Lou Dorren: A new CD-4 Demodulator!!!

[wa6ubw]

psssttt... I know, but I cheated.

[Old Quad Guy]

Hello Lou,

I’m looking forward to the new CD-4 Demodulator. I have a large collection of CD-4 records.

I know you’ve spoken a bit about SQ decoding, and it is most likely the worse form of Quad ever invented. But nevertheless many recordings are SQ or QS only and we still need to deal with them. I am working with both vintage machines and computer script attempting the best possible decoding that’s available now.

My Question is this:

Is 100% decoding of SQ and QS recordings possible? Or is it like trying to take two glued pieces of paper and separating them. Is it possible to measure the db of separation one is getting from machines or computer decoding?

The Tate machines go for big bucks $$$ and as I understand it once their chips are fried, so is the machine forever. Is it theoretically possible to build an SQ / QS decoder with off the shelf materials that could match or exceed what the Tate models can do without it costing an arm and leg?

Thank you for your advice and opinions!

[proufo]

I don't think you have to worry about Bush, he's on his way out. What you need to worry about are the marxists that are coming in. The republicans are in trouble because they promised smaller government and didn't deliver. But the alternative is much worse. There is no one that represents individual freedom in the presidential race. Or are you not for that?

The Quadfather

Marxisxts aren't the worst, as in recent decades they have accepted they were wrong. Only the deeply religious remain but they will die soon enough. Short-term-minded, gut-feeling, please-the-people-in-the-cheap-seats populists are the real danger.

[Quadro-Action]

If you will write more about political problems in your country USA I will do the same about those in Germany. It is a threat !!! he, he, he.
But there are really connections between Politics and Quadraphony: Sometimes annoyance. By quadraphonics yesterday (in hinsight of the commercials) and politics today. But we will have a quadraphonic pleasure, when the Dorren demodulator will be ready.

Dietrich

[proufo]

If you will write more about political problems in your country USA I will do the same about those in Germany. It is a threat !!! he, he, he.

You do that and I'll go along with Venezuela's and Colombia's. Now that's a threat!!

No, I won't. This place is for fun, delight and enlightement. Very little of that in V's and C's politics.

[Old Quad Guy]

Please put the politics in its own thread in the off topic section.

This is about the CD-4 Demodulator and it is disrespectful to Lou Dorren.

Now back to my question at post #277 and the subject of the new CD-4 Demodulator...

[Quadro-Action]

Hello Profou - I have had hope, all readers would find the joke between my message. But I think nevertheless, you have!

Dietrich

[Quadzilla]

.

[Justforthesoundofit]

Bass seems directional to me as well. Sitting in the average auto tells me the bass is coming from the rear. There may be a frequency below which you cannot tell the direction, or hear for that matter, maybe only feel. The problem with the “sub”woofer reasoning is that an instrument has harmonics that extend into the frequencies that we can tell the direction. It is hard to distinguish the direction and type of instrument if the main note comes from one speaker and the critical harmonics come from another, on the other side of the room. I remember a certain speaker advertising that their coils were in line vertically, to promote acting like a single speaker, “a single point of sound”.

I’ve been a “wanna-be” audiophile ever since, as a kid, I heard a high end stereo setup with Klipsch speakers. I though, “I can even hear her breath”. I could distinguish instruments! Being from the poor side of town, the best I had known before was the AM radio in our ’60 Chevy. My quad, as a teenager, was Q8 player in my car (Smoke on the Water, Money, etc) and a EV (which I still have, somewhere) adapter with a cheap Olsen amp for the rears. I remember using a kitchen chair, so I could sit in the “sweet spot” while listening to “They Only Come Out at Night”. I’ve wanted to get back to the excitement of the “sweet spot” ever since. Just didn’t have the money or time. But I’m getting there.

Thanks!

[Old Quad Guy]

Lou is one of the pioneers of CD-4 technology, and he has written (in this thread) that he did not believe that any matrix technology would do justice to quad playback. For this reason, I would say that he has no intention of building matrix playback into his design, nor should he want to. Dedicated, single-format circuitry is always preferable to so-called "universal" types. SACD/DVD-Audio technology should have proven that.

I understand that and I'm not asking for SQ / QS decoding to be put into the new CD-4 Demodulator.

What I'm asking is:

1. Is 100% decoding of SQ and QS recordings possible? Ever in any form machine or computer.

2. Is it theoretically possible to build an SQ / QS decoder with off the shelf materials that could match or exceed what the Tate models can do without it costing an arm and leg?

Because it is my understanding that to reverse engineer a Tate could cost possibly hundreds of thousands of dollars because of the chips.

[Quadzilla]

.

[Old Quad Guy]

What I'm asking for is Lou's opinion one way or another to my 2 questions.

[Quadzilla]

.

[Old Quad Guy]

Sorry, I didn't mean it to sound that way and thank you for your knowledge. I respect your opinion. Any input by anyone is most welcome.

I'm just intrigued to have Lou possibly answer these 2 questions with his engineering background and knowledge of Quad and that is only what I meant.

[The Quadfather]

The point of bringing up SQ in this thread is that's where Lou is. Of course, You could ask him to go over to the SQ thread, but it's hardly worth the trouble for one question. But one becomes two, two becomes three. So I will put in my two cent's worth. In spite of my big talk about having 5 ears and a big ol' bass ear, I really have only two ears. No, really, I'm not kidding. Yet I can tell direction of sounds in all directions, and so can all of you. If it was otherwise, you wouldn't like quad. The point is that our brains CAN sort it all out, with only two channels. So, this suggests that it could be possible to make a matrix decoder discretely separate the quad sounds, we just haven't developed the technology sufficient to do it yet. Also, it might be possible to wrap a stereo panarama around the room and have actual separation between the front speakers. Once again, this will require a technology yet developed. But as far as I can see, there is no will, so it probably will not happen within my lifetime. The future of multichannel is probably Blue Ray if anything. It seems to be winning the format war. Whether we will see any studio surround recordings in Blue Ray remains to be seen. But it will be possible, because the technology and infrastructure will be in place.

The Quadfather

[loudorren]

Hello Quadranarians,

Sorry I have not been here the last few days. I managed to get a terrific dose of the Rhino Virus. I, however, feeling better, think it is time for the "SOAP BOX".

Old Quad Guy, The information theorem is one of my favorite discussion subjects. It states that for a given number of input channels, there must be the same number of transmission channels, to reproduce to the same of output channels. This is then defined by 3 numbers. Take Discrete Quad for example. It is defined as 4-4-4, 4 input channels, 4 transmission channels, 4 output channels. It fulfills the Information Theorem perfectly. Now what about any of the matrix systems. These systems have 4 input channels, 2 transmission channels, and four output channels. They fail the Information
Theorem even with all the processors. This is because the 4-2-4 systems are all 2 channel stereo with 4 inputs and 4 speakers.

Here is an analog that should demonstrate what a matrix 4-2-4 system does. Imagine four soda glasses, each one half filled with a different soda. Glass 1 has orange soda, glass 2 has root beer, glass 3 has cherry soda and glass 4 has lemon soda. These are the 4 input channels with the color of the soda equivalent to the phase shift. Now imagine 2 empty glasses representing the 2 transmission channels. Now take input glass1 and input glass2 and empty the contents into transmission channel glass 1. Then take input glass3 and input glass4 and empty these contents into transmission channel glass 2.

Now here is the problem, having poured the orange and the root beer into the same glass, regardless of color, how do you separate them back into their original discrete soda form? The answer is you can not!! All the 4-2-4 matrix systems do is to mix (add) 2 signals on the left together and put them on the left channel and they do the same for the right channel. Phase shifting at audio frequencies serves no purpose unless you are using it as a "guitar effect".

Wait a minute, what about , Tate, Prologic etc.? Well these devices have an interesting effect. When the Information Theorem is satisfied, they can do something that appears to be correct. When the Information Theorem is not satisfied, they become quite confused. There are 2 conditions in matrix 4-2-4 where the Information theorem is satisfied. Condition number 1 is sending only 1 of the 4 channel at a time. The example is LF only with LB,RF,RB silent. In this case the Tate, Prologic,etc processors have enough information to turn the level down on LB,RF,RB and leave the level up on LF. If only one channel is sent at a time, the sound can be made to appear going around the room. Quadraphonic right? No, it is only a special effect! The minute there are more then 2 audio channels being sent, all bets are off. By the way, when all 4 channels are input on a 4-2-4 matrix system, there will be at least 1 pair of channels on the output that will have no more than 3dB of separation.

I know there are a lot of you out there with large libraries of SQ and QS records. I also know that some of these synthesized Quad records can sound interesting. I recommend that you enjoy them, but remember they are synthesized and not true Quad as is discrete Quad.

The answer to your Questions Old Quad Guy, no it will never be possible to decode 100% of a QS or SQ recording because there really was nothing encoded! Contrary to popular opinion, the Tate unit was not very complex and could be easily duplicated.

Quadfather, Good thoughts, and remember TAAS.

Lou Dorren

[kfbkfb]

Regarding CD-4 and Playback Turntable
RPM Accuracy:

Proper operation of CD-4 is predicated on
CD-4 discs being played back at exactly
the intended RPM.

How much of an RPM variation will the CD-4
system tolerate?

Kirk Bayne

[bad_robot]

Ah the Edgar Winter Group - they do only come out rarely now.
Now I see why QS and SQ matrix did seem to work - only when the other channels were quiet.

Got a quote on a shibate stylus 4MD10X $A229 and a 4 MD30x eliptical $A99.95 retail - so those stylus are getting expensive or its just a rip off - a total of $A330. But, from another retailer $A75 and $A55 - much better, I think.

Hope Lou has a final solution for the demodulator problem - disks will last well but a demod'r won't.

Cheers

[loudorren]

Hello Quad Fans,

kfbkfb, A +-5% variance is still usable. Direct drive and servo turntables are the best.

bad robot, You and everyone will be quite happy with the new CD-4 cartridge with Shibata stylus, both price and performance!

NEWS FLASH: Blu Ray wins High Definition War!! Toshiba to stop manufacture HDDVD today!

Lou Dorren

[quadtrade]

Hello Qyad Fans,

kfbkfb, A +-5% variance is still usable. Direct drive and servo turntables are the best.

bad robot, You and everyone will be quite happy with the new CD-4 cartridge with Shibata stylus, both price and performance!

NEWS FLASH: Blu Ray wins High Definition War!! Toshiba to stop manufacture HDDVD today!

Lou Dorren

Lou, perhaps good news for music fans, but i wonder if we just gave the keys to exxon and shut down the rest of the stations. Sony has fought tooth and nail to own every format(yep, you and i know that is where the big $ is) and it now wants to control everything from production thru distibution. This company is not gonna make it inexpensive to release material. It just seems to make it more difficult to see much material being released in real multichannel form for music only. If it was some other company else..... optimisim might win. I wonder if even a progressive place like Telarc will even make that jump.

[quadtrade]

Please put the politics in its own thread in the off topic section.

This is about the CD-4 Demodulator and it is disrespectful to Lou Dorren.

Now back to my question at post #277 and the subject of the new CD-4 Demodulator...

OQG,
nothing disrepectful towards Lou at all. In fact if we really think about it, this is a truly people driven project. Lou appeared out of nowhere and has an obvious delight in seeing this technology being used for all our pleasure. It has nothing to do with making lots of $. I know, i put out the Millennium! To accomplish what Lou wants to do at a price point we all will be willing to pay, is only because Lou is doing many hours of research and engineering that will not be accounted in the final price point. That is just a guess, but i know i am right. Plus we have been given rights to affect the final product with suggestions and even perhaps install a name upon its body! In a year which fat cat $ seems to control our lives, here is a proposal to do something by for and with the people. Very inspirational. Not enough to make me think about doing electronics on that scale again! But whatever Lou needs, let's help provide.

[Old Quad Guy]

I happen to agree with your tag. But I hate to see people getting pissed off about politics here, they are already doing that at home no matter what one’s belief is. Which is sort of a hypocritical thing to say considering I play anti-fascist old school punk rock since the early 1980’s meant to piss people off. Certainly if someone see’s something wrong they should exercise their free speech rights.

I used to run an entertainment company with strippers and I had to be the body guard for bachelor parties from time to time. One time the strippers were late to a party and the guys started getting real anxious and the conversations turned to politics. It was funny watching friends who we’re drinking beer all getting along one minute, starting to argue the next dividing into left .vs right, right .vs left. I had to laugh. Finally, the strippers arrived and everyone was happy on the same page again.

I want to thank quadtrade for all your hard work and dedication with Quadraphonic and for helping bring Quad into the next century. We are forever indebted to you for your work!

I want to thank Lou Dorren, Quadzilla and The Quadfather for answering the SQ Quad questions. It's something really important that needed to be answered once and for all. Thanks everyone.

[loudorren]

Hello Quad Supporters.

Quadtrade,
Ted, The Sony Blu Ray is far superior over the Toshiba HDDVD. The most important criteria is storage capacity. Blu Ray is capable of multi layer storage eventually beyond 500 GB. HDDVD was limited to 25 GB. This means that some day we may actually get real High Definition Television without throw away digital data compression!

Old Quad Guy, Is that you behind the mixing console? What studio?

Lou Dorren

[Old Quad Guy]

Old Quad Guy, Is that you behind the mixing console? What studio?

Hello Lou,

No, it is not me...yet! Although I’m getting there bit by bit. I picked this as my avatar with much respect for the engineer in the photo (who I wished I knew more about), and that I will someday be lucky to live long enough to contribute something positive with music and Quadraphonic preservation. It is a photo of Grammy Award winning sound engineer Carson Taylor at an actual Quadraphonic recording/mixing station working on a Quad track at Capitol Records' Hollywood studios in 1974. The full photo shows a speaker behind him. It comes from the back of a Capitol Quad sampler “Magnavox Presents a Sound Experience.”

Old Quad Guy

[herby]

Regarding CD-4 and Playback Turntable
RPM Accuracy:

Proper operation of CD-4 is predicated on
CD-4 discs being played back at exactly
the intended RPM.

How much of an RPM variation will the CD-4
system tolerate?

Kirk Bayne

The tolerance of the CD-4 demodulator is probably the LEAST of your worries. While not everyone has perfect ABSOLUTE pitch (some do, like Lou), most everyone has very good relative "perfect" pitch. It is well known that when silent movies were made, the speed of the "recording" often varied from camera operator to camera operator. When they went to sound recording synchronized with the action on the film, they needed to standardize on the frame rate (24fps) to make everything work correctly. If you have an adjustable speed turntable, try to play something and alter the speed. You will notice it VERY quickly, and it doesn't take much. It turns out that your ears are better pickups than your eyes. We humans can tolerate quite a bit of distortion in the picture, but very little in the sound. This is one of the reasons that video is more compressed (ratio wise) than the sound in MPEG style recordings.
Of course, the best is no compression at all, hopefully BluRay will assist in that someday.