4 channel cassette idea ( too late )

[fogprez]

I have an awswer to creation of a compatable 4 channel casstette player
I know the cassette is dead and this is to late but I wanted to run it by you to see if anybody thinks it could have flown
some of the proposed ideas were
1. A straight 4 channel tape one track per channel
philips said it was incompatable and would not approve it
2 Dividing the tracks in 2
that would require 8 tracks on that already tiny tape and would be noisey
3. Use the CD4 system
it would be very difficult to build a cassette player with that kind of frequency responce


So My idea uses a combination of 1 and 3
you create sum and difference signals like CD4 but do not modulate them then place the sum signals on channels 1 and 2 and the difference signals on channels 3 and 4
when played on a 4 channel maching they are then run thru a CD4 TYPE decoding to produce the original channels
when played on a stereo system the head reads only the sum signals producing stereo with no loss of information
the same would be true in mono

The only drawback would be the "back side of the tape" wbich would play the difference signals backwards if attemped on a stereo player

 

[JonUrban]

interesting approach.

We had some quad cassette talk here a while back, with some pictures and all:

https://www.quadraphonicquad.com/forums/showthread.php?t=8648

 

[fogprez]

but what did you think of the system that I proposed

 

[JonUrban]

Not sure WHAT I think about it. Like I said, it's an interesting approach, but I wonder how it would work if the tape got stretched or twisted.

 

[ArmyOfQuad]

In theory, it would work just fine. The thing is, I think there are issues that would come up from using a difference signal that you wouldn't get if you just put the 4 channels directly on the tape. So, I see it as sacrificing performance for stereo compatibility. Would it have been worth the tradeoff? That is something that certainly could be debated. I'm one that hates to sacrifice any performance. But, I suppose technically it could work, and it would be interesting to see how that would perform.

 

[fogprez]

it's the same 4-4-4 matrix signal as a CD4 record but without the complications of modulating them on a high frequency carrier and then dividing them up with a frequency divider before re-matrixing them it's just a true 4-4-4 matrix system

 

[QuadMusic]

I'm waiting for one of these to come up on EBay:

 

[Q-Eight]

I don't see what the point of it to be honest. I think the hardware is more important than the software.

Have a cassette deck that can play both 2 and 4 channel cassettes. (Easy enough)

Why would stereo compatibility matter? If you want the 2-channel version, buy it! You want the 4-channel album? Then buy it! As long as your home cassette deck or Qcst player in your car can play either, what's the deal?

Or, at the very least, build the cassette deck with a "Combine" button that will mix the two rear channels into the front to provide stereo.

 

[fogprez]

the problem is that Philips is the owner of the format and they INSIST on compatibility and if it were not for that issue then a decks like the one pictured in the last post would have been produced for the home market not just for studio use .

 

[Quadzilla]

I'm waiting for one of these to come up on EBay:

I have one of those. Nice unit, but one LP side per C90 cassette tape? They run at 3 3/4 IPS (with DBX). Rather use one of my reel decks and a 7 inch tape. Cool looking cassette deck though.

 

[Quadzilla]

the problem is that Philips is the owner of the format and they INSIST on compatibility and if it were not for that issue then a decks like the one pictured in the last post would have been produced for the home market not just for studio use .

They were released after the 25 year Philips patent ran out.

 

[QuadMusic]

I have one of those. Nice unit, but one LP side per C90 cassette tape? They run at 3 3/4 IPS (with DBX). Rather use one of my reel decks and a 7 inch tape. Cool looking cassette deck though.

Practicality almost non-existent, of course, But like you say it looks great - and it'll match my Tascam 34B.

Regards,

Peter

 

[Q-Eight]

Quad Elcaset man, that's where we missed out.

 

[Quadrockasaurus]

For anyone interested - The Astrocom Model 307 Quadraphonic Cassette Deck (1972) - One of the few 70's quadraphonic cassette decks that actually went into production.

 

[timbre4]

OMG!! That is the BEST picture (and color to boot) I've even see of this 1972 Equipment Directory refugee.

If memory serves (3 days a week now) the company was in Oneonta, NY not far from a farm we temporarily bought.

 

[Quadrockasaurus]

One of the better original Quadraphonic cassette decks (....I'm told) is the Neal 140. I'm inclined to believe it seeing that this company built a lot of professional audio stuff.

 

[Quadro-Action]

and don't forget the 4-channel MiniDisc recorder for home-recording as there are Yamaha, Sony and Tascam. Only the special needed Data MiniDisc is too much expensive. One has cost € 16,--. But the sound quality with the ATRAC is satisfying.

Dietrich

 

[Brian McAllister]

I think that Philips would have had some of the same compatibility issues that they had with the discrete 4 track format. Both would play the reverse side of the tape improberly on earlier equipment. They wanted people to be assured that if they purchased a recorded tape, that the user would not be aware of a difference when played on a machine that was made for an earlier tape-recording format.

 

[MidiMagic]

The TASCAM 234 was intended to be a studio multitrack recorder, not a quad system.

The real reason quad got a false start, and then died, is that the manufacturers were mislead. The quad reel to reel recorders that were selling so much faster than all other quad equipment were not going into home quadraphonic systems, but into home recording studios.

TASCAM and Fostek made many "portable studios" in the late 1970s to the present with 4 or 8 track recorders. Their latest digital ones are 24-track.

The Philips 8-track cassette format was realized in the TASCAM 488 and 688 Portastudios, and the TASCAM 238 Syncasette (big brother to the 234). The problem is that they run at 3.75 inches per second (twice the normal cassette speed) and use DBX noise reduction.

The TASCAM Portastudios are great ways to play with discrete quad.

 

[MidiMagic]

Since the Philips patents have expired, they have no more control over the cassette format.