Dolby Pro Logic II or Logic 7: What Do you Prefer?

[gene]

Before there was Dolby Atmos, or even discrete 5.1 surround sound, there was matrixed surround decoding based off a discrete two-channel feed. Ever wonder how Dolby Pro Logic II came about and how it leapfrogged the original Pro Logic decoding?

Industry vet Paul Scarpelli recounts a historical perspective on 6-Axis surround originally developed by Jim Fosgate and how it battled Harman's very own Logic 7 format to be the next generation defacto surround decoder. Read about the silent format war and the battle to win Dolby over for Pro Logic II.

Read our article on: The Battle for Dolby Pro Logic II

Do you think Dolby made the right choice?

 

[Seth=L]

Intriguing. Does it matter what choice Dolby made? Dolby still holds the market as near as I can tell.

 

[Audioplus]

Feeling a bit snubbed by former colleagues, I must comment that back in ProPlus technology days and prior to the Harman acquisition, 25% of our gross sales were export. Even 35% of sales in 1989 were attributed to the 'Gavotte' a 5 channel surround decoder that was 12 Volt based. What made ProPlus superior to Pro Logic was that there was 60dB of separation (Paul correct me if I'm wrong) between all 5 channels and discreet, full range bandwidth to stereo rear channel separation. When Jim recruited John Dunlavy to design our THX speakers (John was adamant against the controlled vertical dispersion characteristics of the front L, C, R channels and the out of phase tweeter characteristics of the surround di-pole design speakers. I worked and supported the export, as well as assisting John Dunlavy in the in-wall/on-wall design of the surround speakers. Basically, it was designed to cut out the footprint to fit within a standard 2X4" framed wall cavity, use gravity to hold in place and velcro as a secure backing format.
Having worked with Jim, Charlie, Paul, and Bob (Norma & Lezlee as well), Martin Wilcox and Peter Scheiber, was one of the highlights of my career and an opportunity unique to anyone living in Heber City, UT.
Respects are extended to all of you and thank you all for being incredible mentors!
Regards,
Dan Christians

 

[Jay Rudko]

I had a Gavotte II in my car way back when, and it was an awesome unit. Essentially, it did what Pro Logic II later did. One of the biggest advantages I found with both the Gavotte and today's PL II is the ability to properly decode recordings encoded in the QS/RM format. Being the "quaddie" that I was in the 70's and 80's, I amassed a fairly large collection of quad LP's. Those encoded in QS/RM decode note-perfect when played in the PL II Music mode. SQ records, while there's a surround effect, tend to be imprecise in rear channel placements as compared to the Audionics Space and Image Composer (which I also have, but doesn't do QS well). If the receiver manufacturers stop including PL II, not only will great decoding of QS be lost, but the great job that format can do to enhance stereo material will be lost as well.

 

[Seth=L]

I guess I should change my name to Donnie, because when I posted on this topic I was clearly out of my element.

 

[Paul Scarpelli]

I guess I should change my name to Donnie, because when I posted on this topic I was clearly out of my element.

You are redeemed by making a "Lebowsky" reference.

 

[Paul Scarpelli]

Feeling a bit snubbed by former colleagues, I must comment that back in ProPlus technology days and prior to the Harman acquisition, 25% of our gross sales were export. Even 35% of sales in 1989 were attributed to the 'Gavotte' a 5 channel surround decoder that was 12 Volt based. What made ProPlus superior to Pro Logic was that there was 60dB of separation (Paul correct me if I'm wrong) between all 5 channels and discreet, full range bandwidth to stereo rear channel separation. When Jim recruited John Dunlavy to design our THX speakers (John was adamant against the controlled vertical dispersion characteristics of the front L, C, R channels and the out of phase tweeter characteristics of the surround di-pole design speakers. I worked and supported the export, as well as assisting John Dunlavy in the in-wall/on-wall design of the surround speakers. Basically, it was designed to cut out the footprint to fit within a standard 2X4" framed wall cavity, use gravity to hold in place and velcro as a secure backing format.
Having worked with Jim, Charlie, Paul, and Bob (Norma & Lezlee as well), Martin Wilcox and Peter Scheiber, was one of the highlights of my career and an opportunity unique to anyone living in Heber City, UT.
Respects are extended to all of you and thank you all for being incredible mentors!
Regards,
Dan Christians

Yup, Dan was there with us for the Fosgate-Audionics part. It was fun until our rapid growth almost put us under. It's good to hear from you, Dan, and I hope you're doing well. And don't feel snubbed; you were a big part of it.

 

[andyblackcat]

Intriguing. Does it matter what choice Dolby made? Dolby still holds the market as near as I can tell.

Yeah it does they axed Left-centre right-centre and made it a mess for Dolby digital least for the home. No classic 70mm will find its way into the home with 5 screen no thanks to Dolby labs.

Sony SDDS puts 5 screen back behind the screen and with stereo surrounds I think that was good format that I never heard. But I understand what the five screen is.

To bad with all this mumbo jumbo, atmos. Still all the classic 70mm 5 screen are been denied for home release all we get bloody 7.1 re-mix. Why not put the LC RC onto rear stereo back and let me worry about re-plugging it to 2 more matched speakers at the front.

Matrix up diy five screen matched is easy with matched matrix decoders. But its not the real thing but works and its cheap. I doubt the PLIIz works in same way as 5 matrix maybe close, but not the same way.

We need the real thing for the odd so many 70mm 5 screen mixes.

I need an ice-cream.

 

[mark123]

Hate to respond to a old thread, but here's a bit of history I picked up years ago. Thought the Fosgate/Audionics and the HK Citation guys might get a kick out of it.

 

[gene]

 

[Alastair]

I really enjoyed this video. I did not know at the time but a couple of years ago I exchanged some posts with Roger on the topic of a legacy Classe processor on another forum.

I can’t support the newer expanded sound fields - I have only just got to 5.1 - but I do enjoy what PLII as well as Trifield (Meridian’s passive option) can do, extending 2ch stereo content.

I have a test disc that pans audio through 360 degrees and it is amazing how PLII reproduces this. Standard stereo works well, I can live with it however why only settle using 2 speakers when you can have 5 (or more) at your disposal!

 

[j_garcia]

DTS:X

PLIIx and PLIIz were pretty good as well for years. With the inclusion of height speakers now and formats that support them, I find adding those to the mix, even for music, sounds pretty good without sounding gimmicky. It makes the front stage feel very large.

 

[William Lemmerhirt]

DTS:X

PLIIx and PLIIz were pretty good as well for years. With the inclusion of height speakers now and formats that support them, I find adding those to the mix, even for music, sounds pretty good without sounding gimmicky. It makes the front stage feel very large.

I think you mean DTSnx(neural x)?

I have ended up using DSU mostly for upmixing. DTSnx seems to put a lot of music content in my tops. While it is using the speakers more, I don’t really like it.

 

[j_garcia]

I think you mean DTSnx(neural x)?

I have ended up using DSU mostly for upmixing. DTSnx seems to put a lot of music content in my tops. While it is using the speakers more, I don’t really like it.

Yes, Neural. it depends on the track I think. Some it does put too much in the heights.

 

[gene]

DTS:X

PLIIx and PLIIz were pretty good as well for years. With the inclusion of height speakers now and formats that support them, I find adding those to the mix, even for music, sounds pretty good without sounding gimmicky. It makes the front stage feel very large.

DTS:X upmixer is absolutely horrible sounding for 2CH upmixing, sadly. It dumps the entire front soundstage into the center channel with no adjustability.

 

[lovinthehd]

With the relatively few units emplying the Logic 7 just not something I've run across but always has had great recommendations so I'd try it if I could....

 

[j_garcia]

DTS:X upmixer is absolutely horrible sounding for 2CH upmixing, sadly. It dumps the entire front soundstage into the center channel with no adjustability.

It works well with DTS material adding heights. I have actually not tried it with stereo tracks. I normally don't try to expand 2ch to anything else, I like it as 2ch.

 

[snakeeyes]

I like using DSU with Apple Music 2ch songs on AppleTV 4K. The DTS NeuralX seems to overload the center channel. (At least for my taste in my 5.1.4 setup)

 

[Trebdp83]

Unfortunately, DTS Neural:X does not have a Center Spread feature such as Dolby and even Dolby Center Spread is inaccessible in different receivers playing different dolby tracks such as Atmos. I can work around center centric sound in my own setup when using Dolby or DTS processing by using Onkyo's "VOCAL" feature which spreads center channel info out to the fronts. The effect can be adjusted to varying degrees. But, I usually play two channel music in stereo mode these days or sometimes in Pure Direct without the subs. Sometimes less is more.

 

[gene]

This article is republished in memory of Jim Fosgate who passed away 12/9/22. RIP to an industry legend. Gone but not forgotten.