in my s950 ive mainly sampled in the highest bandwidth, 19200khz i believe... i have two with memory expanded fully so i havent had much of a problem with RAM/sampling time.... you can always resample later at half bandwidth if needed, but i usually just stay at full bandwidth but then apply some filtering... ive come to like using the filter alot, even on sounds i dont want to filter too much, i apply just a bit of it for a bit of character... if i dont want to change the sample too much i will apply the filter just to the point of being audibly noticable, that is, use the filter but not enough to do much... i dont know if this makes any difference really, but i seem to think that it sounds a lil better this way...
but, try this...
take a sample that you have sampled at full bandwidth, then resample at half bandwidth, and keep repeating the resample at half bandwidth command repeatedly... you will come upon a funny little message to let you know that you have resampled enough already!....
just a little weird thing that i stumbled upon...
