Dialogue Dropout Problem in Surround Speakers

[voodoo_daddy]

I just set-up a new system, but I am having the following problem.

While watching DVD's, Planet Earth and others, I have been experiencing a dropout or out of phase sound from dialogue only and in my surround speakers only. The voice will move in and out of the left and right surround speakers.
This is very distracting and I cannot figure out why its happening.

My set-up is:

HK AVR146
Ascend CBM-170SE - F/L
Ascend 340c
Onix x-ls - SR/SL
Philips 5982 DVD player

I have checked the speaker polarity (phase ) and my speaker cable connections and everything is correct.

Can the problem stem from that I am using a different brand of speakers for the surrounds?

Thanks.

 

[Hi Ho]

How is the DVD player connected to the receiver? Are you using a digital connection or analog (red/white)? What you are describing sounds to me like anomolies in Dolby ProLogic processing. It happens sometimes, especially on TV broadcasts. If you are using a digital connection it may be that the Planet Earth DVD's are only mastered in 2 channel sound but I don't believe that to be the case.