Why do my front speakers diminish with pro logic ii?

Question

First of all thanks for answering my question about only 2 speakers functioning with the television.

I now seem to have a similar problem again with the front speakers in that when I play music and movies that are not 5.1 my rear speakers dont work. I need to select pro logic ii on my dvd player for all 4 speakers to work but that causes my front speakers to go very low.

Please help.

Answer 1

Pro Logic and Pro Logic II employ matrix decoding to separate the sound elements and send them to the appropriate channels from the stereo feed.

This really only works well if the media you are playing is encoded for Dolby Surround to begin with, though. Otherwise, the results can be unpredictable. It won't cause damage, but it may not sound desirable or right.

If the stereo feed is actually two channel mono, for instance, all audio will go directly to the center channel as they are in perfect phase.

In matrixed surround programming, dialogue is usually mixed in perfect phase (the same on both channels) so the decoder will send the dialogue to the center. Offphase audio (sound that isn't perfectly matched on left and right channels) will go to the surround speakers while audio only on the left or right will stay on the left or right.

You may have to find other sound field modes in your equipment to allow you to use all the speakers without matrix decoding.