Big time different combos... but...
8mm pulleys, 2" wide belt -
http://www.youtube.com/watch?v=LW-9NV0VDMQ
14mm pulleys, 3" wide belt -
http://www.youtube.com/watch?v=4Gm2d0s409U
I'd say the 8mm is more of a whistle, where the 14mm is more of a scream.