QS MATRIX , ITEMS OF INTEREST (Billboard 1972-1976)

[kfbkfb]

https://worldradiohistory.com/Archi...ng-Engineer/70s/Recording-1973-12.pdf#page=26^^^
The Sansui QS "Mono Broadcast" mode is
a decoder function, whereby a 90° right
channel phase shift is used to obtain a
mono signal that maintains 360° signal
content to within 3 dB


Maybe the people involved with the Quark project could implement this mode to offer a mono compatible downmix of QS (as a separate music data file or streaming file), the QS mono broadcast mode doesn't require modifying the quad mix to be more mono compatible.


Kirk Bayne

 

[jaybird100]

In stereo, SQ pulls the rear channels in toward the center. While it's true QS narrows the front channels slightly, it moves the rears to appear outside the plane of the stereo speakers, creating a widened effect. No matrix is perfect, for sure. But isn't it interesting that, in some recent new releases are using Regular Matrix-based systems, of which QS is one, are still being used?

 

[par4ken]

In stereo, SQ pulls the rear channels in toward the center. While it's true QS narrows the front channels slightly, it moves the rears to appear outside the plane of the stereo speakers, creating a widened effect. No matrix is perfect, for sure. But isn't it interesting that, in some recent new releases are using Regular Matrix-based systems, of which QS is one, are still being used?

Only SQ retains (theoretically) perfect channel separation across the front. QS sounds very narrow by comparison. The effect of sound outside the speakers with QS is purely a psychoacoustic phenomenon, dependant on many factors. IMHO not real separation.

The use of QS/RM based encoding systems likely has more to do with better compatibility with Dolby PLII than better performance/stereo compatibility. Involve's encoding is rather cool, variable encoding coefficients yielding 12dB separation in stereo, Circle Surround does something similar. In any case I feel that the point is moot, with modern discrete systems available there little reason to encode anything anymore!

 

[fizzywiggs41]

QS is also more compatible for stereo playback, and loses less when listening in mono, as on some older car radios.

I think all matrices are compatible for stereo playback .
And QS looses sound or sounds on mono playback , whereas SQ does not . Rather a minor thing as almost no one listens in mono anymore.

 

[par4ken]

I think all matrices are compatible for stereo playback .
And QS looses sound or sounds on mono playback , whereas SQ does not . Rather a minor thing as almost no one listens in mono anymore.

Except for "kids" with their smartphones.

 

[fizzywiggs41]

Except for "kids" with their smartphones.

Touche' ,Ken.

 

[gvl_guy]

Except for "kids" with their smartphones.

Actually, I think smart phones are actually stereo. (At least mine is.) But my Google Nest or Alexa? I'm not so sure.

 

[MidiMagic]

Matrix is needed for the phonograph record that is gaining popularity again.
Matrix works on all recording formats sold to the consumer.
Nothing is sold mass-market that plays CD-4 today.
A simple passive matrix decoder (see image) can work with many of the players sold today.

Anyone can use this. It is my design and is in the public domain. It plays DS, QS, EV, and DQ.

It is much easier to find or make something that plays QS, DS, and other RM and QM variants than it is to find something that plays SQ and PM recordings. There are also a lot more recordings in QS and DS.

The mono compatible QS downmix mentioned cannot be in the same signal that contains the QS stereo/quad program.

There are a lot of mono radios around, including most clock radios and small tabletop radios. Too much of the stuff is Bluetooth rather than stereo.

Older people like me want to play our existing collections, rather than acquire many new recordings.

There was an article on Yahoo today: 25 greatest songs of all time. All of them were after 1950 and mainly rock genre. Slightly biased list.

 

[jaybird100]

Only SQ retains (theoretically) perfect channel separation across the front. QS sounds very narrow by comparison. The effect of sound outside the speakers with QS is purely a psychoacoustic phenomenon, dependant on many factors. IMHO not real separation.

The use of QS/RM based encoding systems likely has more to do with better compatibility with Dolby PLII than better performance/stereo compatibility. Involve's encoding is rather cool, variable encoding coefficients yielding 12dB separation in stereo, Circle Surround does something similar. In any case I feel that the point is moot, with modern discrete systems available there little reason to encode anything anymore!

Actually, there is. Discrete quad, although a system did get FCC approval, there's nothing out there to receive it. On the other hand, matrixed quad can be broadcast, just like any stereo recording. With a QS, or SQ, encoded source, it's just like playing a stereo recording. A listener, with a Pro Logic II decoder can hear it with decent separation. With a QS, or Involve, decoder, the separation is better, yet. The mono listener can still get a good result; if anything's missing, it won't be all that obvious.

 

[kfbkfb]

In the case of QS encoded content, I was thinking about the (mono sound) smartphone listeners and using the QS mono broadcast mode to create a separate mono stream just for them (no special mono mix of the QS encoded content would be needed).


Kirk Bayne

 

[jaybird100]

In the case of QS encoded content, I was thinking about the (mono sound) smartphone listeners and using the QS mono broadcast mode to create a separate mono stream just for them (no special mono mix of the QS encoded content would be needed).


Kirk Bayne

There are many smartphones out there, those made by Samsung, for example, that can play in stereo through its own internal speakers. I use a Galaxy Note 20, and it does a pretty remarkable job of delivering nice stereo sound. Considering Samsung has a large share of the smartphone market, the QS mono broadcast mode just won't cut it. In fact, that mono mode would apply mainly for AM radio (since AM stereo has tanked), and few AM stations still broadcast a music format. Using that mono mode on FM wouldn't make sense, since there aren't many, if any, FM stations, with a music format, that don't broadcast in stereo.

 

[kfbkfb]

I was thinking about (for streaming services only):

1: QS encoded stereo stream [hopefully decoded w/SM ]

2: QS mono broadcast mode processed mono stream for smartphones w/single speaker

This approach wouldn't require any compromises in the QS surround sound mix (CB could be used) and would offer a quad to mono downmix with about the same compromises as a stereo to mono downmix (CF up ~3dB, for example).


Kirk Bayne

 

[gvl_guy]

I was thinking about (for streaming services only):

1: QS encoded stereo stream [hopefully decoded w/SM ]

2: QS mono broadcast mode processed mono stream for smartphones w/single speaker

This approach wouldn't require any compromises in the QS surround sound mix (CB could be used) and would offer a quad to mono downmix with about the same compromises as a stereo to mono downmix (CF up ~3dB, for example).


Kirk Bayne

This is a great idea. But is technology smart enough to know which stream to use based on your device? My phone, which is stereo, would need the stereo stream where someone with a mono-phone or an Alexa Smart speaker would need the mono feed.
Think they could develop something that would automatically switch between the two as needed?

 

[kfbkfb]

I don't know if smartphones et al. identify their abilities (as Internet browsers sort of do by providing their name and type), but the streaming user could just select which stream to listen to at a given time, perhaps the stream provider could note that the mono stream is a special downmix of surround sound designed to minimize the losses associated with a creating a surround sound to mono downmix.


Kirk Bayne

 

[gvl_guy]

I don't know if smartphones et al. identify their abilities (as Internet browsers sort of do by providing their name and type), but the streaming user could just select which stream to listen to at a given time, perhaps the stream provider could note that the mono stream is a special downmix of surround sound designed to minimize the losses associated with a creating a surround sound to mono downmix.


Kirk Bayne

Now the question is, are average people smart enough to know which one to choose.

 

[fizzywiggs41]

A&M had originally announced five albums that were slated for QS release in the US, including "A Song For You", from the Carpenters, and "Come From The Shadows", from Joan Baez. The latter was the only one of the five to hit the stores. The ad went on to say they were using an improved vinyl formulation for the quad releases, because in quad, "when the record pops, the whole room pops". I grabbed the Joan Baez album as soon as I saw it, and was very pleased with its sound. I had a Sansui QS-01 decoder connected to my system and, considering how good their first effort sounded, I was bummed that the others got tabled.

A&M/Ode had 2 QS albums released...Tommy/LSO and guests and
Carole King - Music.
Three Carole King QS albums were actually announced .....
Tapestry , Music , and Rhymes And Reasons.

 

[jaybird100]

A&M/Ode had 2 QS albums released...Tommy/LSO and guests and
Carole King - Music.
Three Carole King QS albums were actually announced .....
Tapestry , Music , and Rhymes And Reasons.View attachment 91366

Ode was a separate company, being distributed by A&M. As for Carole King's "Tapestry" album, I saw a copy once, when it first came out, but didn't grab it at the time. I haven't seen it since, and I've been kicking myself ever since for not having bought it as soon as I saw it. The five albums, in the ad that ran in Billboard, were all on the A&M label, not Ode.

 

[par4ken]

Ode was a separate company, being distributed by A&M. As for Carole King's "Tapestry" album, I saw a copy once, when it first came out, but didn't grab it at the time. I haven't seen it since, and I've been kicking myself ever since for not having bought it as soon as I saw it. The five albums, in the ad that ran in Billboard, were all on the A&M label, not Ode.

You saw a QS copy of "Tapestry"? The Ode albums other than "Music" were released in CD-4 in Japan.

I think that "Music" is the best sounding QS album ever. I wish that the others would have come out in the same format. I don't think that the "Tapestry" mix was very good, at least not in comparison to "Music".

 

[jaybird100]

I was thinking about (for streaming services only):

1: QS encoded stereo stream [hopefully decoded w/SM ]

2: QS mono broadcast mode processed mono stream for smartphones w/single speaker

This approach wouldn't require any compromises in the QS surround sound mix (CB could be used) and would offer a quad to mono downmix with about the same compromises as a stereo to mono downmix (CF up ~3dB, for example).


Kirk Bayne

You might also try the Involve encoding, which is RM, but with Involve's touches. Excellent compatibility with stereo and mono, too.

 

[par4ken]

Actually, I think smart phones are actually stereo. (At least mine is.) But my Google Nest or Alexa? I'm not so sure.

Even if they are stereo, they play as mono via the built in speaker. They output stereo via Bluetooth and via the headphone jack.