Just as a side note, spectrogram are not in any way indicative of compression quality.
Its interesting that you didn't see any differences between flac and opus, as opus has a hard 20 kHz low-pass filter and is 48kHz-only.
Its interesting that you didn't see any differences between flac and opus, as opus has a hard 20 kHz low-pass filter and is 48kHz-only.
I did not liked degradation at 140-128kb/s and noise above 16kHz and some artifacts 10-16khz that is clearly visible and much more impactful.
Here is spectrograms https://disk.yandex.com/d/PvQGSS2xBu7ucQ