Techron TEF 20
A DSP measurement platform that turned acoustic analysis into something you could run from a desktop computer.
Overview
The TEF 20 is the measurement platform at the center of Techron's TEF line. It is a DSP-based analyzer that, paired with the company's Sound Lab software, runs on a Macintosh or IBM-compatible computer. Techron began shipping the TEF 20 and Sound Lab software together, as a complete acoustic measurement package rather than a rack of standalone instruments. According to Mix (1990, p.19), the system combined the TEF 20 measurement platform with user-friendly software for Macintosh or IBM-compatible computers. It was an acoustic measurement tool that connected to a computer the user already owned.
The TEF name had a reputation by the time the 20 arrived, and Techron's advertising leaned hard on it. A Mix (1991, p.57) ad for the "new TEF System 20" promised "legendary TEF technology at one-third the original cost," and listed cluster alignment, speech intelligibility, delay-line setting, and noise measurements among the capabilities. That's marketing copy, not an independent verdict. Still, a manufacturer only claims one-third the cost when the name already sells.
The hardware is a DSP-based measurement instrument. Techron's documentation describes it as a platform that works with software modules, not a self-contained box. The Sound Lab RTA software is the clearest example. It was designed for audio professionals and performs Real Time Analysis on either the TEF 20 or the TEF 20HI, with measurements taken at 1, 1/2, 1/3, 1/6, and even 1/12 octave bands. Collected data can be viewed in 3, 6, or 12 dB per division increments, and six sets of non-volatile memory are provided for storage. Once stored, data can be manipulated to obtain overlays or compared against a standard using a difference mode. The RTA module works alongside the TEF 20's other capabilities. One box, a growing set of software tools, and a computer handling the interface.
The TEF 20HI is the sibling worth knowing about. It has the same powers as the TEF 20 but adds a high-speed interface that lets the unit work as a digital audio recorder. It also lets third-party software programs use the TEF 20 DSP chip to control the entire system. That interface opens up functions not usually associated with TEF gear: a top-notch digital oscilloscope, a real-time analyzer, a filter generating unit, and a data capture and display/analysis device.
By early 1993, Techron was delivering AcoustaEQ MS-DOS software for the TEF 20 analyzer. Techron was a division of Crown International, based in Elkhart, Indiana. Per Mix (1993, p.108), AcoustaEQ simultaneously gathers and displays a sound system's equalized and unequalized frequency response, along with the inverse of the equalization curve.
The TEF 20's introduction also had a secondary effect on the market. As noted in Recording Engineer, Techron's launch of the TEF 20 meant used machines would be coming onto the market, and Experienced Audio had set itself up as a clearing house for Techron's used equipment. The measurement platform had been expensive enough to keep out of smaller shops, so those secondhand units were the first realistic path to ownership for a lot of engineers.
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