A small test of how Sonic 1 sounds in: Gens-rr, Gens+GX under BizHawk, RetroArch and SDL frontend.
It's a bit interesting that while Gens-rr obviously has much high freqs, GPGXs differ from each other too! BizHawk and Retroarch sound nearly identically, but under SDL it has more low freqs and notably less high freqs. What can be a reason?
EDIT: Added console recording. Sounds also almost identical to BH and Retroarch, but seems a bit more clear to me. BTW, first drumbeat pitch on console is closer to Gens-rr.