Keeping the discussion on track is a good thing. Don't apologize for that.janneman said:
My belief is that we will be easily able to measure ITD/IID for cables that far exceed human capability. If we test cables to 5uSec and .05 dB flatness, we certainly exceed what we can hear.
If those numbers are not exceeded under normal stereo conditions with full power into reactive load, then there just ain't anything there..
Those numbers were derived by setting an image fuzzyness upper limit, and determining the ITD and IID that bound that size. I believe I used a foot diameter.
I mention under full power with reactive load, as that is the most demanding part for the system. I fear that much time can be spent developing the correct test methodology to remove errors inherent in single ended drive systems with ground loops.
Cheers, John
fcserei said:
You are making it too complex.
The sibilance shift was entirely the fault of the speaker system. It was not matched w/r to driver efficiency or crossover tolerance. This looseness of system symmetry was far beyond the ability of the eq to make up for the soundstage destruction.
I was unable to compensate the fr variations with the eq without also introducing unwanted phase shifts.
This is the same thing my sound card does. Being mux'd, it has an inherent 11 uSec r-l delay, and the balance control is incapable of dragging the image back to center without altering the image presentation in some weird way, very unpleasant.
fcserei said:
From what I see, from all the research papers I have read, researchers I have conferred with, and responses such as yours, you are too eager to include the hugely complex way we actually hear and image.
That is, getting bogged down in the details. First, one must map what the real information is, what alters it, and then test how it is perceived.
Cheers, John
jneutron said:
OK then. Let's leave for the moment the 0.05dB flatness. I believe with all the other influences in a system even the very best setup is far from flat at 0.05dB, so that appears a non-issue as far as cables is concerned. It may be possible in very tightly controlled double blind tests to detect a 0.05dB difference in flatness, but I have NEVER seen it documented that indeed it is the case. You? At any rate, in 'normal' listening environments it is a non-issue.
Now to the 5uS (which I note is VERY much more tight than the 200uS numbers bandied around, but why not). Are there ANY physically realistic cables that cause a difference in delay between parts of the spectrum amounting to 5uSec?
Jan Didden
janneman said:
I am not sure that I could measure that with even the best equipment I have at my disposal. I agree that it is not worth persuing at this time..and I believe a more rational number needs to be worked out.
janneman said:
This is a question that I am very happy to hear.
This number is unfortunately very tight to encompass a wide range of angles and depths of image we wish to pretend is there. From what I know, measurement of this number by looking at the load (which is where we are actually concerned with as a result of IC changes), from my experience, is very very difficult because of the current slew rate, and the impedance which we are measuring across while it's magnetic field is collapsing or growing. Confound that with the ground loop issues which arise from the power draw, and amp internal construction, and it is indeed a formidable task.
I am quite confident that darn near any IC that is tested in isolation, will not do a single thing to the waveform that even approaches 5 uSec, probably not even nano level. But that is not the problem, the problem is in situ measurements. One where the amp is plugged into the same AC as the source, so that the ground loop can interact with various IC's to degrade via induction, the system response.
I believe, what I am basically saying, is that I don't think the materials used for the construction of an IC amount to much, but rather, it's shield resistance and shielding capability as defined by it's geometry. I do not believe in that grain boundary goop, nor that oxygen free goop, or speed of light stuff. (I am not that far removed from reality..maybe some, but not that much..)😀
Jan, a real pleasure. We will discuss more..
Thank you.
Cheers, John
jneutron said:
Not long it was thought that much of sound localization might be a direct result of interaction at early stages of the binaural system. Recent research suggests that the process is more distributed with peripheral centers of the brain sending information—about ILD, ITD, spectrum, and arrival order—to higher centers where the incoming data are evaluated for self-consistency and plausibility, and are probably compared with information obtained visually. Therefore, sound localization is not simple; it is a large mental computation.
When you offer inconsistent, not plausible set of data even if it satisfies ITD and ILD, it just won't make it.
What is thought of as a model for how we do what we do has certainly been changing over the years, hasn't it?fcserei said:
I have only researched back to Nordmark, 1976, to the present. I am amazed at the implementations of tests that have progressed through the years.. From jittered tones ala nordmark, through SAM (Leakey et al, 1958, Blauert, 1982, (sinusoidally amplitude modulated), to transposed waveforms (Van de Par and Kohlrausch, 1997).
The most amazing run was when pointer IID's were used with target ITD's (Schiano et al, 1986)😕 😕 . Using two sets of stimulation parameters which do not exist in nature...to decode the relationship between them and how we localize??? Holy mackeral...I'd have loved to be a referee for papers of that nature..
As you can see, I am not so much interested in developing a model of what goes on between the ears, just in what we perceive as a result of ITD AND IID shifting in the sources we are using to simulate "soundstage" as a result of system changes like IC's, PC's, and speaker cables. Human localization sensitivity and capability are not the end, they are the means..the only reason I am interested in this localization goop, is to get to the cables..I have been haunted for years with...what test parameters are required...Jan's exact question.
Cheers, John
Imaging and cables
Most cable phenomina are quite obvious in mono. In this case I mean literally using a single speaker as my friend and I have done while evaluating cables.
While differential group delays will certainly affect a mono signal, IMHO the whole sound stage or image placement pursuit is a diversion. Not that those issues are not important as well, but they do not seem to provide a direct link to whatever mechanism is taking place in the whole cable sound perception controversy.
In our interconnect cable tests we have discovered we can hear if a four conductor cable has the four conductors tightly spaced or spaced some distance apart. We first noticed that different insulating materials affected the sound even with the same conductor material. So then we experimented with different insulators and soon discovered that with identical material a tightly spaced cable sounded not as good as a cable made with a larger spread between the conductors. The spacing affects both basic capacitance and dielectric absorbtion. The basic capacitance is small enough that the effect caused by roll off happens well outside the "normal" range of human hearing. It would appear that we can hear dielectric absorbtion.
Most cable phenomina are quite obvious in mono. In this case I mean literally using a single speaker as my friend and I have done while evaluating cables.
While differential group delays will certainly affect a mono signal, IMHO the whole sound stage or image placement pursuit is a diversion. Not that those issues are not important as well, but they do not seem to provide a direct link to whatever mechanism is taking place in the whole cable sound perception controversy.
In our interconnect cable tests we have discovered we can hear if a four conductor cable has the four conductors tightly spaced or spaced some distance apart. We first noticed that different insulating materials affected the sound even with the same conductor material. So then we experimented with different insulators and soon discovered that with identical material a tightly spaced cable sounded not as good as a cable made with a larger spread between the conductors. The spacing affects both basic capacitance and dielectric absorbtion. The basic capacitance is small enough that the effect caused by roll off happens well outside the "normal" range of human hearing. It would appear that we can hear dielectric absorbtion.
hip boots, waders, or is it time for the raft?
have you considered moving one speaker back(forward) 3mm?
of course you then have the "intractable" problem of eq/balancing the ~(1997/2000)^2 amplitude diff (0.2 dB)
hermanv,
as for hearing da in speaker cable, you can take all of those RC branches in the da model and plug them into the wall outlet and you couldn't hear the result in an anechoic room with 100 dB/W speakers
jneutron said:
have you considered moving one speaker back(forward) 3mm?
of course you then have the "intractable" problem of eq/balancing the ~(1997/2000)^2 amplitude diff (0.2 dB)
hermanv,
as for hearing da in speaker cable, you can take all of those RC branches in the da model and plug them into the wall outlet and you couldn't hear the result in an anechoic room with 100 dB/W speakers
jneutron said:
John,
Fully agree, a cable connected to nothing isn't really sexy at all.
But let's go on. Suppose we have a source with 100 ohms Zout. We connect it withan IC of say 1 meter length to a power amp with Zin 10k ohms. Reasonable figures I believe.
Let us further assume that we listen to a voice or instrument spanning several octaves of tones, say from 500 Hz to 10 kHz. Agreeing to the 5 uSec as a minumum measure to hear audible localisation differences, what kind of cable would cause a difference in delay of 5 uSec between 500 Hz and 10 kHz?
I can't do that from the top of my head, but I would gamble that it would need to be a cable with a fractional microfahrad of capacitance, maybe in the order of 0.05 uF. THAT, I posit, IS unrealistic.
Jan Didden
So,
bring in NANOTECHNOLOGY into all this and then stakes will rise high.
nanotech fabricated cables might really affect the sound(or atleast test readings).but any big change(airy,roomy......),i doubt.
nanotech fabricated cables might really affect the sound(or atleast test readings).but any big change(airy,roomy......),i doubt.
sagarverma said:
What's a nanotech fabricated cable? You mean built by really short techies?😀
Jan Didden
Re: Imaging and cables
You did not change only one variable..spacing changes inductance and loop coupling..
You have not considered Faraday's law of induction.
John
hermanv said:
You did not change only one variable..spacing changes inductance and loop coupling..
You have not considered Faraday's law of induction.
John
Re: hip boots, waders, or is it time for the raft?
Ah, I apologize for the confusion..
The delay is heard in my headphones, not my speakers..I am sorry, I should have re-iterated that, as I did state it specifically I believe earlier in this thread, but perhaps not..
The 11 uS delay is readily heard in my headphones, and using the balance control does not fix the error. You are correct, if speakers, it would not be either apparant, or of any consequence, as it is the entire signal that was delayed.
Cheers, John
jcx said:
Ah, I apologize for the confusion..
The delay is heard in my headphones, not my speakers..I am sorry, I should have re-iterated that, as I did state it specifically I believe earlier in this thread, but perhaps not..
The 11 uS delay is readily heard in my headphones, and using the balance control does not fix the error. You are correct, if speakers, it would not be either apparant, or of any consequence, as it is the entire signal that was delayed.
Cheers, John
this nanotechnology thing is crazy.its aims of removing defects at microscopic levels r
IMAGINE,a cable with crystal level defects removed.effect or no effect?
IMAGINE,a cable with crystal level defects removed.effect or no effect?
- Status
- Not open for further replies.