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Quadraphonic


dtr20

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My father @TomR recently got a Pioneer qx-949 quadraphonic receiver. He remembers in the 70s certain fm stations would broadcast in quadraphonic on Sunday night's only. We really want to experience quadraphonic, but we have no clue about it. We know there were turntables made, but they seem to cost a lot and still need work it replacement cartridges, etc. We don't want to spend a lot of money because we have a hunch that it will be very underwhelming. I know someone that has a quadraphonic reel-to-reel, but he didn't know anything else about quadraphonic. 

 

Any information that you guys might have would be helpful. We know we could always take Y splitters on the rca's from a 2 channel source and get the signal to all 4 speakers that way. Thanks guys

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quadrophonic was somewhat of a fad. I never heard it but I am sure it was quite good.  Not sure if you want to invest a lot in this as you will have to find records to play too.  Obviously you know you can't just simply split the rca output of a turntable to get Quad sound.  

 

After Cds appeard there was SACD as well as DVD audio could support 5.1 sound however they never really took off. I have a few 5.1 DVDs audio discs and they do sound amazing.  Unfortunately there is not enough demand for this format.  

 

Wiki has a good summary. 

 

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3 minutes ago, efzauner said:

quadrophonic was somewhat of a fad. I never heard it but I am sure it was quite good.  Not sure if you want to invest a lot in this as you will have to find records to play too.  Obviously you know you can't just simply split the rca output of a turntable to get Quad sound.  

 

After Cds appeard there was SACD as well as DVD audio could support 5.1 sound however they never really took off. I have a few 5.1 DVDs audio discs and they do sound amazing.  Unfortunately there is not enough demand for this format.  

 

Yea we know you can't just split turntable rca's. We would do it witha CD player. I love listening to sacd's and dvd-audio's, but like you said, not enough content out there

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11 minutes ago, efzauner said:

But even splitting a CD still is just duplicating left and right... You could just connect a pair of rear speakers to the B speakers of your amp. 

You are correct, just want to be about to utilize the some of the receivers capabilities

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1 hour ago, dtr20 said:

Yea we know you can't just split turntable rca's. We would do it witha CD player. I love listening to sacd's and dvd-audio's, but like you said, not enough content out there

I don't believe that you need a "quad" turntable, just a compatible cartridge/stylus, the four channels are derived from a demodulator fed a stereo signal. The qx-949 actually has the demodulator built in to it, some other receivers required a separate unit.

 

 

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There are quite a few SACDs with 3 to 5 channels on them, mostly classical or modern orchestral music or organ.  One company is restoring old Quad master tapes from the '70s and releasing them on SACD.  I forget the name, but Google or catalogs should help.  I've heard Dark Side of the Moon on SACD multichannel; it's very impressive.

 

 

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Quadrophonic was a blip on the radar for a while. It was no surprise to me that it didn't last. Quad recordings either had instruments coming from all around, or there was a conventional stereo presentation that would spin around the room at random times. Quad had a lot of potential but the record companies turned it into a gimmick.

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14 hours ago, Don Richard said:

Quadrophonic was a blip on the radar for a while. It was no surprise to me that it didn't last. Quad recordings either had instruments coming from all around, or there was a conventional stereo presentation that would spin around the room at random times. Quad had a lot of potential but the record companies turned it into a gimmick.

Agreed, I was in the army stationed in Hong Kong at the time of quads introduction, it was a must have thing amongst us squaddies. 

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JVC's CD-4 was the only TRUE four-channel put on vinyl.  It is also called "Discrete".  QS and SQ were both matrixed, which means they had a carrier signal which "told" the  matrix device used to send specific designated frequencies in varying signal strengths to the rear speakers to REPLICATE four-channel.  But as far as actually having FOUR SEPARATE channels, CD-4 was it.  Because there was a minute time lag while the rear channels were demodulated from the vinyl, a time delay was incorporated into the demodulator for the front two channels so that everything came out at the same time through the speakers/headphones.

 

In order to play CD-4/discrete vinyl, not only was a demodulator needed, but there were two other factors involved, the turntable itself (the wiring and circuitry from the cartridge to the  pre-amp inputs which the turntable had needed to be compatible with CD-4 usage, PLUS the cartridge, ALONG with its stylus had to be correct, and able to transfer the information needed in a much broader frequency range...due to the re-modulated rear signals that had to make unadulterated to the demodulator.  This extended frequency range needed went up to around 40 kHz or so, and most stereo cartridges just didn't have that ability.  The stylus also had to be CD-4 compatible.  Audio-Technica CD-4/Discrete cartridges were the leading seller for this.  Not only that, but the vast majority of name-branded CD-4 cartridges were just Audio-Technica models re-badged with another company's logo and possibly alpha-numeric part number on them.  The most-used stylus back in the day was a Shibata nude diamond elliptical stylus, and they were NOT cheap!  Their ellipse was MUCH narrower than a stereo elliptical stylus design and not even a true ellipse to begin with. I ran a JVC-badged Audio-technica cartridge which was about half or less of the going rate for the same thing with Audio-Technica badge on it. The one I had was rated 18 Hz to around 55 or 60 kHz, if I remember correctly. I think that cartridge is JVC 4MD-20X.

 

The downside to CD-4 was that record wear was its worst enemy.  Other enemies of it were improper stylus/cartridge alignment, and poor anti-skate and weight settings, which contributed to the record wear but ALSO caused improper decoding in the demodulator. The demodulator itself had to be adjust properly, too!

 

What did I use for my 4-channel turntable?  Technics Sl-1300.  What did I use for my 4-channel receiver?  H/K 900+ which had QS and SQ matrix built-in and also the CD-4 demodulator built in.  32 WPC, four channels driven, was more than enough for quad!

 

The biggest problem with CD-4 was that recording engineers for the most part just did not understand how to utilize it.  So, it became a toy, instead of reaching its true potential in the vast majority of recordings.

 

What was PWK's take on quad?  From what I heard it was something like this:  "You only really need three channels, a left, a right, and a center...and the right environment to put that in.  But, if they want to buy four speakers, then I will sell them four speakers."

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On 10/17/2016 at 6:49 PM, dtr20 said:

You are correct, just want to be about to utilize the some of the receivers capabilities

Just input stereo L and R.. the receiver should have a switch to send the same L and R to the rear speakers amps.  This should be a no brainer.  

Not sure if all of this is worth it.  If it is a great amp then use it, but for some sort of synthesized surround, current HT receivers have a number of surround effects for stereo.

Specs say 60wpc stereo, 40wpc into 4 channels.   Seems it was a very complete quad receiver. lots of bells and whistles and looks cool.  If this is your only vintage receiver and want to enjoy LPs and the vintage experience then go for it.  Not going to be worth setting it up for quad. 

 

http://classicreceivers.com/pioneer-qx-949

 

 

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I appreciate that you are trying to help your father in exploring quadraphonic, but IMO it's not worth pursuing.  Even at best it was a fad, one that has very few advantages with very few albums.  Of course the few that are out there are from 45 years ago.  It seems the big novelty was Brain Salad Surgery with the sound going around your head in a circle.

 

It will be a lot of time and money spent for a short term trip down memory lane.

 

 

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  • 8 months later...

Dear dtr20:

 I was checking out the web for "other" quadraphonic sites, when I ran across this Klipsch site. I can answer your questions and steer you in the right direction. Quadraphonic is much more than double stereo using splitters. The premier quad website is QuadraphonicQuad.com, and there you will find the quad community, and much modern and up to date information about legacy quad and modern multichannel surround sound for music. As stated above, quad was a bit of a fad, but it was a long running one, and much music was produced in quad. So if you like 70's music, it would definitely be worth checking out. Quad had a lot of technical problems to begin with but most had been worked out by the time of it's demise, and some worked out even afterwards. That Pioneer QX949 was a fine receiver, but the Pioneer SQ decoders weren't very good. The separation was poor. If I'm not mistaken, that receiver also had a CD-4 demodulator built in. CD-4 demodulators required a good signal, and most of the cartridges of the day weren't capable of providing it. Modern microline cartridges made by Audio Technica perform well. I use the AT 440MLa. The AT440MLb works equally well, although neither is "rated" for quad, listing a frequency response that falls far short of what is required. AT does have cartridges that rate up to 50KHZ if you want to spend the dough. As for turntables, they just have to have low capacitance wiring. Most high quality turntables of the day qualify. (look for thick "video like" cables). And as for CD-4 record wear, that's a myth. In the early development of CD-4 that was a problem, so JVC developed super vinyl, which was used from that point on. All my CD-4 albums play with separation intact.If you or any of these other folks want to learn more about quad, check out QuadraphonicQuad.com. It's worth pursuing if you like multichannel music.

 

The Quadfather

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On 10/17/2016 at 3:30 PM, efzauner said:

quadrophonic was somewhat of a fad. I never heard it but I am sure it was quite good.  Not sure if you want to invest a lot in this as you will have to find records to play too.  Obviously you know you can't just simply split the rca output of a turntable to get Quad sound.  

 

After Cds appeard there was SACD as well as DVD audio could support 5.1 sound however they never really took off. I have a few 5.1 DVDs audio discs and they do sound amazing.  Unfortunately there is not enough demand for this format.  

 

Wiki has a good summary. 

 

 

 

Classical/orchestral SACDs in 5.1 are still available.  Pentatone, etc.  One of the magazines regularly reviews "Music in the Round;" perhaps it is Stereophile.  

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 I remember quad!  The first time I heard it was through Klipschorns in the front and Belles in the rear.  It was a live performance and it made that small room sound like the 7500 seat Municipal Auditorium!  There were several add on decoders and receivers with them built in.  LPs had quad encoded in the grooves, but your cartridge had to be capable of something like 40kHz.  I imagine most modern moving coil units can do it now, *if* you can find quad LPs.   I'd love to hear it again to see if it was as good as hype/memory thought it could be. 

KDAFMLEFT.jpg

 

This is not the coolest quad promo, though.  The best one was played after midnight, when Clark Rogers was on.  It began with a thunderstorm and ended with a DEEEP announcer proclaiming "One Hundred Thooousand Watts Of Two and Four Channel Stereo".  It sounded huge in the car and may have been in quad. 

WKDA-FM Promo.mp3

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The FCC did not approve a quad broadcast standard until long after the demise of quad. Too little, too late. However, SQ and QS recordings could be played over stereo FM and not lose the encoding if the compression was not too heavy. Those systems worked by mixing the four channels onto two channels using phase shifting techniques. The decoder was supposed to be able to extract the four channels by reversing the encoding. For most decoders, it didn't work well. Toward the end of quad, the Audionics Space and Image Composer was developed, and it was able to separate the channels quite well. Later, the Fosgate decoders came out using the same "Tate" system. They were also good. The Sansui Variomatrix QS decoders were known to be very good,and Lafayette made a decent SQ decoder, I am told, though I have never heard one. QS and SQ were different, and while you could use one decoder for the other system, it didn't quite come out right. CD-4 records have supersonic subcarriers, and if played in an FM studio, would come out as a stereo recording. If demodulated, it would yield four discrete channels, but that could not be transmitted over the radio unless encoded in SQ or QS. These are the records that needed special cartridges that could track the subcarriers. A four channel recording from CD-4 is barely distinguishable from a DVD Audio 5.1 setup, if you exclude the obvious lack of record noise on the DVD. It can sound quite good. The four channel system can image the center speaker much as a stereo setup can. I bought my quad setup in the late seventies, and I still maintain it. I have added 5.1 DVD Audio and SACD, and video. This was easy to do since I used separate stereo amplifiers. But sorry, Klipsch, I used JBL speakers. But I do respect your speakers, their reputation is well known. I do say that if you want to be a quaddie, it helps to be an electronic engineer, because the old equipment requires more maintenance than new gear. Even if you do use newer gear, the decoders and demodulators will have to be vintage. That Pioneer receiver dtr20's father has will probably need some capacitors replaced. It would be better to find an older repair tech that remembers quad, I would expect that most of them are retired by now. Good luck.

The Quadfather

Edited by The Quadfather
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