DSP options
These options change the way things sound. How quickly changes are heard depends on the buffer size set in the Output options. If a crossfading track change transition has been set in the Playback options, that will further increase buffering and latency.
Right-clicking on a slider (except for reverb) will reset it to the default position.
Amplification slider
This is different to the volume slider. The volume slider controls the level of the sound card output, the amplification slider controls the level of the actual decoding. The higher the amplification, the greater the dynamic range of the decoding output, but if it is too high clipping may occur resulting in distortion of the sound.Reset on new track
This resets the amp level to 0 dB (or Replaygain value) when a track is loaded, and optionally when a new subsong is started too.Auto-amp
This causes the amplification level to be automatically reduced whenever clipping occurs. With fade-in enabled, it will fade-in new tracks until they clip, then it'll behave the same as normal. Dynamic mode continues to increase and decrease the amplification level throughout playback.Replaygain
When a track has Replaygain information, XMPlay can use it for the default amp level. When a track doesn't have the preferred value but does have the other (eg. "Album" is chosen but only "Track" is available), it will be used instead. When Replaygain is active, auto-amp is automatically disabled until the amplification slider is moved away from the Replaygain level.Pre-amp
This is added to the Replaygain level.Limit according to peak level
When enabled, this will limit the Replaygain level according to the peak sample level (if available), so that it does not clip. If there is other DSP enabled (EQ/reverb/etc), they could change the level and cause clipping despite this limiting. The "Pre-amp" option could be used to compensate.The availability of Replaygain information is shown in the "General" info window.