2rncekel
The right attitude i.m.o. : using as less channels as possible, only expand if things have to be simultaneous.
I can't judge if it could have been 4 chans, therefore I should see the trackerfile itself.
Of course these sounds are extremely difficult to loop, because the character of the sound changes during the note.
So just repeating the sample would often lead to 'jumps' in the sound. There are some ways though to make this more smoothly, especially with samples of strings, choirs, etc (enquires heavy zooming in on the waveforms) :
a - Make sure first and last sample-points of the instrument are at zero level. (if they are not, apply fades in and out on a very small selection of points at start and end. Some millisecs will not affect the hearing of it.)
b - Analyze the first two and the last two samples of the sound. If the 2nd and the prelast points are different in polarity (so above or under the zero-line), it's probably ok to loop directly. If their polarity is the same you can imagine a 'strange' jump in the waveform, because normally it swings from positive to negative and vice versa. If so :
c - Select the whole waveform and reverse the phase 180 degrees, in other words : upside down. Then paste this after the original, to create a new waveform. Having a double length of course. But with the transition from end-byte to a new start in the loop in a normal way, from plus through zero to minus or vv.
d - If still not satisfied with it, one could try to select the new, double waveform, reverse it in time, so horizontal, and paste it after the double waveform. So the duration of the sound is twice as long. But present fluctuations in sound during the single instrument-sample will probably have a more 'natural' action while looping.
Never worked with the iti-format, so I will see.