I have the similar experience as well!
One is with the BlueRay disc "Master and Commander" there was a sudden big "band" in the middle of a quiet scene. That was a really loud "band" I was so shock at that time. After I tried the same disc with PS3, same things happened, I took that back to the shop and tried, everything was ok! same as it when played in my friends system. So I consider it was the AV Amp encoder.
I have the same experience recently with the "蔡琴 concete too" when played in Dolby truHD 5.1, but since I mostly listening in PCM mode, so I did not affect me too much!
I still think that has nothing to do with cable connection but the decoder problem.
Oppo83
Marantz SR7005 + 淘宝6L6 膽機仔+Audio Space Mini II
Velodyne SPL800 Ultra
Line Magnetic LM215CD
馬Sir DAC; Fostex FE103E 座地 speaker
Linkwitz Lab - Pluto DIY