Very true.
When people grew up with the advent of microelectronics, "Moore's Law" became practically a mantra. When some of them got involved with audio there was often an attempt to apply this notion of "progress" to everything, including loudspeakers. And there was a lot of frustration expressed when these people were told that speakers were a pretty mature product, and that specific materials costs were not that elastic with volume. And, that as well, moving air was always going to take material and energy, even though one could suppose incremental progress would continue, as indeed it has.
This inconvenient truth used to spawn other management fantasies when someone would come along with something that purported to do away with old constraints, and by virtue of using some new technique be claimed to obsolete traditional designs in no time flat. The NXT panels and Elwood Norris's ultrasonic heterodyne stuff were among the offerings. There were also some rather naive power amp approaches, I won't enumerate them here but suffice it to say they have not taken the world by storm.
An issue not often dealt with at the hiend of audio is that manufacturers have to pay royalty/patent fees to numerous people/corporations in a single product. I have been told by asian mfr that the limiting cost of a product is often the fees added to the product cost and not parts costs. Even if parts and labor were free, it would still cost the consumer a good chunk of change because of all the fees attached to the product. In many hi-tech products the fees contribute more than the costs to build/assemble it. -RNM
The big growth in the future for audio will be that of understanding of the need for refinement, not major "advances". As said, the iPod generation, and many of the previous ones as well, are all about numbers getting bigger, more impressive, and that's just not going to do it in the area of music replay.
My fiddlings and experiments have demonstrated to me that the inherent quality in nearly all electronics, half reasonable and above, is quite adequate to produce spectacular results, if the right attitude and philosophy is brought to bear upon the exercise.
It's not "progress" that's needed, it's understanding where the weaknesses are, knowing that these are what are undermining the potential of what you have acquired or designed, and then carefully, precisely eliminating them, ie, the problems ...
It is really like debugging a piece of powerful, but flawed computer sofware ...
Frank
My fiddlings and experiments have demonstrated to me that the inherent quality in nearly all electronics, half reasonable and above, is quite adequate to produce spectacular results, if the right attitude and philosophy is brought to bear upon the exercise.
It's not "progress" that's needed, it's understanding where the weaknesses are, knowing that these are what are undermining the potential of what you have acquired or designed, and then carefully, precisely eliminating them, ie, the problems ...
It is really like debugging a piece of powerful, but flawed computer sofware ...
Frank
At a certain level of refinement the sound subjectively becomes very sensitive to the slightest disturbances in the environment, typically quite obviously electrical in nature. The measurement regime needs to be sensitive to those subtle variations, and I certainly don't what sort of measurement techniques, conventional in nature, that will precisely point to where the damage is being done to the sound in these situations. A reasonable guesstimate of a test with perhaps some value, is of a multitone, that comprises 2 elements: a set of frequencies which stresses the system overall electrically, say high level bass and midrange tones, and a second pair of low level, high frequency treble tones, selected so that they are completely unrelated harmonically to the "exercising" tones. Then, all the measurement focus is purely on what harmonics and IM interaction of those treble tones is spawned ...
Frank
Frank
Produced in high quantity things designed on computer and never breadboarded are very cheap, especially when they made as cut and paste from datasheet examples. Similarly, produced in high quantity copies of some known designs. But how much will cost say an unique headphone amp for unique headphones? A fortune. You never know how much time is needed to design something unique and exceptional. And it requires unique skills that are not cheap.
AFAIC, it's not the THD number that matters, but the spectrum makeup of the distortion. Tests have been done where staggering quantities of distortion are injected, in particular down at the bass end, and no-one's the wiser. One amp can have 100 times lower overall distortion than another, but it's particularly obnoxious distortion in character, and the ear has no trouble picking it up and saying it doesn't like it ...
Frank
fas42,
It sounds like we would have to have a weighting system for harmonic distortion based on where in the 20 to 20Khz frequency curve we are. You are saying that at the lower frequencies that the distortion is not as important if I am following you here. At what point would that change to being an acute level that even at low percentage that we would clearly notice harmonic distortion between at least two separate tones.
It sounds like we would have to have a weighting system for harmonic distortion based on where in the 20 to 20Khz frequency curve we are. You are saying that at the lower frequencies that the distortion is not as important if I am following you here. At what point would that change to being an acute level that even at low percentage that we would clearly notice harmonic distortion between at least two separate tones.
This was quite eye-opening, when it was first pointed out to me: Experimental Study : Distortion - Axiom Audio ...
Frank
Frank
The next time they need better speakers for such research. At least, woofers are needed much better.
researchers have determined that harmonics can be detected down to .05%. Masking from system distortion (speakers) prevented knowing the true lower limit of hearing ability to detect change due to harmonics. I dont recall the bass only data but it would be higher, of course. For the electronic evaluation of an amplifier we would use the threshold (<.05%) to be sure no one could hear the distortion we measure under any condition. I would go ten times lower as we dont actually know the 'real' distortion detection threshold is. In listening tests, a different critia could be applied; maybe a more loosely allowed level of distortion due to masking et al the issues that are Not electronic in nature.
JC has mentioned there are already proposed weightings to individual harmonics. I suggested doing same to FFT tests/plots... to weight the harmonics being shown. Several others have done work in this area in the past and show the amount of weighting to apply. -RNM
JC has mentioned there are already proposed weightings to individual harmonics. I suggested doing same to FFT tests/plots... to weight the harmonics being shown. Several others have done work in this area in the past and show the amount of weighting to apply. -RNM
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