Apparently, Cubase 8.5 downconverts audio files assigned to the metronome to mono, 16-bit, 44 kHz or maybe less. It sorta sounds like 8- or 12-bit to my ears.
Granted, it’s not the end of the world, but please understand that I put some effort into my custom metronome “click.” Similar to the popular UREI electronic metronome sound, it’s stereo, 24/96, and has a nice high-end that, when you put it all together, cuts through at modest volumes. Unfortunately, Cubase reduces it to monophonic mush, as if bitcrushed through an 80s sampler.
I forgot to mention that I seen Junkie XL in one of his videos saying he uses his metronome click from within Groove Agent, So im guessing he gets the metronome to audio file some other way then loads into Groove Agent which tempo syncs to project etc and just write in MIDI parts where you want the metronome ? thats what I gathered anyway.
So this suggestion might be very valid. Im no metronome expert though lol.