For the sample I've tested, the other lossy encoders don't show the same behaviour. I did a quick comparison at ~64 kbit settings, and while LAME V9 goes up to an average of 80 kbit/s, the other encoders (Quicktime AAC, Nero AAC, aoTuV Vorbis, Opus 1.0.1RC3) all stay around 64 kbit/s. Plus, the two AAC encoders produce less noise than the two Opus encoders which use roundabout the double amount of bits.
Of course I know this is difficult terrain for lossy codecs, where distortion and noise can quite easily be found amidst the clean synth waves. Nevertheless, at this point this seems to be not only problematic in comparison to other kinds of sound, but also in comparison to other encoders.
Of course I know this is difficult terrain for lossy codecs, where distortion and noise can quite easily be found amidst the clean synth waves. Nevertheless, at this point this seems to be not only problematic in comparison to other kinds of sound, but also in comparison to other encoders.