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Discrete vs Matrixed Surround Effects Pedals, Units & Accessories
Old 23rd August 2007
  #1
Here for the gear
 

Discrete vs Matrixed Surround

Hi All,

I am preparing a small reserach project for a uni subject that examines the aesthetic differences between direct and matrixed surround.

I would be grateful for some pointers to some reading/references on appropriate technique/ method for doing this.

I am looking at setting it up very simply to examine 1. effects and 2. movement in the sound feild.

Pointers to other similar research would be great. I have tried to find info on early Dobly Labs research but no luck.

Manythanks.

Mary.
Old 23rd August 2007
  #2
Gear Nut
 

Do you mean 5.1 vs Lt Rt decoded via pro logic ?

Eric
Old 23rd August 2007
  #3
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dr.sound's Avatar
 

"Discrete vs Matrix"

This should be titled "Discrete vs Matrix".
Old 23rd August 2007
  #4
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Geert van den Berg's Avatar
 

Quote:
Originally Posted by dr.sound View Post
This should be titled "Discrete vs Matrix".
I agree that is much more clear, so I took the liberty to rename the thread.
Old 31st August 2007
  #5
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Question

I must admit, I am a little disappointed with the replies here.

If you are going to go the trouble of replying, please add some value to the forum and the postings, please!

With all the knowledge in this forum I would have thought a little more advice, assistance would be easy to provide.
Old 31st August 2007
  #6
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soundboy's Avatar
Have you called Dolby labs? I would start with them. Are you talking about Pro logic 1 and 2? With Prologic 1, you have to down mix a 5.1 or 7.1 mix to a 4.0 mix and then encode. So already you are losing stereo in the surrounds, and your boom channel needs to be routed to your LCR so you don't loose that info. So, it's a very different sounding mix.
Old 31st August 2007
  #7
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Geert van den Berg's Avatar
 

Quote:
Originally Posted by Mary View Post
I must admit, I am a little disappointed with the replies here.

If you are going to go the trouble of replying, please add some value to the forum and the postings, please!

With all the knowledge in this forum I would have thought a little more advice, assistance would be easy to provide.
I haven't added any info, because I didn't find much to say about the subject.

It's quite obvious what the benefit of discrete surround is. Once the surround is encoded into the stereo material there's always compromises on the audio quality and offcourse limited to a mono surround channel. Offcourse Dolby Stereo is quite a genius and it's cool that it exist and still very much in use as well, but for newer productions it's logical people choose Dolby Digital over Stereo. (Dolby Stereo = Dolby Surround).

Like mentioned before, there's a lot of PDF's with info to be found on the Dolby website.
Old 31st August 2007
  #8
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Geert van den Berg's Avatar
 

Quote:
Originally Posted by soundboy View Post
Are you talking about Pro logic 1 and 2?
I didn't know there were 2 Pro Logic's. Care to explain the differences?
Old 31st August 2007
  #9
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soundboy's Avatar
I believe Prologic 2 actually decodes to 5.1 or 5.0. I don't remember if the boom channel comes over. I don't think it does.
Old 31st August 2007
  #10
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minister's Avatar
the difference between PL I and PL II is explained in various places in the Tech Library section of the Dolby site.

download the PDF's for PLII and give them a read.
Old 1st September 2007
  #11
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hociman's Avatar
 

Post PL II = 5.0

Quote:
Originally Posted by soundboy View Post
I believe Prologic 2 actually decodes to 5.1 or 5.0.
It decodes to 5.0.
Quote:
I don't remember if the boom channel comes over. I don't think it does.
It does not.
Old 1st September 2007
  #12
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Quote:
Originally Posted by hociman View Post
It decodes to 5.0.

It does not.
Well, it sort of does if it is being decoded into a bass-managed system, like home theatre.
And the CP650 has a mode where it will do a bass-managed decode of PL II, just like a home system.

Philip Perkins
Old 1st September 2007
  #13
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soundboy's Avatar
I figured it didn't because of issues with bass management.
Old 1st September 2007
  #14
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Geert van den Berg's Avatar
 

Cool this is new to me, I'll indeed go look for documentation on the Dolby website! (thought I had read most of it already, but I suppose not...)
Old 1st September 2007
  #15
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minister's Avatar
Quote:
Originally Posted by Geert van den Berg View Post
Cool this is new to me, I'll indeed go look for documentation on the Dolby website! (thought I had read most of it already, but I suppose not...)
In the most basic terms, Neither Dolby Pro Logic I or PL II are truly "5.1".
Neither contains an LFE channel.
PL I is four channels: L,C,R,S.
Pro Logic II is five channels: L,C,R,LS,RS.
Yet both vaingloriously unfold from the encoding as a "2-channel" Left Total Right Total.
in this way, being a "phase matrix encoded" two channel format, it is surround without being 5.1

as to the difference, well, it is very easy to hear. discrete sounds clear, matrix sounds smeary, or blended. and yet....sometimes the LtRt is the "sound" of film. meaning frequencies blend well in the front. the rear always make my head feel funny....like a dog trying to understand what you are saying to him.

honestly, you can read about it at the Dolby site, and then you have to sit in a room and study it for yourself..and form your own hypotheses.
Old 1st September 2007
  #16
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Geert van den Berg's Avatar
 

Quote:
Originally Posted by minister View Post
Neither contains an LFE channel.
PL I is four channels: L,C,R,S.
Pro Logic II is five channels: L,C,R,LS,RS.
Yet both vaingloriously unfold from the encoding as a "2-channel" Left Total Right Total.
in this way, being a "phase matrix encoded" two channel format, it is surround without being 5.1

honestly, you can read about it at the Dolby site, and then you have to sit in a room and study it for yourself..and form your own hypotheses.
I know, I used to work in a studio that does Dolby mastering. But I didn't know about Pro Logic II...

And yes it's obvious that matrixed is a compromis, that's also what I said earlier. Though a lot of times the dialoque sounds a bit warmer to me... Which is weird, because once it's on the mod, it's still digital... maybe less compression than the 5.1 AC3?
Old 1st September 2007
  #17
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minister's Avatar
Quote:
Originally Posted by Geert van den Berg View Post
Though a lot of times the dialoque sounds a bit warmer to me... Which is weird, because once it's on the mod, it's still digital... maybe less compression than the 5.1 AC3?
no, it's because of the phasing.
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