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).