This subject is covered in the Mixing Advice section of the reference manual.
If you are paying particularly close (and possibly unhealthy) attention to the output levels of samples playing from Sampler Channels, you may notice they are a few dB down on their level when played as Audio Clips in the Playlist. There are three reasons for this:
So together the default load state for a Channel Sampler can be about 8.2 dB lower than the samples actual recorded level. If you absolutely need a sample to render at its recorded level, load it as an Audio Clip by dropping your samples on the Playlist (these default to 100% volume, 0 dB). Finally, make sure the Master and Main volumes (described above) are set to 0 dB and don't forget the effect of note velocity on playback level.
Image-Line Support Team