Emulator

Ok, this one is... unique. DSP HLE in Metroid Prime Trilogy (R3ME01) has a very interesting audio problem. I'll show you. Videos are small cause dialup and because the video itself doesn't matter, but the audio is at full quality.

Video 1 - https://dl.dropbox.com/u/519564/HLEwoesPrime2Tri1.mkv

That pop only occurs randomly, so here's one that can be consistently reproduced.

Video 2 - https://dl.dropbox.com/u/519564/HLEwoesPrime2Tri2.mkv

It only occurs in Metroid Prime 1 Tri and Metroid Prime 2 Tri with DSP HLE and DSP on Thread OFF. Metroid Prime 3 Tri is unaffected, as are Metroid Prime 3 Wii, Metroid Prime 1 GC, and Metroid Prime 2 GC. And yes, you heard me, turning on "DSP on Dedicated Thread" fixes it. I have no idea why. It occurs on DirectSound, Xaudio2, and OpenAL, so audio backend doesn't matter. And of course, LLE is unaffected regardless of the DSP on Thread setting.

It appears to have started with the New-AX-HLE merger in 3.5-1154 (no surprise there).

Tested on builds:
3.5-1064 Win64 - Fine, as expected
3.5-1193 Win64 - Broken
3.5-1210 win64 - Broken

Tested on systems:

Core i5 3570K @ 4.7ghz
nVidia GTX275
Windows 7 x64