My 950, and I am sure it is the 950, gives a low frequency thump when changing sources. I have an ICBM between the 950 and a 770. The 950 has all speakers set to large and the ICBM has all crossovers set at 80Hz. If the thump has frequency components above 80Hz, I have not noticed it in any of the loudspeakers as only the subs seem to respond to the thump. I suppose I could disconnect my subs and find out. I have not experimented to find which of the 950 (blue dot) channels may be contributing to the thump. It could be any one or more of the 950 channels, as the all the bass from any channel is redirected to the subs. The amplitude of the thump is not objectionable, so I have just been living with it. Has anyone contacted Outlaw and found out if this thump is to be expected, or is it a defect found only on a few 950's?