How eletrictifed is the live music? How loud? How much ambient noise, what is typical listening distance vs recorded, etc, etc.? In other words, there may be more perhaps many more salient variables involved in live and recorded music that affect learning than you have so far considered.
In other words, the question you raised may be too simplified for a meaningful answer, too many unknowns.
To the extent such things have been studied, it has been mostly by musicologists, who have been taking a turn away from theory and towards cognitive science in recent years.
Last edited:
George, Howie,
In my work it is sometimes useful to predistortion the signal. As mentioned there is no limit on compression but there is on rarefaction.
As the distortion starts at the third harmonic and atmospheric absorption increases with higher frequencies the distortion properly applied is below perceptable levels.
As a rule of thumb rarefaction limits SPL to mid 190s DBs. The sound pressure level at the compression driver diaphragm is 91.2 dB higher than the level delivered across the length of a US football field. As the desired peak SPL is around 112 dB that would require 203 dB or about 8 dB more than is possible on the rarefaction stroke.
So the solution is to use more compression drivers, larger diaphragms in the drivers, more limited bandwidth passbands with a multiway system or predistortion.
In simple terms much past highly compressed 102 dB levels at 200' requires a bit more attention.
BTY holding your ear next to the loudspeaker to check for buzzes and rattles is not recommended.
In my work it is sometimes useful to predistortion the signal. As mentioned there is no limit on compression but there is on rarefaction.
As the distortion starts at the third harmonic and atmospheric absorption increases with higher frequencies the distortion properly applied is below perceptable levels.
As a rule of thumb rarefaction limits SPL to mid 190s DBs. The sound pressure level at the compression driver diaphragm is 91.2 dB higher than the level delivered across the length of a US football field. As the desired peak SPL is around 112 dB that would require 203 dB or about 8 dB more than is possible on the rarefaction stroke.
So the solution is to use more compression drivers, larger diaphragms in the drivers, more limited bandwidth passbands with a multiway system or predistortion.
In simple terms much past highly compressed 102 dB levels at 200' requires a bit more attention.
BTY holding your ear next to the loudspeaker to check for buzzes and rattles is not recommended.
Last edited:
Near every record, now, is "produced".
Even live recordings are deeply worked in studio. No fidelity involved: They sound "better" than what we would had heard in the theater.
One could say that Pop music records are hyperrealistic paintings.
The same could well be true of your language and how some words might sound to a foreigner, how would you know?
Could we imagine compensating upstream the distortions, (based on the absolute phase dissymmetry), levels and frequencies depending, to reduce the effects due to compression of the air in the the horn's drivers ?
"Gas equation" is really not a proper term for the above expression. As I understand it, it reads "pressure X volume raised to the exponent 1.4 equals a constant". If my reading is correct, then in Thermodynamics it would be referred to as the equation of the isentropic state change of a perfect gas, with 1.4 being the isentropic exponent for biatomic gas molecules, or a mixture of such molecules, such as e.g. air. The constant at the RHS of the expression is a result of the system of units used, and if V represents the space occupied by a quantity of gas it would be of rather limited use.
However, I suspect that V stands for the specific volume, i.e. the volume divided by the gas mass (or a number of moles), which is the reciprocal of density. This would then be the form customarily used in Thermodynamics.
The constant exponent value used implies a certain gas model, i.e. the equation of state. The perfect gas assumption is the simplest one to use, and is adequate for air at the atmospheric conditions.
Regards,
Braca
I was thinking to a computer, analyzing the signal, and modifying the instant level of it, depending on the phase, level, and slope of the original signal according to a table. I suppose it is possible.
I'm not thinking specially about PA, but even home Hifi systems, horn based.
You know, like we compensate the photographic sensors and some defects of the lenses, like geometric distortions, colors errors, vignetting ...
I remember seeing a video in the 70s describing some tests they did on babies and their abilities to hear different sounds. That was with one native American dialect. The conclusion was that the brain locks into the required sounds by 18 months for the language used in its environment. I haven't seen any newer research than that, but certainly, although my son refuses to speak Hindi he has an ear for it.
I have seen other research that suggests the reaction to music is also learned in terms of the emotional responses it creates. So as an extension I don't see any reason why you couldn't in theory train a child to be able to pick up certain things that adults can't.
Unfortunately, although I have a suitable test subject I think SWMBO would been unhappy with me using youngest for research 🙂.
I have been wondering one thing. Some people do still consider vinyl to be superior to CD. Is it possible that they have very poor pitch sensitivity. One thing that it is very hard to get under control is pitch as you have various sources of error from the tuntable, more from record eccentricity and a huge gob from the fundamental cartridge/tonearm resonance, all of which FM the wanted signal. So for those who think vinyl is better do they love the 'phat sounds' or are they just highly insensitive to the pitch variations?
I suspect most who listen to other sources for a while will be very annoyed by the audible
pitch variation in most PUs, especially if they listen to much piano music.
OUCH! Simple question. VERY complicated answer/s. Anyway, I'll give it my best shot:
First off: The pitch stability thing. A number of years ago, one of my clients came to me with a conundrum. He loved vinyl, but his wife (a professional musician) hated listening to LPs, but quite like CDs. He didn't care much for CDs (it was the early 1980s). I quickly came to the conclusion that his wife was sensitive to pitch instability, so I located a Denon DP57L turntable to replace his Linn. The Denon has exceptional pitch stability. Result: Happy wife, happy life.
Now that's out of the way, things get pretty murky. I feel that a really good vinyl system, using a really fine transducer (the Dynavector 17D series is one of the best, if not the best available - FR >60kHz), playing THE BEST vinyl available (usually, those Sheffield Labs Direct to Disk recordings) sounds better than 16/44 digital. I am not alone in this opinion. Comparing ordinary recordings, 16/44 is usually superior. That said, one must first excuse the obvious limitations of vinyl, such as S/N etc.
There is another issue as well, often neglected by most observers. Like it or not, a vinyl system's sound can be easily altered by the owner. Change the VTA slightly, sound changes. Swap out the cartridge for another, the sound changes. Listen during cooler weather, the sound changes. And so on. Vinyl is a challenge for listeners and many like it that way. And, of course, therre is the whole issue that I liken to the Japanese tea ceremony. The Japanese tea ceremony is not strictly about tea. It is about the process. The process to play an LP is quite involved. The LP must be carefully extracted from it's sleeve. Examined for blemishes. Then placed on the turntable. It must then be cleaned (always). The tone arm carefully lowered and the volume adjusted for listening. At the end of one side, the process must be repeated.
Hipster Heaven.
And yet some insist vinyl is superior. I love playing vinyl, but I'm painfully aware of its limitations.
@ZB: Doesn't matter how stable the TT motor is there are still a multitude of sources of distortion that manifest as pitch instability. Luckily modern computers and clever people mean that it's a lot easier to locate them these days. You'll still never get close to CD on that parameter though. Or any to be brutally honest.
It is not, as the sonic difference between any master and its vinyl is obvious.
But it leaves room for the imagination, which the CD does not do, in its sharp objectivity.
I would suggest that a cartridge like the Dynavector 17DIII, mounted to a good arm (a Dynavector DV507 would be ideal), playing the best quality vinyl, will allow "sharp objectivity" to the recording. Don't forget: A square wave of more than 7kHz cannot be reproduced by any 16/44 digital system, whereas the 17DIII can easily reproduce square waves of more than 20kHz. Moreover, the vinyl system, itself, can capture those square waves. Whether this is audibly significant is subject to considerable conjecture.
Please note: I am VERY SPECIFIC about the cartridge, as the 17DIII is one of the few available that has been designed and built to be ruthlessly accurate.
Not aware of any test records with 20kHz square waves on, or even any cutting head that can cut them. Do you have any sources, or is this an extrapolation from the spec sheet for the cartridge?
I'm personally not a fan or the short cantilever concept as it seems to cause more problems than it solves. But like many things in vinyl there are plenty of people happy with it.
I'm personally not a fan or the short cantilever concept as it seems to cause more problems than it solves. But like many things in vinyl there are plenty of people happy with it.
I can't locate my CBS STR112 test LP, but I recall that it has 10kHz square waves recorded on it. Still far in excess of what any 16/44 digital system can manage. 10kHz square waves can be managed by even quite modest cartridges. And yes, I've used it over the years to test high end LP systems. It doesn't get a lot of use nowadays. And, as I'm sure you are aware, the waveform on the LP that corresponds to a square wave, appears as a triangle waveform. Something that can be relatively easily managed by a cutting head.
What problems? I've used cartridges like the Decca London, which has a VERY short cantilever and found the results to be stunningly good. The 17DIII is, arguably, the must accurate cartridge ever made. I accept that many listeners do not like accuracy.
Last edited:
i was not referring to a specific aspect of one cartridge, but a global process which I doubt (courtesy) that it can reproduce a square signal at 0dB from analog tape (distortion, signal noise ratio, bandwidth non linearity, pre/post echo etc.) to vinyl (bandwidth, distortion, noise surface, clics and scratches etc).
All the test disk I knew were made with direct cutting at 10KHz and -24dB.
And it is not very beautiful to look at.
Last edited:
CBS STR-112 is a 1kHz square wave, which CD can produce a lot more cleanly that vinyl. The decca, being a zero length cantilever horizontally is a special case and a very poor tracker! But loved by the brave.
I've never before seen the 17DIII described as the most accurate. I will do some digging.
I've never before seen the 17DIII described as the most accurate. I will do some digging.
Thanks for the clarification on the STR112. And yes, I know the Decca very well. It was always nice in some ways, but frustrating in others.
You may never see it mentioned as the most accurate, since many vinyl lovers are not, specifically, trying to achieve an accurate result. The figures for the 17DIII are impossible to refute. It is very accurate. Arguably, the most accurate cartridge ever made. It has two more features that make it stand out from the crowd:
* Every 17DIII sounds the same as every other 17DIII. This is a feat not managed by many high end cartridges.
* The 17DIII is far more resistant to temperature and ageing than almost any other cartridge, due to it's unique suspension system.
- Status
- Not open for further replies.