specific types of sound. But in practice, it's a gnat wing.
post #21 of 36
Quote:
Originally Posted by bigshot View Post

I seriously doubt that absolute phase is audible in music, and even more doubtful that it can be heard with music on speakers. I think this whole thing is snake oil. The description in the article for how to "train" yourself to hear phase seems to me like a recipe for placebo.

I can see hearing the difference between in phase and reversed absolute with headphones and test tones or specific types of sound. But in practice, it's a gnat wing.


Sure, but if it is actually audible, I think it is something that should be a consideration for a true high-fidelity system. It might be subtle, but the goal of high-fidelity audio reproduction (in my opinion) should be audible perfection - in other words, any potentially audible degradation of the sound should be fixed. This of course does not include such nonsense as $20k cables and ultra-high bitrate files, but if absolute phase is provably audible, that puts it in a very different category from something like 24/192 files (which have never been successfully detected in an ABX).

post #22 of 36
Thread Starter 
That article claims that you need a phase switch because from song to song on the same album phase can be switching back and forth. That is untrue, and even if it was, all the elements in the mix would probably be mixed up too, so the same song could have parts that are both in and out of phase. Sorry. No one needs a phase switch.

Just because something is audible in test tones (just barely and only with certain unusual shapes of waveforms), it doesn't mean that it makes any difference at all when you listen to music. Any amount of reverberation built into the track or super slight phase differences between multi-tracked mixes are going to muddy the waters completely. Take ten different songs and switch the absolute phase on one of them randomly. I defy anyone to be able to detect inverted phase consistently. It just isn't an issue. Hook your speakers up with the plus in the red terminal and the minus in the black one and you're fine. That's as much as you have to think about it.

The theory that "if you can hear it at all, it matters" is the one that leads people down the garden path of chasing after subtle differences that don't mean jack diddly. Great sound is achieved in the broad strokes and overall architecture of the sound, not the details clustered around the edges of your ability to hear. There's always something bigger that needs addressing. If you waste time on diddly stuff, you'll never have great sound.
Edited by bigshot - 4/21/14 at 10:58am
post #23 of 36
I've got to agree with you 99% on this. For the enjoyment of any music, or in terms of post production to print and playback, absolute phase is a non issue and from what I hear in DBT is not detectable as soundstage or overt spectral changes. However, I was able to very quickly find an example with real music in which I can detect a difference and with near certainty tell which is which. Even more so now that I tortured myself listening to this example for far too long.... I would say that absolute phase is easily detectable in some cases of low frequency transients on any gear, including speakers and iPods. The difference was actually more noticeable on my Mission 700 bookshelf setup. Listening both ways is equally enjoyable to me. This is one of the few times where conducting DBT myself confirmed something I thought to be false. This is one case where just setting up a system for non inverted operation is easy and good enough for me, and also free. Also agree that a phase switch is nonsense/snake oil. smily_headphones1.gif
Quote:
Originally Posted by bigshot View Post

I defy anyone to be able to detect inverted phase consistently. It just isn't an issue. Hook your speakers up with the plus in the red terminal and the minus in the black one and you're fine. That's as much as you have to think about it.
The theory that "if you can hear it at all, it matters" is the one that leads people down the garden path of chasing after subtle differences that don't mean jack diddly. Great sound is achieved in the broad strokes and overall architecture of the sound, not the details clustered around the edges of your ability to hear. There's always something bigger that needs addressing. If you waste time on diddly stuff, you'll never have great sound.

Edited by GrindingThud - 4/21/14 at 3:28pm
post #24 of 36
Thread Starter 
I'm curious if anyone has ever found a recording of music that has reversed phase. I'm betting the answer is no. I'm also betting that if such a recording does exist, it really doesn't matter because it sounds as good out of phase as in.
post #25 of 36

it is likely the effect of training to hear a very specific and subtle feature of sound will fade if you don't continue the focus/exercise, quit bringing the distinction to conscious awareness

 

 

clearly a kick drum's orientation to the live performance listeners can give a unambiguous absolute polarity - but the mic might be on the wrong side! http://www.dummies.com/how-to/content/microphone-placement-for-kick-bass-drum.html


Edited by jcx - 4/21/14 at 3:46pm
post #26 of 36
Or, that it was done intentionally and sounds better that way as designed by the recording engineer. smily_headphones1.gif
http://www.better-records.com/product.aspx?pf_id=grusidisco_phase (warning snake oil inside)
http://www.dccblowout.com/search.asp?so=3&si=**&sp=outofphase&GO.x=12&GO.y=9
Quote:
Originally Posted by bigshot View Post

I'm curious if anyone has ever found a recording of music that has reversed phase. I'm betting the answer is no. I'm also betting that if such a recording does exist, it really doesn't matter because it sounds as good out of phase as in.

Edited by GrindingThud - 4/21/14 at 4:03pm
post #27 of 36
post #28 of 36

I'll have to see if I can find my password/id - that needs an edit, Doug's speculation is just plain wrong - I already posted the 2-tone test and illustration in the other thread here http://www.head-fi.org/t/486598/testing-audiophile-claims-and-myths/2475#post_10392236, hmm, the animation seems to have been lost

ab intio also put up some sawtooth like tonal polarity tests


Edited by jcx - 4/21/14 at 8:16pm
post #29 of 36
Quote:
Originally Posted by jcx View Post

I'll have to see if I can find my password/id - that needs an edit, Doug's speculation is just plain wrong - I already posted the 2-tone test and illustration in the other thread here http://www.head-fi.org/t/486598/testing-audiophile-claims-and-myths/2475#post_10392236, hmm, the animation seems to have been lost
ab intio also put up some sawtooth like tonal polarity tests


The sound clips are basically the different phases/polarities from the animation. They are linked in the post here. Let me know if any of the links are broken.

Cheers
post #30 of 36
Quote:
Originally Posted by bigshot View Post

I'm curious if anyone has ever found a recording of music that has reversed phase. I'm betting the answer is no. I'm also betting that if such a recording does exist, it really doesn't matter because it sounds as good out of phase as in.

 

http://www.audiocheck.net/blindtests_abspolarity.php

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