Infinity’s first line source

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When Arnie Nudell and his partner John Ulrick founded Infinity Systems in 1969 their first product was a 3-piece loudspeaker called the Servo Statik 1: a pair of rectangular boxes of electrostatic panels and a third, center placed, servo controlled, subwoofer module. This first offering wasn’t all that attractive and by the time it had garnered its first big review in Stereophile, the model—as well as the look—had been upgraded to the 1A shown here.

As Arnie labored over the next generation of loudspeaker John Ulrick worked on a new woofer while their newest partner, Carrie Christie, helped keep the lights on by filling Servo Statik orders. The direction of Infinity’s top model offering was about to change from large surface area panels to what Nudell believed to be the best way to reproduce sound, the line source.

In 1976 Infinity released a new type of speaker called the Quantum Line Source, or QLS. The monicker quantum stemmed from Arnie’s roots as a nuclear physicist (as did the company name, Infinity, with its iconic gold Mobius logo). Here’s a picture of that first Infinity line source.

The QLS was revolutionary. It’s a 4-way system consisting of a 12″ Watkins dual voice coil woofer, a 5″ midbass coupler, 6 convex-dome midrange drivers, 8 magnetic planar tweeters (that would someday morph into Infinity’s classic EMIT series), and one tweeter on the rear. Instead of Ulrick’s servo system of the original Servo-Statik 1s, this new model used instead what I believe was the first commercial application of the Watkins woofer. This unique woofer architecture used dual voice coils to eliminate the typical impedance rise woofers suffer from (when the impedance of a driver rises at resonance its ability to use amplifier power diminishes). The Watkins used a clever filter arrangement that directed the amp’s power to one of the two different impedance coils depending on the frequency, thus smoothing out the impedance curve presented to the amplifier.

More tomorrow.