.

.

There are other matrix systems, notably those of Sansui (known as OS) and EV. Similar to these are Fisher's 2+2, Kenwood's QR and Pioneer's Quadralizer.

To clear the air, let's call this group "conventional matrix" or simply "matrix," because the difference is minimal. The SQ system, on the other hand, has an unconventional matrix formula, so that CBS's newly released SQ records may not sound quite right when played through conventional matrix decoders.

Just when the matrix camp is on the brink of getting its housekeeping in order, here comes RCA with the discrete disc, and the battle is on.

The matrix camp is still skeptical, pointing out that discrete 4-channel cannot be broadcast without specific FCC approval, which hasn't been forthcoming.

Reportedly, two methods of multiplexing 4-channel on FM radio have been submitted, one by GE and the other by engineer Lou Dorren, the latter having RCA and Nivico support. Broadcasting an encoded signal, on the other hand, does not require FCC sanction because it goes out over the airwaves as conventional stereo. So, the longer the FCC withholds its sanction of quadrasonic broadcasting, the more entrenched the position of matrix-type 4-channel becomes.

The question you are now asking, no doubt, is "Which system is better?" Significantly, even proponents of matrixed 4-channel concede that four discrete signals are superior.

But these few extra dB of channel separation, they insist, are not worth the added cost of new cartridges, special demodulators and the new equipment that radio stations must buy to go 4-channel.

CBS and the matrix will win, say some, not because the system is superior but because it's more convenient and more commercial.

RCA hopes to counter this by holding the line on record prices -the Quadradisc will cost no more than ordinary stereo, while the SQ matrixed discs by CBS currently have a list price a dollar higher.

To win the record dealer to its side, RCA also promises to avoid "double inventory", gradually converting its entire catalog to 4-channel exclusively (the CBS policy is to issue new releases in a choice of SQ or conventional stereo, expecting dealers to stock both).

Among manufacturers of hardware, RCA claims support from Panasonic, Harman-Kardon, Toshiba, Pioneer, Kenwood and others. It remains to be seen how many will build demodulators into their new 4-channel equipment, in view of the added cost. A matrix-type decoder, on the other hand, is already a design feature of practically all 4-channel gear introduced thus far.

The Nivico demodulator can of course be added to any existing 4-channel set-up that has four discrete channels of amplification.

I've tried it in mine, in order to compare the system with matrix-type quad discs and discrete Q-8 tape cartridges. To make the conversion, I first went through a bit of fuss.

The cables between my turnable and preamp, for example, had to be changed, because Nivico strongly recommends the use of low-capacitance shielded cable - to minimize high-frequency loss in view of the wideband cartridge employed.

Next, the JVC 4DD-10 disc demodulator was connected between turntable and preamp. And in place of my usual cartridge, with its elliptical stylus, I mounted Nivico's special cartridge with Shibata stylus - it has a new-shape tip that huge more of the groove area than either the elliptical or conical type.

From the demodulator to the preamp I connected six cables. Two were for conventional stereo and went to the usual "Mag" inputs.

With this, at the push of a button on the demodulator, you can bypass the unit and play conventional stereo (or matrixed discs, for that matter), using any stereo cartridge.

The Nivico cartridge and Shibata stylus are equally suitable, so there's no need to switch cartridges when switching from one system to the other. The other four cables are for discrete 4-channel signals, which leave the demodulator already equalized and preamplified.

Thus, with a 4-channel receiver or control amplifier, auxiliary inputs are used, rather than phono inputs. I plugged them into the "4-channel tape" inputs on the Sansui QS-1 matrix-type synthesizer.

The demodulator plugs into any available AC outlet, preferably one of those on the back of the receiver chassis. The power, switch, turned on only when playing a Quadradisc, illuminates an indicator lamp. There is a second lamp on the demodulator, labeled "4-channel radar," that lights up only when a 30 kHz carrier signal is detected on the disc. This shows that the circuitry is unscrambling rear-channel information.

The remaining controls on Nivico's demodulator are for adjusting the degree of separation. These are set once, on first installing the cartridge, and need not be touched again unless the cartridge is replaced.

Nivico supplies the 4DD-10 demodulator in an all-inclusive package containing the needed cartridge and stylus plus two Quadradiscs:

Love Story and Other Great Movie Themes played by the JVC Symphonic Orchestra; and Carmen Suite of Bizet, played by the Yomiuri Nippon Symphony Orchestra, conducted by Serge Baudo.

These are the initial releases in JVC's new series of 15 Quadradiscs made in Japan. They will, of course, be followed shortly by RCA Victor's promised Stateside Quadradisc releases.

The sound of these Quadradiscs is, in a word, breathtaking. It bears out the claim that discrete 4-channel has superior separation - to the tune of several dB - especially in the rear channels. Signal-to-noise ratio is also better in the rear channels. And the overall spaciousness and directionality that make surround sound enjoyable to begin with, are measurably and audibly better when there are four discrete channels.

The battle between matrixed quadraphonic records, and RCA's technically more ambitious Quadradisc, promises indeed to be an interesting one in the months ahead. I'll keep you posted.

By WALTER B. RIOS - Off Duty / Europe / July 1972
.

.