Commercial Matrix Quadraphonic Cassettes?

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MidiMagic

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No actual experience myself but the editorial comments in the trade mags (High Fidelity and/or Audio and/or Stereo Review) was that the resulting phase errors from the decoding coupled with this mediums playback anomalies would not make for a stable listening experience.
This affected SQ a lot more than it affected QS.
 

jaybird100

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Ovation advertised cassettes as being matrix.
True. Ovation did release EV- and QS-encoded cassettes, and even 8-track tapes. They also did discrete Q8's. Very few cassette decks could play these cassettes with good results
because of the phase distortion that came from a number of problems, such as misaligned heads. High speed duplication doesn't help, either.
 

tejanoboy

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Care to enlighten us "the uneducated" ?
Azimuth IS ONE aspect of alignment, there is of course also head height. I suspect that if azimuth were off far enough to cause a big phase error, it would also be quite noticeable in the high-frequency losses, considering how slowly cassette tape moves. If the error were, say 10* at 20 kHz, that would only be 2.5* at 5 kHz, better tolerance than the phase shifters in most SQ decoders. SQ being a "phase matrix" (you KNOW Sansui is right!) with rear channels defined by phase shift alone, it may suffer more than QS would, not sure, though. I have recorded QS and "Stereo-4" onto cassette, and decoded it just fine. Mileage varies with deck and tape, I'm sure, I used a tired old Tascam 122 deck with less-than-master-grade cassettes.
Somebody out there with more time than I and a better calculator can no doubt figure how far off in degrees the azimuth must be to produce a given phase error at a given frequency...anybody? (Or cheat and use a tone generator and a vector-scope :>)
TB
 

MidiMagic

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There are actually 5 different parameters to head alignment, although some are fixed on many decks:

1. Azimuth - Adjusting the angle between the line passing through the head gaps and the edge of the tape. Should be 90 degrees. Matches the head gap angle on the recording.

2. Altitude - Adjusting the height of the head to center each head gap on the tape track. Minimizes crosstalk.

3. Perpendicularity - Adjusting the head so the top edge of the head pushes against the tape by the same amount the bottom edge does. Makes sure that all tracks contact the head equally.

4. Skew - Making sure the gaps are in the center of the area on the head the tape contacts (not near one edge of the contact area). Prevents dropouts.

5. Protrusion - For cartridge and cassette decks, making sure the head protrudes enough to use the pressure pads, but no so much that it wears the tape.
 

Disclord

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For SQ broadcasting using 4-track cartridges, the recommendation was to use sum/difference networks for recording - so the SQ stereo signal would be sum and differenced then the two tracks recorded on the cart. When played back, it would be re-combined to standard stereo with no worry about phase errors. This was the recommendation for cassette SQ recording too - the only problem is, it's not compatible for playback without the sum/difference recombination circuit!
 

boojidad

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Earlier in this thread, others have said (or maybe assumed) that Angel SQ releases on vinyl were almost certainly SQ-encoded on cassette because of the existence of only an SQ master. But in a different thread (related to Andre Previn's version of '1812'), I was taught that EMI (including Angel & HMV) vinyl releases could be SQ in one country and plain stereo in another. I have recently been coming across cassettes from overseas (England, France, Germany) of EMI/Angel releases that were SQ in vinyl form, but don't (necessarily) indicate SQ on the cassette package. Assume SQ cassette? Assume stereo? Assume nothing? (Yes, I know how the word "assume" breaks down.) I just wondered if anyone has stumbled on this. I don't have an SQ decoder so I can't "invest & test" on my own.
 

jaybird100

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It's my understanding that the Angel/EMI cassettes of the same recordings released on SQ vinyl here were also SQ-encoded. Problem is, with matrixed cassettes, the quality of the quad decoding can be affected on such things as head alignment and azimuth.
 

EMB

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Which is why any collector of such tapes needs a deck with an adjustable head to keep it aligned. I had a JVC DD-9 that was easy to adjust, and an old Lux not so easy to adjust. Didn't use either for decoding tapes--I bought vinyl for such titles--but it would have worked well, I'm sure.

ED :)
 

oxforddickie

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Earlier in this thread, others have said (or maybe assumed) that Angel SQ releases on vinyl were almost certainly SQ-encoded on cassette because of the existence of only an SQ master. But in a different thread (related to Andre Previn's version of '1812'), I was taught that EMI (including Angel & HMV) vinyl releases could be SQ in one country and plain stereo in another. I have recently been coming across cassettes from overseas (England, France, Germany) of EMI/Angel releases that were SQ in vinyl form, but don't (necessarily) indicate SQ on the cassette package. Assume SQ cassette? Assume stereo? Assume nothing? (Yes, I know how the word "assume" breaks down.) I just wondered if anyone has stumbled on this. I don't have an SQ decoder so I can't "invest & test" on my own.
This only happened in the early days, before EMI publicly went single inventory for classical releases, hence the two different releases. Early SQ albums released in the UK used the pre-fix Q4 before the normal number.

Cassettes were never released with any mention of them being SQ encoded for the obvious issues relating to azumith errors, etc, but they were produced from the same encoded master.
 

jaybird100

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Then, again, commercially recorded cassettes generally sounded terrible. High-speed duplication, combined with very limited dynamic range and poorly applied Dolby B, basically made the format a bad choice for classical music. The SQ records sounded way better.
 

oxforddickie

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In general yes, but Decca cassttes were in general far superiour to EMI's output. One i remember showing what was possible was Caravan's 'Girls Who Grow Plump In The Night'. The cassette became a firm demo favourite in the Hi-Fi shops in Oxford
 

jaybird100

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I'm not saying that ALL commercially recorded cassettes sounded bad, but most did. It's possible Decca used better duplication methods than EMI. But most I heard generally sounded abysmal. My opinion; please, don't everybody bitch me out at once!
 

oxforddickie

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No bitching meant, was just saying that EMI (UK) duplication was really the pits, but as you correctly said, Decca went that bit further to get the best out of the tapes. On another point regarding Decca, UK pressings of their LP's had the labels on both sides match in position as they believed this reduced warpage (!?).

Whether or not it did doesn't matter, it just shows the attatention to detail the company had, until they were taken over, of course, then it all went out the window.
 

oxforddickie

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Very true, forgot that.

Decca did tip their toes into the quad forum in France, with a number of classical releases using QS. I have a few here, and the quality is just as you'd expect from them
 

jaybird100

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Very true, forgot that.

Decca did tip their toes into the quad forum in France, with a number of classical releases using QS. I have a few here, and the quality is just as you'd expect from them
True, but they got into it too late in the game
They should have done some pop or rock as well. They were smart to use QS, though. It sounds better when played in stereo than SQ. Just my opinion...
 

fizzywiggs41

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I sent a letter to Columbia Records back in 1977 asking them.... if any SQ matrix cassettes have been released ?

This from Joe Dash Director Development Columbia Records U.S.A.

" To: Mr. D Galbraith"

-"We are not convinced of the technical capability of most cassette players to handle the difficult task of decoding matrixed cassettes.
Unless there's perfect head alignment the decode will be garbled. However , compare for yourself. Any single inventory SQ release (Masterworks or Broadway Shows) that has a cassette made will have the latter encoded in SQ since the same encoded tape is used to master the LP and the cassette .
Albeit we do not announce this fact."

Sincerely yours,
Joseph F Dash
10/24/77


Edit: typos




Re quad SQ cassettes
 

BrentAudi

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I sent a letter to Columbia Records back in 1977 asking them.... if any SQ matrix cassettes have been released ?

This from Joe Dash Director Development Columbia Records U.S.A.

" To: Mr. D Galbraith"

-"We are not convinced of the technical capability of most cassette players to handle the difficult task of decoding matrixed cassettes.
Unless there's perfect head alignment the decode will be garbled. However , compare for yourself. Any single inventory SQ release (Masterworks or Broadway Shows) that has a cassette made will have the latter encoded in SQ since the same encoded tape is used to master the LP and the cassette .
Albeit we do not announce this fact."

Sincerely yours,
Joseph F Dash
10/24/77


Edit: typos




Re quad SQ cassettes
Thanks for sharing this letter. I have (somewhere) classical issued CBS Cassettes that had the double ring on them just as the Quad Album had. Also, the Reel to Reel issues of Quad Albums I have obviously was the same recording. On the "Introduction to Quadraphonic Sound" the narrator talks about Quadraphonic tapes.
 
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