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MidiMagic

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PL II decodes them. Saying it does so correctly ie placing everything where it was originally meant to be, is not true.
Yes, it does place then correctly. For EV4 and DQ, you need to move your chair forward.

I have tested it with correctly encoded signals.
 

Owen Smith

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Yes, it does place then correctly. For EV4 and DQ, you need to move your chair forward.

I have tested it with correctly encoded signals.
The encode and decode equations for QS are not the same as DPLII, nor are either of those the same as EV4 or DQ. It may produce reasonable sounding results on 4 corners or limited positions test tones, but that is not the same thing as decoding everything to the locations they are meant to be in.

EV4 and DQ aren't even phase matrices, so running them through a decoder for a matrix that does use phase is going to produce incorrect results.

Note incorrect results is not the same as "sounds nice". All of these options can produce nice sounding results.
 

par4ken

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Yes, it does place then correctly. For EV4 and DQ, you need to move your chair forward.

I have tested it with correctly encoded signals.
Depends what you mean by correctly. If you have to mover your chair technically I would not call that exactly correct. Reasonable sounding results as Owen says is actually fine in my books. So I would agree with you that they are all compatible even if not optimal.
 

DuncanS

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So with this take place of the demodulator and my receiver? Or just the demodulator
The SM3 needs a phono preamp to work, so it needs a preamp between the turntable and it. So the SM3 is then connected to the receiver. So you would need to switch the connections to the receiver between listening to a CD4 LP with the demod and using the phono preamp/SM3 to listen to SQ & QS matrix LPs.
 

BrentAudi

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I find that Dolby Pro Logic IIx does very will with SQ. The interesting part is that the SQ Test recordings with voice over explaining what is about to take place comes out only the center speaker where as on Vintage SQ Equipment it comes out as Stereo front L & R.
 

boondocks

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I have at least one decent SQ LP left, I never played it but a few times so should be in pretty good shape. I will give that a try with DP Logic and see how it goes.
Mahavishnu Orchestra, Live, Between Nothingness and Eternity. I just re-discovered it the other day. (recorded August '73 in Central Park)
It begs to be ripped but I no longer have that capability except....hmmm...I have an old 5 disc CD changer that also records if I can find it. Or to my HTPC? Not done this in a while, use Audition maybe?
24/96?
Time to hook the old TT back up. Getting behind the Audio Cabinet is a real PITA but.....
 

MidiMagic

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The encode and decode equations for QS are not the same as DPLII, nor are either of those the same as EV4 or DQ. It may produce reasonable sounding results on 4 corners or limited positions test tones, but that is not the same thing as decoding everything to the locations they are meant to be in.

EV4 and DQ aren't even phase matrices, so running them through a decoder for a matrix that does use phase is going to produce incorrect results.

Note incorrect results is not the same as "sounds nice". All of these options can produce nice sounding results.
Depends what you mean by correctly. If you have to mover your chair technically I would not call that exactly correct. Reasonable sounding results as Owen says is actually fine in my books. So I would agree with you that they are all compatible even if not optimal.
I find that Dolby Pro Logic IIx does very will with SQ. The interesting part is that the SQ Test recordings with voice over explaining what is about to take place comes out only the center speaker where as on Vintage SQ Equipment it comes out as Stereo front L & R.

You are so involved with looking at the differences in the math that you are overlooking one thing.

It doesn't matter what the signals look like on paper, where the speakers are placed for the system used, or which speakers have the signal in them. What matters is the direction where you hear the image for each of the sounds encoded on the recording.

This math matters only to the discrete-seeking purist, but you still hear the same thing.

All of these systems are RM. It doesn't matter where the speakers are or at what angles they decode at. It matters where the listener hears the sound from.

- If the sound is coming from only one speaker, can you hear whether it was recorded with a psi+0 phase or a psi+90 phase? NO!

- If the sound is coming out of one center channel speaker, does it sound any different from a sound that is the phantom center created by left and right speakers?

All of those systems should produce the same sound image for the same recording (except that Dolby Surround and Pro Logic let you hear sounds between the side speakers that the others can't do).

It is my experience that recordings in all of these systems (QS, D-diamond, QX, and DS) all sound alike when played on any of these systems.

The reason for moving the chair forward is that the EV and DQ matrix decodings have the front channels with wider separation than the back channels.
 
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Owen Smith

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EV-4 and DY are not RM, period. RM is a phase based matrix and neither EV-4 or DQ are. Any phase differences in EV-4 and DY recordings are nothing to do with quad encoding.
 

par4ken

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EV-4 and DY are not RM, period. RM is a phase based matrix and neither EV-4 or DQ are. Any phase differences in EV-4 and DY recordings are nothing to do with quad encoding.
Technically by the Japanese definition of RM, you could be right. What we are referring to as RM here is really the Schreiber system. By considering that system as a kernel rather than a matrix system, signals can be "encoded" in any position around a 360° arc or circle, without regard to actual speaker placement. That is what Midi is getting at. With EV-4 the rear "channels" will sound a bit closer together, while front ones will sound a bit more to the sides. They still are all encoded with their own separate defined positions around that curve. EV-4 and Dyna as well Dolby surround all decode very well via QS, the first two will just have their actual decoded positions moved slightly.

I don't know what you mean about phase differences in EV and Dyna having nothing to do with quad encoding? That's how they work!
 

Sonik Wiz

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What we are referring to as RM here is really the Schreiber system. By considering that system as a kernel rather than a matrix system, signals can be "encoded" in any position around a 360° arc or circle, without regard to actual speaker placement.

I like how you pointed this out. Or put another way, using a decoder with known coefficients, such as Scheiber's, any direction can be predicted by a known polarity/amplitude input. In other words for any direction 360 deg there is a corresponding relationship from the encoder. The original EIAJ RM specs had nothing do do with pair wise multi-track mixing or number of chs. Just direction.

SQ & UHJ are two examples of phase matrix encoding. RM is not because it uses just amplitude & polarity.
 

Owen Smith

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Well, having two substantially different meanings of RM does not help us understand each other. I'm using the Japanese one.
 

par4ken

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I recently stumbled upon this bit about RM.


This article might cloud the waters a bit more as the author considers the systems that were brought into the RM standard to be incompatible with each other. I would suggest that is only true if your definition of compatible is identical. QS became commonly known as Regular Matrix but is actually the most different because of the use of 90° phase shifters. Dolby Surround uses the same phase shifting as QS.
 
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MidiMagic

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EV-4 and DY are not RM, period. RM is a phase based matrix and neither EV-4 or DQ are. Any phase differences in EV-4 and DY recordings are nothing to do with quad encoding.
Technically by the Japanese definition of RM, you could be right. What we are referring to as RM here is really the Schreiber system. By considering that system as a kernel rather than a matrix system, signals can be "encoded" in any position around a 360° arc or circle, without regard to actual speaker placement. That is what Midi is getting at. With EV-4 the rear "channels" will sound a bit closer together, while front ones will sound a bit more to the sides. They still are all encoded with their own separate defined positions around that curve. EV-4 and Dyna as well Dolby surround all decode very well via QS, the first two will just have their actual decoded positions moved slightly.

I don't know what you mean about phase differences in EV and Dyna having nothing to do with quad encoding? That's how they work!
I like how you pointed this out. Or put another way, using a decoder with known coefficients, such as Scheiber's, any direction can be predicted by a known polarity/amplitude input. In other words for any direction 360 deg there is a corresponding relationship from the encoder. The original EIAJ RM specs had nothing do do with pair wise multi-track mixing or number of chs. Just direction.

SQ & UHJ are two examples of phase matrix encoding. RM is not because it uses just amplitude & polarity.

It's spelled "Scheiber". I used to know him.

The The Japan Phonograph Record Association (JPRA) and the Electronic Industry Association of Japan (EIAJ) each produced very similar standards for matrix recordings:

RM - Regular Matrix - Equal-separation basic matrix
QM - Quadraphonic Matrix - Forward-oriented basic matrix
PM - Phase Matrix - All SQ-related matrix systems
CD - Compatible Discrete - CD-4
UX - Uniform Matrix - All UMX-related matrix systems

RM: Pan determines left-right position. Polarity determines front-back choice. QS, DS
QM: Same as RM except wider front and narrower back separations. EV, DQ
PM: 90 degrees phase differences in back corners. SQ, EVU
UX: 90 degrees phase difference center front and center back. UMX, BMX, UD4

QS has phase shifting in the 4-corners encoder for the purpose of making the back channels encode without the 'hole' in the pan pattern found in the others. But the phase difference between encoded channels is always 0 deg or 180 deg.

ALL of the RM and QM matrix systems have the same stylus motions for the same encoded sound positions (excepting the separation differences for EV and DQ). I use the same encoder for all of them.

encodpan.gif


For EV and DQ, the pan control is set farther from center for LF and RF, and closer to center for LB and RB.
 
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