Beveridge 2SW loudspeaker system Specifications

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Description: Electrostatic line-source loudspeaker with integral tube amplifier. Drive-units: three 24"-high transducers, and three 24"-high lenses per speaker. Frequency response: 40Hz–15kHz ±2dB over 180°. Lowest useable output: 35Hz. Maximum spl in-room circa 110dB.
Dimensions: 78" H by 24" W wide by 16" D.
Price: $6000/pair (1978), $7000/pair (1979).
Manufacturer: Harold Beveridge Inc., Santa Barbara, CA 93103 (1978). Web:

Harold Beveridge Inc.

Sal1950's picture

I would be very curious as to how many, if any, of these high tech, high voltage power supply speakers still exist in good operating condition. As I remember from years ago there were reliability issues with both the Beveridge Stats and the Plasmatronics in use when they were new. Both the electronics and drivers were problem-some.
On the other hand I'm sure you can find plenty of vintage LS3/5a's still singing beautifully everywhere.

cgh's picture

I grew up listening to the big cylindrical Beveridge speakers (I think they were the 2a's). My friend's father owned them and I practically lived at their house. This was in the mid eighties through early 90's. My recollection was John Dahlquist modified some aspect of the speaker, but they played music all day and all night. From listening to the New Afternoon Show on WNYU, or the original WLIRR, to late night vinyl sessions. What went after maybe 2 decades were the stators. There was a woofer that fired from the top. The paper wore with age too. Great speaker for the time. Great memories.

The other speakers in the house were the Dahlquist phased array DQ-10. These were the speakers that planted the seed for me.

Russell Dawkins's picture

It is worth noting that Roger Modjeski (mentioned as the young amplifier designer)is still in business and active:

Ronald Koh - SG's picture

Hoping this will make some good sense.

1. The only great and all rounder sounding one is the Quad63 by Peter Walker. As its high & mid frequencies radiates out in concentric circles to give a coherent musical sound image and stage within its design parameter limits to enjoy. However, the caveat is its high charging 2,000(2k) volts that is problematic in high humidity climates like here in Singapore. Of course their latest double stack models are better. But if one wants deep low rhythmic bass below their lower limits, a really good compatible sub-woofer is a real necessity for real world pitching, rolling, grunting, groaning, even sighing, good slamming etc bass for bowed & plugged double bass and cello, all types of bass drums etc.

2. And with 180 degrees dispersion, the caveat is also the 2 crossover points between high & mid and mid & low in any given room to manage its eigentones vibrations & reflections within it audio band. Very complex. And with 2 bass boxes, physical integration is a tough nut to crack acoustically. Like with Infinity's IRS and Genesis' high-end dipole ribbon speakers with separate servo driven woofer columns just as high as their ribbon panels. Wrongly positioned and they can sound over-bright and unbearably unmusical. Even with Infinity's single speaker with servo bass and 4-way dipole ribbons on top via passive crossover networks, it already tough getting them to really sing musically.

3. Thus before buying a pair of loudspeakers, especially of costly hi-end variety, one must get a well experienced person to assess what type of speaker to avoid in one's listening room. By factoring in furnitures etc in addition to its shape, size and speaker placement limitation. As well as WAF too! I've been fortunate to be able to do what I need without WAF problems!