Processor Thoughts

[Curvature]

SINAD of 100dB is just as inaudible as a SINAD of 118dB, it's a meaningless competition of which number is sexier.

This may come across as nitpicking. I've often seen this perspective repeated and I don't believe it's correct.

The main graph to reference is this one:

The message to get across is that SINAD is level dependent. Amir also posts some other graphs showing distortion for different frequencies. So level and spectrum. Level and spectrum. Like a mantra. Without that most of the single numbers people tend to discuss are meaningless, like you say.

 

[peng]

This may come across as nitpicking. I've often seen this perspective repeated and I don't believe it's correct.

The main graph to reference is this one:
View attachment 298091

The message to get across is that SINAD is level dependent. Amir also posts some other graphs showing distortion for different frequencies. So level and spectrum. Level and spectrum. Like a mantra. Without that most of the single numbers people tend to discuss are meaningless, like you say.

I would add that in most cases, if the single numbers, such as the example used (100 dB SINAD) could be meaningful enough that even without those curves, because in those cases, SINAD would most likely be above 80 dB at the extremes, that is very low output level such as below 300 mV and above 3 V. Other than that, single numbers of 80 dB vs 95 dB are, in many cases, don't mean a whole lot. In those cases, it may also depend a lot on the contribution of noise vs distortions that made up the single number.