Are you still having trouble with other MAME BIOS files? Common companion files include neogeo.zip (for SNK games) and pgm.zip (for IGS games). Each has its own quirks, but the installation method is nearly identical to the QSound process described above.
Some MAME builds (especially libretro cores) have a bug where QSound HLE is emulated at 10% volume.
Why MAME separates HLE files from main ROM sets
) and why preserving the exact nuances of its 16-channel sample player is vital for cultural history. The Technical Breakthrough : Mention the importance of the MAME source code