Article: Understanding Digital Audio Measurements

[Curryblue]

Nobody is saying you will enjoy listening to it more. It's just technical measurement of distortion.

Isn't it fair to say that technical measurements of distortion have some relevance to how we enjoy listening?
Can't I say that distortion has some connection to the enjoyment of listening — at least in some cases, if not many? Please note that I'm referring to enjoyment in a 'normal' context, not in a philosophical sense.

 

[ahofer]

Isn't it fair to say that technical measurements of distortion have some relevance to how we enjoy listening?
Can't I say that distortion has some connection to the enjoyment of listening — at least in some cases, if not many? Please note that I'm referring to enjoyment in a 'normal' context, not in a philosophical sense.

Not sure where you are drawing the normal/philosophical line. It is certainly true that many of us get some satisfaction from owning equipment that is closer to the theoretical ideal, even if we couldn’t distinguish it from inferior kit in a blind test.

 

[Curryblue]

Not sure where you are drawing the normal/philosophical line. It is certainly true that many of us get some satisfaction from owning equipment that is closer to the theoretical ideal, even if we couldn’t distinguish it from inferior kit in a blind test.

I understand ( from your first reply also) that two "transparent" DACs may be indistinguishable in blind tests but maybe not all of them ( them: all dacs from Poor to Excellent) ... . If so, why prepare SINAD charts or measurement comparisons at all?

 

[ahofer]

I understand ( from your first reply also) that two "transparent" DACs may be indistinguishable in blind tests but maybe not all of them ( them: all dacs from Poor to Excellent) ... . If so, why prepare SINAD charts or measurement comparisons at all?

Asked and answered? Barometer of engineering quality.

 

[krabapple]

Isn't it fair to say that technical measurements of distortion have some relevance to how we enjoy listening?

Hearing isn't infinitely sensitive. We can measure levels of distortion than we can't hear.

Can't I say that distortion has some connection to the enjoyment of listening — at least in some cases, if not many?

Of course. No one is saying otherwise.

 

[VientoB]

Isn't it fair to say that technical measurements of distortion have some relevance to how we enjoy listening?
Can't I say that distortion has some connection to the enjoyment of listening — at least in some cases, if not many? Please note that I'm referring to enjoyment in a 'normal' context, not in a philosophical sense.

No because if the distortion is below the hearing threshold it's not going to be audible anyway.

 

[Sal1950]

Isn't it fair to say that technical measurements of distortion have some relevance to how we enjoy listening?
Can't I say that distortion has some connection to the enjoyment of listening — at least in some cases, if not many? Please note that I'm referring to enjoyment in a 'normal' context, not in a philosophical sense.

I believe that's fair enough. If distortion is high enough to be audible, maybe even slightly under the easily audible, it could spoil your enjoyment of the listening experience on both the conscious and unconscious level.

 

[VientoB]

I believe that's fair enough. If distortion is high enough to be audible, maybe even slightly under the easily audible, it could spoil your enjoyment of the listening experience on both the conscious and unconscious level.

Only if you allow it to.

 

[Sal1950]

Only if you allow it to.

Very true, way back in the days of my yoots, there were times I was listenin to my car radio from the back seat, it makin maybe 25% THD with it's vibratory power supply buzzin away, but yet havin the most wonderful listenin experiences of my young life

 

[Ken1951]

Very true, way back in the days of my yoots, there were times I was listenin to my car radio from the back seat, it makin maybe 25% THD with it's vibratory power supply buzzin away, but yet havin the most wonderful listenin experiences of my young life

Very OT, but I would love to know the distortion of the AM/FM radio with Reverb(!) in my daddy's 65 Pontiac Grand Prix. Loved driving it with the windows down and the radio on with reverb! I imagine that it would be found in another zip-code of our host's DAC chart!

 

[Vlad Soare]

In the intermodulation distorsion test, what's the y-axis measured in? I see it's dB, but I don't know what 'SMPTE/DIN ratio' means.

I take it the x-axis represents the amplitude of the input signals in dBFS. So, when the input signals are -60 dBFS, the green and purple curves show a noise level of approximately -44 dB. But what kind of decibels are these? I guess they can't be dBFS, because that would mean that the noise would be higher than the input signals, which obviously can't be right.
Sorry if this is a silly question. I'm still learning (and still have a long way to go).

 

[MAB]

In the intermodulation distorsion test, what's the y-axis measured in? I see it's dB, but I don't know what 'SMPTE/DIN ratio' means.

View attachment 483062

I take it the x-axis represents the amplitude of the input signals in dBFS. So, when the input signals are -60 dBFS, the green and purple curves show a noise level of approximately -44 dB. But what kind of decibels are these? I guess they can't be dBFS, because that would mean that the noise would be higher than the input signals, which obviously can't be right.
Sorry if this is a silly question. I'm still learning (and still have a long way to go).

More about IMD

Learn about Intermodulation Distortion (IMD), its measurement methods like SMPTE, MOD, DFD, and CCIF and how they impact audio devices and signal quality.

www.ap.com

The stimulus is a strong low-frequency interfering signal (f1) combined with a weaker high frequency signal of interest (f2). f1 is usually 60 Hz and f2 is usually 7 kHz, at a ratio of f1_f2=4:1. The stimulus signal is the sum of the two sine waves. In a distorting DUT, this stimulus results in an AM (amplitude modulated) waveform, with f2 as the “carrier” and f1 as the modulation.

 

[voodooless]

Sorry if this is a silly question

It’s not a silly question, it’s a good one. And you almost got it. It’s the ratio between signal and IMD products, not noise.

 

[Sal1950]

Very OT, but I would love to know the distortion of the AM/FM radio with Reverb(!) in my daddy's 65 Pontiac Grand Prix. Loved driving it with the windows down and the radio on with reverb! I imagine that it would be found in another zip-code of our host's DAC chart!

Wow, that's a very high end system for 1968 !
I owned a 1972 Pontiac Grand Prix with the 455 SJ engine package. No drag racer for sure but tons of torque and it just loved highway runs over 100+ MPH. To be honest it is one of my favorite all time cars until it was totaled at 3am while parked in front of my house. Now that was a CAR
What a shame and for what, to be replaced by some POS Hyundai

 

[Ken1951]

Wow, that's a very high end system for 1968 !
I owned a 1972 Pontiac Grand Prix with the 455 SJ engine package. No drag racer for sure but tons of torque and it just loved highway runs over 100+ MPH. To be honest it is one of my favorite all time cars until it was totaled at 3am while parked in front of my house. Now that was a CAR
What a shame and for what, to be replaced by some POS Hyundai

Daddy next car after the 65 GP was a 69 GP. Dark blue with a white top. Truly beautiful car.

 

[Vlad Soare]

It’s not a silly question, it’s a good one. And you almost got it. It’s the ratio between signal and IMD products, not noise.

Ah, so it's dB relative to the input signal. Indeed, it makes sense. I should have thought of that.
Thanks.

Yeah, I said 'noise' because at that low level IMD is dominated by noise, but you're right, it's IMD I meant.

 

[voodooless]

Yeah, I said 'noise' because at that low level IMD is dominated by noise, but you're right, it's IMD I meant.

No, it’s not noise. It’s actual tones. See this excellent post:

Harmonic and Intermodulation Distortion

This post provides a quick comparison of how a distortion percentage relates to dynamic range in dB. That is, if an amplifier has 1% distortion, what does that mean? How soft (or loud) is 1%? Figure 1 shows a 1 kHz voltage signal with 1% second harmonic distortion (HD2) added. The spectral...

www.audiosciencereview.com