ESS speakers
Encyclopedia
ESS was a company that was based in Sacramento, California. Their original speaker designs were a hybrid of conventional woofers, passive radiators, and electrostatic tweeters in bookshelf and tower configurations. They were one of the only manufacturers of Dr. Oscar Heil's Patented Air Motion Transformer
(AMT) speakers.
bass cabinet driven by the racetrack shaped KEF solid woofer. The transmission line bass cabinet unloaded onto the floor, resulting in bass output astonishingly deep and strong with crystalline clear highs from the functionally mass-less electrostaic tweeters. were transparent and "airy." These speakers could easily absorb the full output of the high powered 350-Watt-RMS Per Channel audio amplifiers of the day like the Phase Linear 700 and allow the listener to actually feel and hear it. The TransStatic-1 was approximately 48" tall with a 14"x24" footprint. The TransStatic 1 sold for $999/pair in Walnut and $1,399/pair in Brazilian Rosewood in 1972 (That's $4,507/$6,312 in 2009 dollars).
There was a bookshelf variant with a KEF woofer, fewer tweeters and no transmission line. There was also a TransStatic-2 which was in essence four TransStatic-1 speakers, stacked two to a side with the top half flipped. This resulted in woofer cabinet exit points being at opposite sides of the stack.
ESS bought patent rights to the Heil Air Motion Transformer (AMT) and their first product was the ESS AMT-1. Looking like a truncated, four sided pyramid; the system combined the AMT driver with a 10 inch woofer and bass port. Several variations followed including the AMT-1a which replaced the 10" woofer with a 12" woofer and a passive radiator, giving the product better bass response characteristics. The AMT Tower was a speaker design with 1 AMT and a woofer and line transmission. The AMT 3, also called Rock Monitor; a design with 1 AMT, a 6.5 inch mid-range and two 10 inch woofers.
At the end of the 70s, ESS and Dr. Heil introduced the ESS Transar using one AMT for the high frequencies and one for low frequencies.
Until 2006 it was still possible to get ESS speakers from Sacramento on demand.
The most common use for the AMT driver in consumer electronics today is as a midrange-tweeter or tweeter in high-end multi-driver speakers, sometimes paired with horns, or in the case of Precide's speaker products, with an upward-firing woofer driver.
There are a couple of companies producing Heil AMTs: Precide (Switzerland) who calls their version the AVT (Air Velocity Transformer), ELAC (Germany) who calls their version of the transducer JET or PI, ADAM (Germany), FAL (Japan), ETON. In Germany it is also possible to get ESS speakers (new designs or classic ones) as well as the ESS AMT drivers (e.g., Great Heil).
Air Motion Transformer
The Air Motion Transformer is a loudspeaker mechanism, or audio transducer, invented by Dr. Oskar Heil. It operates on a different principle than both electrodynamic and electrostatic speaker drivers...
(AMT) speakers.
Consumer Products
The first ESS flagship product was the ESS TransStatic-1. It used a design with electrostatic tweeters, an infinite baffle mid-range in a floor-loaded Transmission LineTransmission line
In communications and electronic engineering, a transmission line is a specialized cable designed to carry alternating current of radio frequency, that is, currents with a frequency high enough that its wave nature must be taken into account...
bass cabinet driven by the racetrack shaped KEF solid woofer. The transmission line bass cabinet unloaded onto the floor, resulting in bass output astonishingly deep and strong with crystalline clear highs from the functionally mass-less electrostaic tweeters. were transparent and "airy." These speakers could easily absorb the full output of the high powered 350-Watt-RMS Per Channel audio amplifiers of the day like the Phase Linear 700 and allow the listener to actually feel and hear it. The TransStatic-1 was approximately 48" tall with a 14"x24" footprint. The TransStatic 1 sold for $999/pair in Walnut and $1,399/pair in Brazilian Rosewood in 1972 (That's $4,507/$6,312 in 2009 dollars).
There was a bookshelf variant with a KEF woofer, fewer tweeters and no transmission line. There was also a TransStatic-2 which was in essence four TransStatic-1 speakers, stacked two to a side with the top half flipped. This resulted in woofer cabinet exit points being at opposite sides of the stack.
ESS bought patent rights to the Heil Air Motion Transformer (AMT) and their first product was the ESS AMT-1. Looking like a truncated, four sided pyramid; the system combined the AMT driver with a 10 inch woofer and bass port. Several variations followed including the AMT-1a which replaced the 10" woofer with a 12" woofer and a passive radiator, giving the product better bass response characteristics. The AMT Tower was a speaker design with 1 AMT and a woofer and line transmission. The AMT 3, also called Rock Monitor; a design with 1 AMT, a 6.5 inch mid-range and two 10 inch woofers.
At the end of the 70s, ESS and Dr. Heil introduced the ESS Transar using one AMT for the high frequencies and one for low frequencies.
Until 2006 it was still possible to get ESS speakers from Sacramento on demand.
The most common use for the AMT driver in consumer electronics today is as a midrange-tweeter or tweeter in high-end multi-driver speakers, sometimes paired with horns, or in the case of Precide's speaker products, with an upward-firing woofer driver.
There are a couple of companies producing Heil AMTs: Precide (Switzerland) who calls their version the AVT (Air Velocity Transformer), ELAC (Germany) who calls their version of the transducer JET or PI, ADAM (Germany), FAL (Japan), ETON. In Germany it is also possible to get ESS speakers (new designs or classic ones) as well as the ESS AMT drivers (e.g., Great Heil).