Okay, the video isn't broadcast quality. But at least you can get and idea and listen to some different sounds. This was the first attempt (my brother shot the video for me) and I edited. Seems like the resolution went down quite a bit after posting. I'll try higher quality uploads next time.
BLI NW2 with QSI factory installed.
http://www.youtube.com/watch?v=KhHpRGTLI0s
Old Athearn (bluebox) F45 with Soundtraxx LC101 (2nd generation EMD)
http://www.youtube.com/watch?v=-i7SRcgqVeU
Athearn RS3 with Soundtraxx DSX (TCS for motor and lights)
http://www.youtube.com/watch?v=vPwtfI0VASg
http://www.youtube.com/watch?v=QU8TZLizDwk
Athearn SD40T-2 with Digitrax Soundbug
http://www.youtube.com/watch?v=SEGM1ifphZU
The SD40T-2 and the RS3 both have the same speaker and enclosure: 16x35mm oval. The oval in the F45 is slightly larger. I would NEVER do another install with a separate sound decoder (DSX) again. It is too much of a pain to program. The Soundbug is the generic diesel sound scheme that comes loaded on it.
As soon as I get the chance, I have an Athearn MP15 with a QSI Quantum Revolution that I will shoot along with a BLI AC6000 with factory QSI. Hopefully, I'll learn how to post better looking video then.