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Airwaves: April 16, 2010

Quadraphonic ... In Stereo

Years ago, back when I was old enough to spend my own money but not old enough to drive, I went with my friend Dean and his family to Wallach’s Music City in Torrance to check out their prices on stereos. This was clearance time for the chain ... they were shutting down. And I happily walked out of the store with a brand-new Marantz receiver for only $99.

On the back of the receiver was an FM quadrial output. The idea was that you could connect this output to a special decoder and a second amplifier and hear actual quadraphonic FM sound. I don’t think Marantz ever made any of the decoders, but they did make quadraphonic receivers, giving a full surround-sound experience with four speakers years before anyone spoke of surround sound for home theaters.

It didn’t catch on, of course, and soon the idea became just another footnote in broadcast history. Or perhaps it was just too far ahead of its time.

In a weird, twisted and warped combination of technologies that ultimately and perhaps unfortunately didn’t catch on ... and one that did, a little AM station in Coralville, Iowa decided to celebrate the 40th anniversary of quadraphonic sound via AM stereo.

Let that sink in for a minute. AM, that 90-year old technology that some people continue to write off, was used last month for a broadcast of quadraphonic sound. Successfully.

Here’s how it worked. The original quadraphonic records were encoded into Dolby Pro-Logic II recordings, then played through the analog AM stereo (C-QUAM, for you purists) system and sent over the airwaves. Listeners with AM stereo radios could send the audio through their home theater system to decode the Pro-Logic signal and hear the broadcast in full-dimension surround-sound.

This would be the first time that quad records were played on the air since the 1970s, and certainly the first time surround-sound was broadcast via AM radio. The broadcast was on February 26th, but it is still available on the internet in case you want to hear it through your computer.

Of course you don’t get the full effect of hearing this on full-fidelity AM, but you can at least experience some interesting effects if you have a surround sound system on your computer or play the recording through your home theater. It’s quite impressive, actually. The fact that it was done with AM is historic.

Point your browsers to and scroll down to Robb Radio 27: February 26, 2010 ... “History in the Making.” The music mix is interesting, and I think you’ll enjoy it. As an interesting aside, KCJJ ( broadcasts KROQ’s (106.7 FM) Kevin and Bean show daily from 1 to 5 PM Central. Kevin and bean. In AM stereo. In Iowa. Amazing.


Some interesting suggestions regarding music on the internet that evolved from the discussion of Ontario’s KSPA (1510 AM) dropping music for talk.

But the best came from Liz Myers of Los Alamitos, who suggested, one I had never heard of. “I like the variety to fit my moods, and the choices as to composers, etc.” she said. She’s right: the variety is amazing. Still not local radio, but what’s that any more?


Copyright © 2010 Richard Wagoner and Los Angeles Newspaper Group.

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