Q about 128 bit MP3's vs CD's upmixed to 5.1 via Pro Logic II (1 Viewer)

[w9xat]

Hello Group


I have some music I had ripped to 128 bit MP3s about 10 years ago (hey shoot me, hard drives were smaller back then ) but the original CD's are long since destroyed (note to group - watch your toddler when she's near your CD collection ). I also recently purchased a 5.1 system. My question is does the Pro Logic II upmix not work the same on low-bit MP3s as it would on the original CD source? Would the "missing data" due to the compression cause the upmix to "rechannel" (is that a term?) differently?


Thanks to all

 

[Mikael Soderholm]

Well, PLII works by using the differences in the stereo signal (just like good old Pro Logic), so a mono signal would be hard to handle. I can't think of any reason why the low bit rate in itself should matter, however, but depending on how the mp3s were made, it might just affect it. Some mp3 encoders use joint stereo, where certain sounds are encoded in mono to save space, as the ear (supposedly) can not detect the difference. Maybe this might mess with the PLII encoding...

 

[w9xat]

Thanks for the response. The rips were done so long ago Ive forgotten what I used to do them. Maybe I just have to go re-buy the CDs. Hey its an excuse to spend the money on the Beatles Box Set even though I already have the whole collection