by Dan Jobin DJobin@kicker.com
The Discrete Quad format as used in the 8-track cartridge was a natural extension of other things going on at that time. It was the early 70’s: the 8-track tape was king, the EPA was making sure that we were not going to buy factory muscle cars, and the home stereo market was enjoying four channel sound.
A lot of us had been working under the hood of our cars, trying to make them faster. Speed shops were a great place to hang out. There was a plethora of goodies available to squeeze another couple of horsepower out of the engine in your pride and joy. Then came the gas crunch and increased insurance rates on hot rods. Since we had a love affair with our cars and tinkering was still going to be done, America turned its attention to the interior of the car. A stereo system had always been an essential part of the picture and it was time to give it even more attention. Instead of boring cylinders, we are boring holes for speakers.
We had been content with conventional two channel music in the car until Discrete Quad came out. All it took was one audition of Edgar Winter’s “Frankenstein” with its wildly panned round-and-round special effects to convince me that four channels were twice as good as two. Forget musical accuracy, forget anything resembling live music, the whirling effects sold me on this new format. It was originally known as just Quad until the British speaker company of the same name complained. Since then many distinct but similar names have been used: Quadraphonic, Quadrophonic, Quadrasonic, and Quadrosonic.
How it works
With stereo 8-tracks you have separate left and right channel information. What’s missing with stereo playback is the ambient information you would get in the form of reflections off the walls of a concert hall. Prior to quad, one attempt to recreate this ambience was making a “difference” channel for the rear speakers. By simply reversing the phase of one of the front channels and adding it to the other front channel the result is a difference channel. This difference channel was sent to the rear speakers to create ambience. While this worked with limited success, someone decided that four discrete channels would be more accurate than stereo with a fabricated rear channel.
To be successful, the Quad format had to be compatible with existing tapes. To build a new and different tape mechanism just for four-channel music would be suicide. Four-track tapes were all but gone, two tracks were but a faded memory, and the Phillips cassette had not yet gained acceptance. As I said, 8 track was king, and 8 track would be the format for Quad. Eight track has four sets of left and right channels. Reading down the tape the tracks go: 1L, 2L, 3L, 4L, 1R, 2R, 3R, 4R. The playback head has two pickups spaced apart so they read 1L and 1R for track one. When you switch to track two it reads 2L and 2R and so on.
To play discrete four-channel tapes the playback head needs four pickups, and the eight tracks on the tape have to be rearranged into two sets of four. Now they read 1LF, 2LF, 1RF, 2RF, 1LR, 2LR, 1RR, 2RR. With this configuration the playback head only has to move down one position and back up again to read the two sets of channels. The disadvantage to this setup is that there are only two available choices of tracks at any one time, while the stereo 8 track has four. This also means that for the same length playing time a Quad cartridge has to have twice as much tape as a stereo cartridge.
To differentiate the Quad cartridge from the stereo cartridge a small groove had to be added to the Quad cartridge. On the Quad compatible players there is an extra switch that senses the small groove and changes the player from stereo mode to Quad. When playing stereo cartridges in a Quad compatible player only the first and third pickups on the playback head are used.
The variety of software available for this “new” discreet four channel cartridge format was truly amazing. The tapes I remember enjoying the most were Edgar Winter’s They Only Come Out at Night, which featured the aforementioned “Frankenstein,” Santana’s Abraxas, which really made the continuous loop tape worthwhile, and Pink Floyd’s Dark Side of the Moon, perfect for sitting in a parked car with the lights off.
In reviewing the old magazine articles of the day, it is obvious that a lot of classical music was being played in four-channel home equipment. The recordings had that concert hall ambiance in the rear channels and on the good home stereos the sound of a live performance was accurately reproduced. In my little world none of that mattered. I was in it for the special effects. Just like when stereo recordings were introduced, there was a lot of playing around being done in the recording studio. And I liked it.
In 1974 I had the honor of seeing Emerson, Lake and Palmer at the Winterland in San Francisco. As part of this new four-channel craze they had four complete speaker systems set up around the room: one on each side of the stage and one on each side of the rear of the room facing forward. It was one of those “you had to be there” situations. Keith Emerson’s keyboard work spun around the room in the greatest display of audio trickery I had ever experienced. This was on their “Welcome back my friends to the show that never ends” tour. Naturally the Quad 8 track three-tape-set with the same name became my new reference. The concert affected me so much that I saw it again the next weekend in Fresno.
During the 70’s I drove a 1965 VW Karmann Ghia. Since I was employed as an installer and bench technician for a car stereo store, having the latest equipment in my car became an obsession. The progression went something like this: underdash Craig 8-track with 4″ Pioneer speakers under the dash. Add another pair of Pioneer 4″ and move them to fabricated kick panels. Remove the Craig 8-track player and replace it with an in-dash AM/FM/8 track with manual tuner. Purchase 12″ Cerwin Vega woofers and mount them behind the rear seat along with a pair of Motorola piezo tweeters. At this time Craig comes out with one of the most important devices ever developed for car stereo: the Powerplay booster. At 12 watts per channel it is a quantum leap ahead of the 4 watts we were previously limited to. Naturally I have to have two Powerplays, one for the front speakers and one for the rear. Now I’m really starting to attract attention while cruising the Main. Just when I think there can’t be anything better than the stereo 8 track playing through two boosters to eight speakers, the Quad players become available.
I opted for a Panasonic CQ-999(?) In-Dash AM/FM/pushbutton/8track/Quad deck. This is absolute 8-track heaven (pun intended). There is no way that I would consider getting rid of this system. The Ghia became an attention magnet down on the strip. Everyone wanted to go cruisin’ with me, just to hear what at that time had to be the baddest stereo in the world, or at least in my town.
Eight tracks were a way of life for me. There was no way that I was going to switch over to that dinky cassette format. I fought the imminent demise of 8 tracks right down to the time Concord came out with their first high performance car cassette players. The writing was on the wall. Here is a format that blows away the frequency response, convenience, and durability of the time honored 8 track. Plus the cassette has rewind capability. I sold out.