To get back to the OP... if I read the manual correctly (love to be proved wrong, tho!) these audio multipads do NOT loop.
In other words, if you want a pad to go on for 16 bars (and it is a 2 bar phrase) you are going to have to manually ask for it every two bars. Either that, or import the audio into an audio editor, and copy/paste it so it becomes a 16 bar .wav file (and consequently, uses up your RAM faster - or does it read direct from USB?).
Not setting a simple 'loop flag' into the S950's .wav player (which is an old and perfectly standard code) turns what could be ground-breakingly useful feature to one far more suited to being a gimmick or a karaoke feature.
Yamaha's NEXT version of the PSR might be a pretty good arranger if Yamaha fix the audio functions, and change it from a karaoke playback machine into a musical INSTRUMENT. This dumbed down, crippled taster isn't really cutting it, for me at least. Several features with great unrealized promise...
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An arranger is just a tool. What matters is what you build with it..!