My bass guitar has 23% THD
Yes, and it's working perfectly as intended. The point of an audio playback system is to accurately and faithfully reproduce the "distortion" of your guitar without adding its own.
My bass guitar has 23% THD
Yes, and it's working perfectly as intended. The point of an audio playback system is to accurately and faithfully reproduce the "distortion" of your guitar without adding its own.
I see a lot of people equating the results from a limited DBT to that of a population survey. Some of the test methodology or data could apply, but I have yet to see ANY DBT report present data in statistical terms beyond the elementary school level.
It depends. On the one hand, you have “gear shoot-outs” and try-at-home ABX tests, many of which are not scientifically rigorous or contain enough data points.
On the other hand, though, psychoacoustics is a reasonably well-developed field. We have fairly extensive and convergent data on things like masking thresholds, equal loudness contours, etc etc. We have a detailed model of the functioning of the auditory system. There really aren’t that many mysteries left.
Psychoacoustics is reasonably developed in scientific circles, with medical science and acoustics being well developed fields in their own right. Corruption from outside the field (audiophiles, certain companies) is a big issue though. As a result, there are many doctors and acousticians who approach psychoacoustic with a great deal of skepticism.
I agree with your view, in fact I share it.
I've one question regarding IMD.
Since this particular distortion comes from the interaction of any two frequencies, and taking into account that any two frequencies will create many IM byproducts (though f1+f2 and f2-f1 will be main ones for their amplitude)...what does it mean in terms of overal quantity of IMD: total IM distortion?
I ask this because THD seems more limited to me in overall impact, it's each frequency creating harmonics, while with the IMD its each frequency * each other frequency (square relation!) which creates distortion.
Will this cause (in a realistic situation) that actual total IMD (TIMD?) would be much higher than THD? (IMO, taking into account IM measurements available, I don't see any other possibilty...).
What specific aspects of psychoacoustics are approached with sceptisism? Why?
The ability of humans to hear or perceive sound well into the ultrasonic range for one. Human testing and cadaver research over the past 50 years or so show this to be highly unlikely/unreliable.
Then there is the psychoacoustic mumbo jumbo that serves as the basis for hires music, which is touted by some music providers but pretty much debunked by science.
The ability of humans to hear or perceive sound well into the ultrasonic range for one.
Yes, and it's working perfectly as intended. The point of an audio playback system is to accurately and faithfully reproduce the "distortion" of your guitar without adding its own.
The ability of humans to hear or perceive sound well into the ultrasonic range for one.
I wasn't aware psychoacoustic science made such claim.
That's not psychoacoustics, it's marketing and quackery
What if Ray’s guitar SHOULD have 25% distortion? Then a distorted amp or dac may be just what the doctor ordered?
You should be aware that in the scenario when 3 or more tones are playing simultaneously IMD components become more and more complex/numerous. For that reason I don't think it is possible to express total IMD. What you typically see as IMD figure is two tone IMD but I don't remember seeing IMD "sweep" measurements over the entire frequency range. Not to mention that distance between 2 tones could be variable as well..
I rather liked the idea of SFDR which is subtly different than SINAD.Multitone measurements are popular in the RF world, as are NPR (noise-power ratio) measurements, but I have not seen them performed at audio either.
Most measurements I have seen jump from SNR to THD to SINAD. SINAD includes all non-signal "stuff" be it HD, IMD, power supply spurs, random noise, or what have you. When I was designing and testing my circuits I wrote a MATLAB program to calculate SNR, SINAD, THD, and IMD for single- and multi-tone (up to ten IIRC) measurements. Easy enough using something like that, and of course using the IEEE or some other scheme to choose the test frequency(ies) to prevent binning multiple products into a single bin.
I rather liked the idea of SFDR which is subtly different than SINAD.
Human testing and cadaver research over the past 50 years or so show this to be highly unlikely/unreliable.
I would hope cadavers would not shed light on any useful issues.