Pro Logic History

[Lt1z323]

Hello all,

I'm hoping you can help provide some history on the older Pro Logic decoder. I'm well aware of the consumer active decoder that was available but I've read the first incarnation was actually a passive matrix. If true can anyone provide some info, possibly patent info. I'm guessing that it'd likely be similar to a Hafler matrix with a summed center but any info would help. I've been reading up on the patent for PL and the cited AES papers but can find nothing concrete on the passive version.

For that matter if anyone can provide any info on the history of Tate as a company I'd really appreciate it. Info online is very scarce.

 

[kfbkfb]

Dolby Surround was called Dolby Stereo in the early years, it was changed to being called Dolby Surround in the mid-1980s.

https://en.wikipedia.org/wiki/Dolby_Stereo

(seems like many of the links at the bottom of this wiki page could be useful in understanding Dolby MP/Stereo/Surround matrix encoding)


Kirk Bayne

 

[lotones]

Hello all,

I'm hoping you can help provide some history on the older Pro Logic decoder. I'm well aware of the consumer active decoder that was available but I've read the first incarnation was actually a passive matrix. If true can anyone provide some info, possibly patent info. I'm guessing that it'd likely be similar to a Hafler matrix with a summed center but any info would help. I've been reading up on the patent for PL and the cited AES papers but can find nothing concrete on the passive version.

For that matter if anyone can provide any info on the history of Tate as a company I'd really appreciate it. Info online is very scarce.

I listen to all my stereo music through Pro Logic II. Here is a short-ish history of Pro Logic:

Jim Fosgate: Of (Surround) Sound Mind

History of Surround Sound Processing: The Battle for Dolby Pro Logic II

Dolby Surround Pro Logic II - The Technology and the Sound

 

[Lt1z323]

I listen to all my stereo music through Pro Logic II. Here is a short-ish history of Pro Logic:

Jim Fosgate: Of (Surround) Sound Mind

History of Surround Sound Processing: The Battle for Dolby Pro Logic II

Dolby Surround Pro Logic II - The Technology and the Sound

Same, all my music is run through PLII and I'm a big Jim Fosgate fan. Have you ever heard 6-Axis? I was able to get my hands on an old Citation 5.0, it's pretty cool to hear the different generations of upmixers.

 

[Owen Smith]

Same, all my music is run through PLII and I'm a big Jim Fosgate fan. Have you ever heard 6-Axis? I was able to get my hands on an old Citation 5.0, it's pretty cool to hear the different generations of upmixers.

I liked PLII Music but unfortunately new AV amps and processors have Dolby Surround Upmix instead. It's a completely new decoder despite the name, and while it works very well (to my ears) for films and TV it is awful for stereo music. It puts far too much in the centre and probably rears.

 

[MidiMagic]

The patents expired, and they changed everything, ruining surround.

 

[lotones]

Same, all my music is run through PLII and I'm a big Jim Fosgate fan. Have you ever heard 6-Axis? I was able to get my hands on an old Citation 5.0, it's pretty cool to hear the different generations of upmixers.

No, never heard 6-Axis. I started with the original Pro Logic on an ole Harmon Kardon pre/pro, and while it may have been the quality of the pre/pro, I was pretty underwhelmed. Pro Logic II fixed everything that was wrong with the original and more. Surprisingly PL II spreads some older 4 - 8 track recordings better than modern discrete mixes imho (Sgt Pepper’s stereo mix, for instance, is more dynamic through PL II than the 5.1 mix, though it can’t match the increased resolution).

I liked PLII Music but unfortunately new AV amps and processors have Dolby Surround Upmix instead. It's a completely new decoder despite the name, and while it works very well (to my ears) for films and TV it is awful for stereo music. It puts far too much in the centre and probably rears

That’s what I’ve heard. And honestly that’s one of the reasons I haven’t upgraded to Atmos. I’m hoping they fix Dolby Surround’s music decoding before my latest pre/pro finally enters Valhalla.

(Listening to Ray of Light through PL II right now… the best it’s going to sound until Maddie blesses us with a surround mix…)

 

[mandrix]

I still have a receiver with PLII. I use it to run my height speakers. (in direct mode, not PLII)
Would be interesting to try it again, but moving equipment and re routing cables doesn't appeal to me, only to change it back.
Still I may try the PLII again at some point.
A PLII VST could be nice to have, if such an animal exists, since I mainly listen from the pc anyway.

I agree with @Owen Smith the Dolby Surround on my main AVR doesn't appeal at all, at least to me. I think the DTS Neural upmixing sounds better than the Dolby.

 

[Owen Smith]

I’m hoping they fix Dolby Surround’s music decoding before my latest pre/pro finally enters Valhalla.

It's supposed to have some sort of centre width control, but my AVR and many others don't have it. I doubt Dolby will change anything until the patents are due to expire again.

 

[par4ken]

It sounds like Dolby is reinventing the wheel again! I've never heard the new Dolby Surround decoding so in all fairness can not comment on that. I will however once again condemn Dolby PLII (music mode), it sounds like crap to me! Tate decoding or Vario-Matrix decoding is infinitely better.

Today we have Involve, so why bother using an inferior (Dolby) decode system?

 

[Owen Smith]

I will however once again condemn Dolby PLII (music mode), it sounds like crap to me! Tate decoding or Vario-Matrix decoding is infinitely better.

I've not heard a Tate or Vario-Matrix, and those are much harder to get hold of in the UK than the US. That also means getting into running and restoring close to 50 year old electronics.

Today we have Involve, so why bother using an inferior (Dolby) decode system?

Because many AVRs including mine do not have multi channel analogue inputs. Nor do they have tape loops which made adding such processors simple. If Involve had HDMI audio out I might give one a try, but without that it is impossible for me to add one to my system. I know you'll suggest running a legacy AVR with multi channel inputs, but I have other requirements for HDMI audio in. And I don't want to be stuck maintaining an old AVR.

 

[par4ken]

Because many AVRs including mine do not have multi channel analogue inputs. Nor do they have tape loops which made adding such processors simple. If Involve had HDMI audio out I might give one a try, but without that it is impossible for me to add one to my system. I know you'll suggest running a legacy AVR with multi channel inputs, but I have other requirements for HDMI audio in. And I don't want to be stuck maintaining an old AVR.

Understandable, however in doing so you are sacrificing superb surround from stereo sources. Your choice/decision I do respect that.

 

[SeeMoreDigital]

Lol... Convert the analogue signal to digital and design some software that more accurately performs like the original pro-logic audio

 

[Owen Smith]

Understandable, however in doing so you are sacrificing superb surround from stereo sources. Your choice/decision I do respect that.

The upmixers on my current AVR are so poor I listen to stereo sources in stereo.

 

[kfbkfb]

The upmixers on my current AVR are so poor I listen to stereo sources in stereo.

Could use this method (it's ~$15.60 now ):
https://www.quadraphonicquad.com/fo...decode-tech-articles.37002/page-2#post-829621


Kirk Bayne

 

[lotones]

It's supposed to have some sort of centre width control, but my AVR and many others don't have it. I doubt Dolby will change anything until the patents are due to expire again.

If what I’ve read is correct, a/v manufacturers can license both the Atmos/Doldy Surround package and the older package with PLII, but understandably none have. Dolby should have made PL II part of the Atmos package for legacy customers.

 

[lotones]

It sounds like Dolby is reinventing the wheel again! I've never heard the new Dolby Surround decoding so in all fairness can not comment on that. I will however once again condemn Dolby PLII (music mode), it sounds like crap to me! Tate decoding or Vario-Matrix decoding is infinitely better.

Today we have Involve, so why bother using an inferior (Dolby) decode system?

To each his own as they say, but I wanted to point out that the quality of PL II varied from manufacturer to manufacturer, and PL II itself got better over the years. The last implementation before Dolby Surround took over is able to decode and spread files up to 96kHz. The earlier versions were limited to 48kHz.

 

[Owen Smith]

If what I’ve read is correct, a/v manufacturers can license both the Atmos/Doldy Surround package and the older package with PLII, but understandably none have. Dolby should have made PL II part of the Atmos package for legacy customers.

Yeah no manufacturer is going to pay for two licences when for 99.99% of their customers just the newer one is all they want.

 

[lotones]

Also wanted to mention, the best part about the latest/last version of PL II being able to decode up to 96kHz is that all my stereo SACDs decode into 5.1 now.

 

[mandrix]

Yeah no manufacturer is going to pay for two licences when for 99.99% of their customers just the newer one is all they want.

What year were the last, supposedly improved PLII devices made? I think the receiver I have was made circa 2012 or thereabouts.

Actually I think it's older than that. Still works good though.