furnace/doc/7-systems/qsound.md
2024-07-06 14:52:07 -05:00

1.3 KiB

Capcom QSound (DL-1425)

this chip was used in Capcom's CP System Dash, CP System II and ZN arcade PCBs.

it supports 16 PCM channels and uses the patented (now expired) QSound stereo expansion algorithm, as the name implies.

because the chip lacks sample interpolation, it is recommended that you try to play samples at around 24038Hz to avoid aliasing. this is especially important for e.g. cymbals.

the QSound chip also has a small echo buffer, somewhat similar to the SNES, although with a very basic (and non-adjustable) filter. it is however possible to adjust the feedback and length of the echo buffer (the initial values can be set in the "configure chip" option in the file menu or the chip manager).

there are also 3 ADPCM channels. ADPCM samples are fixed to 8012Hz.

effects

  • 10xx: set echo feedback level.
    • this effect will apply to all channels.
  • 11xx: set echo level.
  • 12xx: toggle QSound algorithm.
    • on by default.
  • 3xxx: set echo delay buffer length.

info

this chip uses the QSound instrument editor.

chip config

the following options are available in the Chip Manager window:

  • Echo delay: sets the length of the echo buffer.
  • Echo feedback: sets the amount of feedback on the echo.