1. When comparing lossy audios, remember to convert to WAV/W64 first with DRC disabled
  2. change volume levels to match each other
  3. dump it into your preferred analyzer such as RX10 etc, see if it has noise, if the audio is studio dithered, clipping, frequency… etc.
  4. listen to it yet again at similar sound levels, look for sharp noises such as clap, a school bell + also dialogue parts to differentiate the audio quality. Use foobar to determine the dynamic range and so on.