I have just got a pro logic 2 receiver. When I playback mp3's or other compressed audio using the pro logic 2 music or movie mode I get only what I can describe as garbage coming out of the rear channels. This doesn’t happen with all my mp3 files but a considerable number are affected. I was wondering why this happens? Is it normal?

Hi!

It is normal for VBR mode mp3s like "--alt-preset standart", "--alt-preset extreme" or any "-V" even at top bitrates. Also it is possible a result of CBR low bitrate mp3s. My advise is to use only ABR mode at around 256 kbps to encoding mp3 to preserve surround sound component.

Hi,

Thanks for that information. All of my vbr mp3's give artefacts out of the rear channels I have some low bit rate cbr mp3's, some of them are fine and others give very little sound and volume out of the rear channels I guess it depends on the track and encoder used. Now that have read dolby’s description of pro logic 2 it is easy to see why this happens. I think its time I re-ripped my entire collection in flac anyway.