the VOLUME vs DISTORTION problem.
(if this is TOO LONG, just read the BOLD parts)
as I work on an update to eyeland (shameless plug), i'm finding it's really tough to get close to the loudness of music and sound heard in games made with the SDK and other non-pulp environments without it distorting/clipping. i assume that with those games you can bring in externally-made mp3 files or some such format and those files can be processed with audio volume compression. (compression helps to to tamp down the loud spikes and bring up the low valleys, making it possible to raise the overall volume of your music without clipping or distortion.)
anyway, as far as i can tell there is no audio compression applied to music made in Pulp. It's a lovely, VERY basic editor — just simple sound waves piling up on each other and because of this, your music is going to either sound a bit quiet, or distorted.
knowing some things about the nature of these sound waves will help you get a little extra volume while avoiding too much unpleasant distortion.
▷ the sine wave is a curved shape and has a very smooth sounding tone, so when it distorts, it's really noticeable. it sounds quite different...
▷ the triangle wave is a little bit brighter/ringy-er because the shape isn't curved, it's straight lines angled UP and angled DOWN, but it's a smooth tone so when it distorts it's also easy to tell - it's does not sound good.
the peaks and valleys of sine and triangle waves happen in the same place, so when same or harmonizing notes of a sine and a triangle wave play at the same time, all, or many of those peaks and valleys perfectly overlap - this causes those peaks and valleys to reinforce each other, driving the volume much closer to clipping/distortion.
▷ square and sawtooth waves have harsh shapes (instantaneous jumps/dips in the wave amplitude/height) that makes them "buzzy" in the way that they sound, so if they clip or distort a little bit, it's much less noticeable -- you can get away with more.
the peaks and valleys of square and sawtooth only slightly line-up with each other, and they do not line up with sine and triangle waves... (you see where this is going.)
▷ and noise is just that: stochastic chaos! it's pretty much impossible to make the noise wave distort any more than it already is.
OK - now we know that stuff, here are some things to keep an eye on.
▷ try not to have SINE and TRIANGLE waves creating harmonies or notes that play at the same time... instead, try SINE and SAWTOOTH -or- TRIANGLE and SAWTOOTH -or- TRIANGLE and SQUARE... not only do these combinations help prevent the perfect alignment/reinforcement of peaks and valleys, the inclusion of a "buzzy" wave sound (sawtooth or square) helps to "hide" slight distortions that might happen when the volume gets too loud when the notes combine.
▷ if you are getting clipping only on the very peaks, maybe try delaying the attack slightly of one of the tracks that has notes when the distortions happen (i've never done this, but it might help? )
OVERALL - try keeping your music from getting too dense. making sure there aren't too many notes at the same time piling up on each other will help. I went back to a few tracks and listened for problem areas and just took out a few notes here and there and it was hardly noticeable. sometimes i'd move the notes to create a sort of syncopation and wound up liking the edited track better.
if anyone else has any ideas on how to drive up the volume, but avoid distortion in Pulp, I AM ALL EARS!