Pro Logic II vs. Dolby Digital 5.1

[ender2009]

Hi! I have an old receiver that uses Dolby Pro Logic II technology. From what I've gathered, Dolby Pro Logic II is a technology that converts stereo sound into 5 channels to "simulate" surround sound. It does this when I play back music.

However, if I am playing a blu-ray that is uses a Dolby Digital 5.1 track, or some other form of Dolby Surround, then what is being played? Is it real surround sound? Obviously it's not a stereo source anymore, and it sounds like "real" surround sound to me.

I'm using a Phat PS3 with an optical cable.

[Blu-Dog]

Originally Posted by ender2009

Hi! I have an old receiver that uses Dolby Pro Logic II technology. From what I've gathered, Dolby Pro Logic II is a technology that converts stereo sound into 5 channels to "simulate" surround sound. It does this when I play back music.

However, if I am playing a blu-ray that is uses a Dolby Digital 5.1 track, or some other form of Dolby Surround, then what is being played? Is it real surround sound? Obviously it's not a stereo source anymore, and it sounds like "real" surround sound to me.

I'm using a Phat PS3 with an optical cable.

It will play the native Dolby 5.1 track, all six channels, when it detects Dolby signals.

[BIslander]

Yes, PLII and DTS Neo:6 do nothing when the source is already 5.1.

[WiWavelength]

Originally Posted by BIslander

Yes, PLII and DTS Neo:6 do nothing when the source is already 5.1.

Are we including Dolby Pro Logic IIx (or IIz) in this discussion? If so, the answer above changes.

AJ

[BIslander]

Nah. The OP strongly suggests we're talking about a 5.1 system. But, yes, in a system with more than six channels, the answer is different.

[ender2009]

Thanks for the replies, guys! Sorry, but yeah, my system is an RCA RT2870. Dunno if that helps. I'm glad that I am getting true surround from the Dolby sources. It is a 5.1 system, and it is just regular PL II. Not PL IIx or anything like that.

[BillCinLR]

Unless your receiver can actually play Dolby DIGITAL and it sounds like it CAN'T, you will NOT get discrete surround sound. ALL you will get is the synthesized surround channels, but it still might sound pretty good until you get a modern receiver to compare it with.

Bill C

[Tech-UK]

from looking at the manual, your receiver will only accept Dolby Digital (DD/AC-3) and 2 channel LPCM via S/PDIF, both coaxial (RCA connector) and optical (Toslink) inputs. This means that you can bitstream DD from your player to the receiver. DD Pro Logic II is included (make sure its set to Movie mode and that Night mode is set to off specifically when bitstreaming DD), which will allow 2 channel LPCM to be matrixed in to 6 (5.1) channels. There is no DTS compatibility with this receiver. Either set your player to transcode DTS to DD or decode and output 2 channel LPCM, Pro Logic II will then play its part .

[ender2009]

Thank you all! Yes, I have done more research, and my receiver does in fact decode Dolby Digital, as Tech-UK has stated. I was initially confused because sometimes movies would sound like it was "real" surround sound (which I found out later was when I was playing blu-rays with a Dolby Digital signal), and other movies would just sound like it was sort of repeating garbage in the rear speakers (which were the movies with a DTS source). But I figured this out, and then figured out how to set my PS3 to decode the DTS tracks.

It is a hassle having to switch settings on my PS3 every time I play a movie that is DTS, but it is definitely worth it, and they also sound really good! Thanks for all the help!

[Tech-UK]

Originally Posted by ender2009

Thank you all! Yes, I have done more research, and my receiver does in fact decode Dolby Digital, as Tech-UK has stated. I was initially confused because sometimes movies would sound like it was "real" surround sound (which I found out later was when I was playing blu-rays with a Dolby Digital signal), and other movies would just sound like it was sort of repeating garbage in the rear speakers (which were the movies with a DTS source). But I figured this out, and then figured out how to set my PS3 to decode the DTS tracks.

It is a hassle having to switch settings on my PS3 every time I play a movie that is DTS, but it is definitely worth it, and they also sound really good! Thanks for all the help!

Glad you got it sorted . Are you downmixing DTS to 2 channel LPCM or transcoding to DD, I am not familiar with the PS3 .

[ender2009]

Originally Posted by Tech-UK

Glad you got it sorted . Are you downmixing DTS to 2 channel LPCM or transcoding to DD, I am not familiar with the PS3 .

Haha yeah, me too, thanks!

The PS3 is actually able to transcode DTS to DD, so I still get surround. Wahoo!

[Tech-UK]

Originally Posted by ender2009

Haha yeah, me too, thanks!

The PS3 is actually able to transcode DTS to DD, so I still get surround. Wahoo!

Good stuff. I my self am not a fan of Pro Logic II and DTS:Neo, as long as you are getting a DD bitstream, thats good.