How to loop a stringsample ?

First, get the best bog-standard loop-point you can, ie. a loop-point that glitches as little as possible. Don't worry if it's not quite perfect. Place markers at the loop start and end points (your editor may do this for you once you've chosen the loop points). The loop start point should ideally be about 1/4 of the way into the sample, and the loop end point can be anywhere before the end (but before the strings stop playing!) so that between 1/2 and 3/4 of the entire sample lies inside the loop. The area of the sound before the loop is used to crossfade so while the figure of 1/4 is not critical it's important that these areas aren't too short or the crossfade might be easy to hear.

So... the simplest kind of crossfade uses a portion of the beginning of the sample and mixes it into the end of the looped part. We will need to define 4 main areas of the sample:
'A' is from the sample start to the loop start. Let's say it's (A) samples long.
'B' is the area inside the loop.
'C' is from the loop end to the sample end. In this kind of crossfade, area C can be deleted as you'll never hear it.
'X' is the crossfade source area, and is (X) samples long. X always ends at the loop start point, and (X) < (A) so that X doesn't contain the attack portion of the sound. When choosing X, you don't need to worry about zero-crossings.

Firstly, copy X into a new audio file and fade it in over its entire length. Next, select the part of area B of the string sample which ends at the loop end point, and is (X) samples long; place a marker at the start of this area so you can find it again, and fade it out. Now copy the faded-in version of X into the clipboard, place the cursor at the marker you just created (ie. at the beginning of the faded-out part of B), and perform a 'mix paste' so that the faded-in X is mixed equally with the faded out portion of B.

Then you go - one manual crossfade You might need to give it a few goes with different lengths of X or different loop positions to get the best results. There are also more complicated types of crossfade which take multiple crossfade sources from different areas of the sample and combine them with the original sound in various different ways; if you want a description of these I can scan in the page from my Ensoniq sampler manual where they are described I'm not going to try it here

Hope the above post doesn't cause your brain to explode... manual sample editing and crossfading can be fun - honest!

On 2007-03-24 13:32, Colin OOOD wrote:
Like I said, most samplers will do it for you Sometimes it's fun to get your hands dirty though.

On 2007-03-25 06:54, Seppa wrote:
when you refering to x samples, do you mean a lenght equal to the area X

X has to be part of the original sample right ? but which part ? it seems to me that x should be taken around the center of the loop section so its not too different from the end and the begining of the loop. I' m quite confused as you can see.