:: the austin hifi blog ::: Richard Burwen and his 20,000-watt hifi system

(This is an archived post from our old blog.)

click image to enlarge

(photo from: Audio Magazine/scrounge.org)

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(photo from Richard Burwen's website.)

Okay, this is pretty fascinating stuff.

I realize it's pretty far off-topic for our single driver speaker blog, but anyway...

Who is Richard Burwen?

Here's his bio.

Here's just a small blurb from his bio in case you skipped the link:

Dick got into a lot of really interesting projects. Among the more challenging projects were ultra-low drift chopper-stabilized DC data amplifiers, IC multipliers and function generators, magnetometers, and low-noise switching power amplifiers. He designed circuitry of the first transistorized blood cell counter, a seizure detector for epilepsy, photoelectric relays, high resolution CRT displays, early projection color TV, a military satellite spin detector, and magnetometers for ground use and aircraft. His spacecraft magnetometer circuits successfully measured the magnetic field of the moon from orbit.

The article about Richard Burwen's 20,000-watt hifi system comes from Wayne's Speaker Building Page. The article is excerpted from Audio magazine, April, 1976. pp. 44-56 and was written by Richard S. Burwen.

click image to enlarge

(photo from: Audio Magazine/scrounge.org)

Here's a blurb about Richard's 20,000-watt hifi system:

Each of the five speaker horns is 13 ft. deep and has about 64 sq. ft. of mouth area. [i.e. 8 foot x 8 foot] The horns are conical, in preference to exponential, in order to produce a gradual low frequency rolloff, instead of a sharp cutoff. As it turned out, due to reinforcement from the room, the average low frequency response on one third octave bands is flat down to 16 Hz without equalization.

Each speaker horn contains 30 Cerwin-Vega tweeters, a midrange horn with two JBL 2440 drivers, and two Empire 16 in. woofers. In addition, the left-front and right-front horns have two 24 in. Cerwin-Vega woofers, mounted on the doors. These woofers are equipped with feedback windings to linearize their acoustic output over their range.

and...

To drive these speakers there are a total of 17 Phase Linear 400 amplifiers [200 watts RMS/channel @ 8 ohms].... Each woofer, midrange horn, and set of 9 or 12 tweeters is driven from one 200 watt amplifier channel. With the electronic crossover at 50, 400 and 5,000 Hz ahead of the amplifier, the speakers can produce the same sound level that would be produced by a single 20,000 watt amplifier.... The crossover filters utilize UM201 modules to produce 6-, 12-, 18-, and 30-db/octave cutoffs for the various drivers. In addition, the crossover provides equalization to lat acoustic response.