| zmix wrote on Wed, 10 February 2010 10:08 |
| Andrew Hamilton wrote on Tue, 09 February 2010 18:40 |
... I'd venture that the big change in the female vocal heft noticed from a very small boost at 30 cycles was more to do with the (un/)masking created by the phase shift introduced by the tweak...
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Care to elaborate on how phase shift causes unmasking?
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While English is not their first language, I think you will see that I am not smoking something (too strong for me, that is...);
http://www.springerlink.com/content/y8865v6511m2672t/
Their experiment is rather similar to what I am describing. I honestly don't know for a fact if what I am suggesting here is balderdash or brilliant, but I _do_ know that when I cut or add only half a dB to a sensitive center frequency on an eq that a complex signal is passing through (as in a channel of an entire mix) - and not all cf's are equally sensitive on a given recording, obviously - there can be more of an effect than should have occurred from the tiny boost, or cut, itself. Therefore, if it's not the frequency change, isn't the only parameter left, the
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« Reply #31 on: February 12, 2010, 06:27:08 AM »
| Andrew Hamilton wrote on Thu, 11 February 2010 22:48 |
| zmix wrote on Wed, 10 February 2010 10:08 |
| Andrew Hamilton wrote on Tue, 09 February 2010 18:40 |
... I'd venture that the big change in the female vocal heft noticed from a very small boost at 30 cycles was more to do with the (un/)masking created by the phase shift introduced by the tweak...
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Care to elaborate on how phase shift causes unmasking?
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Their experiment is rather similar to what I am describing.
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Honestly no. They are referring to spatial localisation helping intelligibility; that's really a property of binaurality. | Quote: |
I honestly don't know for a fact if what I am suggesting here is balderdash or brilliant, but I _do_ know that when I cut or add only half a dB to a sensitive center frequency on an eq that a complex signal is passing through (as in a channel of an entire mix) - and not all cf's are equally sensitive on a given recording, obviously - there can be more of an effect than should have occurred from the tiny boost, or cut, itself. Therefore, if it's not the frequency change, isn't the only parameter left, the
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« Reply #32 on: February 12, 2010, 10:14:25 PM »
| zmix wrote on Fri, 12 February 2010 01:52 |
Are you saying that the article you linked above (here) is somehow related to your assertion that phase shift has an "unmasking" effect?
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Are you saying that it doesn't? Bob Katz has described the phase shift of the affected group as creating a different depth of field for the relevant instruments. This seems rather consistent with physically relocating the masker... Andrew
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« Reply #33 on: February 12, 2010, 10:32:37 PM »
| Geoff Emerick de Fake wrote on Fri, 12 February 2010 06:27 |
Honestly no. They are referring to spatial localisation helping intelligibility; that's really a property of binaurality.
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Honestly, if the listener cups a hand over one ear, eliminating the binaural effect, he would still be affected by masking/unmasking caused by proximity of relative sources... And this is the same thing happening with group delay, but to a complex signal that is already mixed down electrically, rather than one which is mixed only acoustically (in the air). The two domains are identical in many respects. Two identically amplified, correlated signals sum to just over +6.02 dBSPL, for example (not +3). This is why we say that the electrical signal is an "analog" to the acoustic waves... | Geoff Emerick de Fake wrote on Fri, 12 February 2010 06:27 |
Sensitive is the word... I suggest you get some info on Zwicker/Stevens experiments, that are mostly related to the masking effect and its consequences on intelligibility. Brains is a strange machine...
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What I mean by "sensitive" is that some boosts or cuts, rather than others, seem to create a phase shift that is advantageous. I am curious to see how only 1/4 or 1/2 a dB, which is within the frequency variance of the loudspeakers, let alone the room, is going to sound so very "dialed in" as it can often do... I am dubious as to how this is going to relate to hearing thresholds, or intelligibility, loudness metering, or the like. Thanks for your input, nevertheless. Andrew
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« Reply #34 on: February 12, 2010, 11:15:08 PM »
| Andrew Hamilton wrote on Fri, 12 February 2010 21:32 |
[...electrically, rather than one which is mixed only acoustically (in the air). The two domains are identical in many respects. Two identically amplified, correlated signals sum to just over +6.02 dBSPL, for example (not +3).
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How do two correlated signals acoustically sum to such a uniformity in any thing but maybe an anechoic chamber?
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« Reply #35 on: February 13, 2010, 12:33:34 AM »
| Andrew Hamilton wrote on Fri, 12 February 2010 22:14 |
| zmix wrote on Fri, 12 February 2010 01:52 |
Are you saying that the article you linked above (here) is somehow related to your assertion that phase shift has an "unmasking" effect?
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Are you saying that it doesn't?
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I was merely asking if you thought that that article was relevant to your claim that phase shift can cause 'unmasking'. Now, since you have asked, I will state that the article has nothing to do with phase shift. It is an examination of the unmasking effect of horizontal displacement in the stereo field between a sound of interest and a noise which limits it's intelligibility. I did note that this article was near the top of the search results when Googling "Phase Shift" and "unmasking". What Google means by "Sort by relevance" often isn't.... | Andrew Hamilton wrote |
Bob Katz has described the phase shift of the affected group as creating a different depth of field for the relevant instruments. This seems rather consistent with physically relocating the masker...
Andrew
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Are you saying here that phase shift is able to relocate a 'masker'? How? What is a 'masker'?
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« Reply #36 on: February 13, 2010, 06:54:32 AM »
| minister wrote on Fri, 12 February 2010 22:15 |
| Andrew Hamilton wrote on Fri, 12 February 2010 21:32 |
[...electrically, rather than one which is mixed only acoustically (in the air). The two domains are identical in many respects. Two identically amplified, correlated signals sum to just over +6.02 dBSPL, for example (not +3).
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How do two correlated signals acoustically sum to such a uniformity in any thing but maybe an anechoic chamber?
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Although I don't agree at all with andrew about the audibility of temporal displacement, I agree with the fact that two acoustic signals may combine at +6.02dB, even in a non-anechoic environment, provided the acoustic paths are strictly identical.
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« Reply #37 on: February 14, 2010, 08:03:59 AM »
| zmix wrote on Sat, 13 February 2010 00:33 |
I was merely asking if you thought that that article was relevant to your claim that phase shift can cause 'unmasking'.
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Yes. It was not intended as a joke. | zmix wrote on Sat, 13 February 2010 00:33 |
Now, since you have asked, I will state that the article has nothing to do with phase shift.
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Not explicitly; but, if the description of group delay as introduced by an eq is indeed similar to the depth of field of a target bandwidth within a given soundstage, moving closer, or farther away from the listener, then the horizontal variance of the masker, with respect to the masked, in the experiment cited, actually does seem to behave like the phase shift result of a pushing forward or backward with respect to the listener. With most waves, distance takes time. (I have actually heard that gravity waves propagate instantaneously between two objects, however...) This is why the passive time coherent speakers have recessed tweeters and mids (which are less so, but still recessed, compared to the woofers, yes?). Not only does a horizontal displacement, like all displacements, affect the distance between a sound source and the listener, and thereby introduce a time delay (i.e., phase shift) but also, from the listener's perspective, a horizontal displacement of a sound source (along the x axis, say,) forcibly includes a displacement, as well, on the Z axis (that of the "depth" of the soundstage). A straight line is not in this case the shortest distance between two points (which are on a soundstage's sphere of emenance). This is because unless the source which moves horizontally also moves forward, by a precise amount, then it has moved backwards, away from the listener (and a slight delay, by the speed of sound x distance is created)! This is why there is often a pan rule (e.g., Yamaha O2R's CW pan = +3 dB). | zmix wrote on Sat, 13 February 2010 00:33 |
...I did note that this article was near the top of the search results when Googling "Phase Shift" and "unmasking". What Google means by "Sort by relevance" often isn't....
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...isn't relevant? In this particular case, I'd have to say, "...or _is_ it?" And, for what it's worth, I used MetaCrawler, which is not as good, so I actually had to dig a while for that link. (O: Cheers, Andrew
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« Reply #38 on: February 14, 2010, 06:13:13 PM »
| Andrew Hamilton wrote on Sun, 14 February 2010 05:03 |
Not explicitly; but, if the description of group delay as introduced by an eq is indeed similar to the depth of field of a target bandwidth within a given soundstage, moving closer, or farther away from the listener, then the horizontal variance of the masker, with respect to the masked, in the experiment cited, actually does seem to behave like the phase shift result of a pushing forward or backward with respect to the listener. With most waves, distance takes time.
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Man, this is hard to understand. If you are saying that frequency-dependent phase shift causes some frequencies to be delayed relative to others then, yes. Do the frequencies that are delayed appear to move back in the image then, I don't think so. Or maybe you mean something else entirely. | Quote: |
(I have actually heard that gravity waves propagate instantaneously between two objects, however...)
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I believe the most recent understanding is that gravity propagates at the speed of light. | Quote: |
This is why the passive time coherent speakers have recessed tweeters and mids (which are less so, but still recessed, compared to the woofers, yes?).
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The voice coils are lined up in the same vertical plane. | Quote: |
Not only does a horizontal displacement, like all displacements, affect the distance between a sound source and the listener, and thereby introduce a time delay (i.e., phase shift) but also, from the listener's perspective, a horizontal displacement of a sound source (along the x axis, say,) forcibly includes a displacement, as well, on the Z axis (that of the "depth" of the soundstage). A straight line is not in this case the shortest distance between two points (which are on a soundstage's sphere of emenance). This is because unless the source which moves horizontally also moves forward, by a precise amount, then it has moved backwards, away from the listener (and a slight delay, by the speed of sound x distance is created)! This is why there is often a pan rule (e.g., Yamaha O2R's CW pan = +3 dB).
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Man, this is hard to understand. So, lets try this: Is your claim that equalization that has phase-shift moves the apparent position of instruments -- not due to amplitude change -- but from the frequency dependent phase? DC
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« Reply #39 on: February 15, 2010, 03:53:32 AM »
| dcollins wrote on Sun, 14 February 2010 18:13 |
| Andrew Hamilton wrote on Sun, 14 February 2010 05:03 |
With most waves, distance takes time.
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If you are saying that frequency-dependent phase shift causes some frequencies to be delayed relative to others then, yes. Do the frequencies that are delayed appear to move back in the image then, I don't think so.
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Well, what would be the acoustic corollary to a part of a mix being eq'd, resulting in the phase shift of some area of the spectrum (both within, and beyond, that which is boosted or cut by the cf/Q/gain adjustment)? I think it would mean that some of the signal would move forward or backward in time with respect to the unaffected areas and part of that would sound also louder, or quieter, due to applied gain and un-/masking (that is caused by both the applied gain and the concurrent group delay). The listener is able to assign any imaginable amplitude at the source, so only the timing with respect to the other parts of the signal (other instruments and partials that are possibly not delayed with the affected group) is giving us a sound-stage imaginary-image, plus the idea of synchronization of players and the abstract freewheeling tempo, of course (the temporal backdrop of the performance). A guitar note that was meant to fall on the downbeat, but is, nevertheless heard as lagging the downbeat by an arbitrary number of milliseconds passes a few automatic computations by the listening robot to be properly interpreted within the music. Either the note which is heard to be late was played at the same location within the soundstage as those notes on the guitar which were played "on time," but was merely played late, or, possibly (if not probably) that note _was_ played "on time," as well, but the guitarist was instantaneously scooted back (or his amp or PA was, if it was an electric guitar), just in time to make the note late... And if the level was not heard to be less loud than it would have been had the source of the guitar note _not_ moved, then did the guitarist not play that note both further back from the listener _and_ louder than normal? This explains why non-psychic pattern recognition is still not much better than Shakey. | dcollins wrote on Sun, 14 February 2010 18:13 |
| Andrew Hamilton wrote on Sun, 14 February 2010 05:03 |
(I have actually heard that gravity waves propagate instantaneously between two objects, however...)
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I believe the most recent understanding is that gravity propagates at the speed of light.
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Are you certain, man? If it goes no faster than C, then there would be no point using gravity motors to power space craft. ); According to the highly respected Bob Lazar, as well as the entity Bashar (from Essessani), the gravity wave is focused on the distant destination and this propagates instantaneously. The local "turntable" is faded down and the distant one is faded up, just like a DJ would do at a Rave. I know I'm not exactly preaching to the choir when I talk about space travel. (; But I'm sure you know some nice hetero dyning establishments in the So Cal area, don't you? (; (j/k) | dcollins wrote on Sun, 14 February 2010 18:13 |
| Andrew Hamilton wrote on Sun, 14 February 2010 05:03 |
This is why the passive time coherent speakers have recessed tweeters and mids (which are less so, but still recessed, compared to the woofers, yes?).
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The voice coils are lined up in the same vertical plane.
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That's a neat coincidence considering that the cones are not on the same Z axis - y-axis linearity, notwithstanding. | Quote: |
...Is your claim that equalization that has phase-shift moves the apparent position of instruments -- not due to amplitude change -- but from the frequency dependent phase?
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Well, again, not the whole instrument... But the affected parts of the instrument - perhaps even entire notes - though not likely all partials of all notes, even if all fundamentals were skewed somewhat in gain and timing. That could be what helps us decide if the guitar note is late due to the performing or the distance. I think I'm saying you get an amplitude change from both aspects (f and
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« Reply #40 on: February 15, 2010, 01:12:15 PM »
| Andrew Hamilton wrote on Mon, 15 February 2010 03:53 |
...
Well, what would be the acoustic corollary to a part of a mix being eq'd, resulting in the phase shift of some area of the spectrum (both within, and beyond, that which is boosted or cut by the cf/Q/gain adjustment)? I think it would mean that some of the signal would move forward or backward in time with respect to the unaffected areas...
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Andrew, you should simply work this out. Do the math. How much phase shift, and at what frequency? Once you know this you will have a basis to calculate the time delay. | Andrew Hamilton wrote on Mon, 15 February 2010 03:53 |
... and part of that would sound also louder, or quieter, due to applied gain and un-/masking (that is caused by both the applied gain and the concurrent group delay).
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What are you saying here, exactly.? For starters, define "masking". Secondly, show us how you determined the relationship between filter gain and group delay. | Andrew Hamilton wrote on Mon, 15 February 2010 03:53 |
The listener is able to assign any imaginable amplitude at the source, so only the timing with respect to the other parts of the signal (other instruments and partials that are possibly not delayed with the affected group) is giving us a sound-stage imaginary-image, plus the idea of synchronization of players and the abstract freewheeling tempo, of course (the temporal backdrop of the performance).
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(italics added for emphasis) Andrew, I have read through volumes of studies into soundstage and localization and never encountered any research which indicates that group delay defines the soundstage. What makes you state that this is so? | Andrew Hamilton wrote on Mon, 15 February 2010 03:53 |
A guitar note that was meant to fall on the downbeat, but is, nevertheless heard as lagging the downbeat by an arbitrary number of milliseconds passes a few automatic computations by the listening robot to be properly interpreted within the music. Either the note which is heard to be late was played at the same location within the soundstage as those notes on the guitar which were played "on time," but was merely played late, or, possibly (if not probably) that note _was_ played "on time," as well, but the guitarist was instantaneously scooted back (or his amp or PA was, if it was an electric guitar), just in time to make the note late... And if the level was not heard to be less loud than it would have been had the source of the guitar note _not_ moved, then did the guitarist not play that note both further back from the listener _and_ louder than normal? This explains why non-psychic pattern recognition is still not much better than Shakey.
Andrew
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Another possibility that the listener may conclude upon hearing a note NOT on a downbeat is that the music has a particular 'feel' or 'groove'...
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« Reply #41 on: February 16, 2010, 08:36:27 PM »
| Geoff Emerick de Fake wrote on Sat, 13 February 2010 05:54 |
| minister wrote on Fri, 12 February 2010 22:15 |
| Andrew Hamilton wrote on Fri, 12 February 2010 21:32 |
[...electrically, rather than one which is mixed only acoustically (in the air). The two domains are identical in many respects. Two identically amplified, correlated signals sum to just over +6.02 dBSPL, for example (not +3).
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How do two correlated signals acoustically sum to such a uniformity in any thing but maybe an anechoic chamber?
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Although I don't agree at all with andrew about the audibility of temporal displacement, I agree with the fact that two acoustic signals may combine at +6.02dB, even in a non-anechoic environment, provided the acoustic paths are strictly identical.
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So, in other words, you are saying that I could go into an average room, or even an above average mixing or mastering room, play a 1k tone or Pink noise out of the Left speaker, pull out an SPL, or even better an RTA and take a reading. Then put the same signal through the Right Speaker and my SPL meter would instantly read 6.02dB louder? Out of the millions of tiny variables that are in any given room, even if we went to great pains to try to make it uniform, that the radiating sound and all its energy would sum perfectly in a decent room? In theory, I can understand the idea. In practice, is there such a room?
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« Reply #42 on: February 16, 2010, 08:52:50 PM »
| minister wrote on Tue, 16 February 2010 19:36 |
In theory, I can understand the idea. In practice, is there such a room?
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Glenn Meadows said mono would sum +6dB in his Hidley room, and he's not one to joke about that sort of thing, but it always sounded like a stretch. Anything less and it ain't gonna happen. GR
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« Reply #43 on: February 16, 2010, 08:59:05 PM »
| Greg Reierson wrote on Tue, 16 February 2010 17:52 |
| minister wrote on Tue, 16 February 2010 19:36 |
In theory, I can understand the idea. In practice, is there such a room?
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Glenn Meadows said mono would sum +6dB in his Hidley room, and he's not one to joke about that sort of thing, but it always sounded like a stretch. Anything less and it ain't gonna happen.
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It means 100% of the energy is combined. I can see that in a wire or summing buss, but it's pretty impressive in air in a real acoustic space. What does that JohnJohn Kwankwan guy make of this? DC
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« Reply #44 on: February 16, 2010, 08:59:31 PM »
| Greg Reierson wrote on Tue, 16 February 2010 20:52 |
| minister wrote on Tue, 16 February 2010 19:36 |
In theory, I can understand the idea. In practice, is there such a room?
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Glenn Meadows said mono would sum +6dB in his Hidley room, and he's not one to joke about that sort of thing, but it always sounded like a stretch. Anything less and it ain't gonna happen.
GR
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Actually, he said just over +5.9 dB, at Monsterphonix... He also explained that this is why the old SSL's had a pan rule of -4.5 dB (at 12:00), rather than the measly -3 dB that most consoles use. It was believed that rooms with SSL budgets would be, acoustically, closer to the ideal. A mastering room should sum _correlated_ tones at over +5 dB, iuam. Mine does, and it aint even an Augsperger, let alone a Hidley. Andrew
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