Ah... I think I know what you're talking about now. Some of the strings on the lyre are quieter/harder to pluck at that volume, depending, so when it gets loud, that aspect of the instrument stands out. Compression already improved that situation, but it didn't improve it as ideally as it could have. Since I designed the instrument myself, one thing I've had to do is figure out the proper string gauges, and it ends up being more finnicky than expected.
Also... the top strings are gut, which I think amplifies that effect of needing accurate string gauge to get proper tension.
