Request for improvement : RTA distorsion window in sine generation


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Thread Starter
Sep 28, 2020
My AV System  
Main Amp
In sine generation, the RTA distortion window (Show distortion) gives the noise N as a ratio to the total input power (N/Total input power) if the Y axis units are dBc or as an absolute figure (N) for other Y axis settings.
According REW, N = noise (noise floor or level without signal) + non-harmonic distortion

In both cases, the information is called N but the unit (dB or dBFS…) allows identification.

I would find it interesting to have these 2 information (N and N/Total input power) simultaneously in the same distortion window.
This information N/Total input power does not represent the signal-to-noise ratio (SNR) because N included non-harmonic distortion but is close to it (the sign must also be reversed).
Some audio softwares do not hesitate to name this quantity SNR but it is an abuse.

In this case of simultaneous display, N in the case [N/Total input power] could possibly be named differently to avoid any confusion (TN for example since it is a rate).

Remember that the Signal to Noise Ratio(SNR) can be obtained by 2 recognized methods:
- [signal level (signal present)] / [signal level (signal not present)] for devices without ADC/DAC
- AES17-2015 standard mainly for ADC/DAC based devices
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