The GS401 Speaker
Winner of the 1978 CES Design and Engineering Excellence Award
There were three significant Gale speakers sold during the Ira Gale era of the company: The GS401A, GS401B, and GS401C. It was known for being power hungry, playing loud, and sounding great. All three used the same internal components. The chrome ended GS401A version is shown above.
What makes the GS401 series special is the ability to provide excellent midrange performance at relatively loud levels. Not too surprisingly, many Quad electrostatic speaker owners also own a set of Gales to use when something with more volume and bass is required.
Launched in April of 1973, the GS401 soon became an industry icon. In one of the classic quotes of audio understatement, the speaker’s “power handling is somewhat above the output of the domestic British amplifier”. Yes, something different had arrived on the scene.
John Borwick wrote in the May 1973 Grammophone issue, “A new exhibitor, Gale Electronics, showed a small speaker system with a sealed enclosure, the GS401. Mr Gale spoke in detail of the merits of his speaker, and with some justification for it has a smooth response, moderate dispersion and fair bass performance.
It uses two 8-inch bass units, so spaced in the enclosure that low frequency harmonics are acoustically cancelled. Not a very sensitive system, it was being driven in one room by an amplifier rated at 140 watts average per channel, and in another case by one which can easily deliver 60 watts average into 4 ohms, the nominal impedance of the speaker. In fact it is recommended for amplifiers rated at ’30 watts or more into 4 ohms’, and costs £89.00.
The chrome ended GS401A was styled by industrial designer Jon Bannenberg. An Australian that had studied at the Sydney Conservatorium of Music, he later went on to design luxury yachts for Larry Ellison, Malcom Forbes, and Adnan Koshoggi. Bannenberg died in 2002.
Only one set has been identified by this group to date.
The GS401C accounts for the majority of the walnut enclosure speakers. It features a curved front grill, and removal of the drivers for repair is somewhat simpler than with the GS401As. The majority of GS401Cs were manufactured in London, with a small quantity made in Carmichael, California after Ira relocated back to the United States (by the same group that owned ESS speakers). Manufacturing location is easily identified by reading the rear input panel.
The very last official Gale GS401 photograph (supplied by Berris Conolly)
Technically the GS401 speaker was specified as infinite baffle enclosure with crossover points at 475 Hz and 5,000 Hz. The enclosure was constructed for three layer high density 18 mm thick chip-board, incorporating internal bracing to eliminate panel resonances.
GS401 frequency response was quoted at 55 Hz to 20 kHz (+/- 3 dB) in the G.E.C. Hirst Research Centre anechoic chamber. 35 Hz to 20 kHz (+/- 5 dB)
Impedance 4-8 ohms. Fuse protected: balance controls for midband and treble. Compact speaker designed for uses as a bookshelf unit or can be placed on Gale speaker stands. Fuse ratings: Main 1.25 x 5 Amp quickblow. HF Fuse: 5 x 20 630 milliAmp quickblow. Suggested Minimum Amplifier Power: 60 Watts. Speaker may be placed vertically or horizontally on stand.
Dimensions: GS401A: 33 cm W x 27 cm D x 60.5 cm L. Weight: 51 lbs. net
GS401C: 33.5 cm W x 29 cm D x 62 cm L Weight: 43 lbs. net
Seven year guarantee. Price each all models (in 1979) was 175 pounds plus VAT (UK), and $495 plus tax (USA). Matching stands were 50 pounds per pair plus VAT (UK) and $50 (USA) and rose the units 18 inches above the floor.
Each GS401 featured two Acoustic Research inspired (see the AR 4 series of speakers) doped woofers (sourced from Chicago Telephone Supply), a Peerless K040 four inch midrange, and a Celestion HF2000 tweeter. Each of these components is now out of production.
CTS Eight Inch Woofer
Typically the surround suspensions on both the woofers will have rotted over time, resulting in an unlistenable experience. The good news is they can be “refoamed” and “doped” by competent speaker repair facilities.
Measured Thiele-Small Parameters
(Kindly provided by Member fanatson)
- Fs=37 Hz
- Re=5.8 Ohms
- Le=1.08 mH
- Mms=33.02 g
- Cms=0.56 mm/N
- Vas=34.26 l
- Rms=1.35 kg/s
Celestion HF2000 Tweeter (as used in the GS401)
The Celestion tweeter cannot be repaired, but occasionally be found on eBay at ever increasing prices! If replacing the tweeters, please note that Celestion provided different mounting hole arrangements to different manufacturers. The standard Gale arrangement used three screws.
Rear view of Celestion HF2000 tweeters
The Peerless K40 midrange shown at left is the key to the GS401 series incredible performance. Original versions used by Gale featured a paper cone as shown, while later versions of the K40 manufactured during the last two decades featured a plastic cone. These cones require refoaming for optimum performance.
The huge three way Gale Crossover (only accessible by removal of the woofer units and fibreglass wadding) is shown at left. Note the two white potentiometers in the upper right corner and the four inductors (black circles with nuts on top). The two smaller black fuse holders can be seen just to the left of the cable harness. The silver cylinders at bottom are capacitors. Two ceramic resistors can be seen in the lower right hand corner. The wirewound potentiometers shown were manufactured by Pollack in Boston, Massachusetts (USA). Some speakers feature large brown plastic bodied types wirewound potentiometers manufactured in the UK by Colvern.
Crossover Schematic Diagram
The GS401 speaker series incorporates separate midrange and tweeter rotary level controls. Whilst these can be used to provide small variations in tonal balance, they are actually provided to compensate for slight variations in specific output of the individual drivers, and enable each speaker to be individually calibrated to a flat response in production. (Tonal balance in the listening room is best set either with the preamplifier tone controls or using a separate graphic or parametric equalizer.)
This is done by setting the controls on a final test to give a level response and then locking the collett knob so that the line corresponds with normal mark. It is important to appreciate that because of this procedure, control will aften be found that are set at one end of their travel, and can thus only be turned one way.
Should a problem be experienced like crackling from a speaker, this can often be traced to a dirty wiper on the potentiometers and can be cured by rotating the potentiometer backwards and forwards a couple of times.
Cleaning and Maintenance
Resistant marks can be removed with a mild metal polish or clear window cleaner. The grille cloth is a polyester material with is resistant to suffing and staining. It can be damaged by excessive heat and if exposed to strong sunlight for long periods of time the dyes used will fade. Dust can be removed from the cloth by careful use of a vacuum cleaner and any marked treated with a barely damp cloth. The use of excessive quantities of water must be avoided as this will damage the cabinets.
The speaker backs are finished with a melamine laminate which, should they become marked, can be cleaned with a damp cloth or a mildly abrasive bath cleaner.
A Fun Bit of History
I worked for Gale from 1974 to 1977. I was 24 when I started and had been working for an advertising photographer in London and needed a change. A friend from college knew the secretary (Lucy) at Gales and was offered a job but didn’t have a work permit and told me about the vacancy. I got the job after a quick interview with David Lythe (later of Volt Speakers) and was put onto the production line building the speakers. It was a fun time, being in the middle of Mayfair and reputedly being the only factory in the vicinity. Bruton Place was a great road just of Berkeley Square where the nightingale sang, Lol.
There was I first met Ian Dampney and Nigel Hobden. Donald Sinclair, a whiskey drinking Scott was the speaker manager and many an evening was spent in one of the Mayfair pubs after work. he taught me to drink pints of bitter with a whiskey chaser. The other guys I remember making the speakers were Mo, Dennis and an Indian Guy who’s surname was Patel but I forget his first name. Peter Balkan was the little guy who tested each speaker we made in the anechoic chamber, he was fun when he was fun, but had a wicked temper when he wasn’t. Ray was the salesman and had an E-Type Jag I remember. There were three African ladies upstairs who coated the speaker cones, I forget their names but one was a genuine princess.
In time I got promoted upstairs to build the decks and the deck control units which was a bit quieter. I had a dust free chamber to work in and i remember building the control units and calibrating the speeds of the deck using a scope to tweak the crystal which controlled it.
Eventually I remember we were joined by John Curl who was designing the amp. He had worked for Mark Levinson before that I believe and our amp was going to be the best. He was put up in an expensive Mayfair hotel for the duration of his stay in London. Typical Ira spending. That amp ended up in bits on the work top. I remember Ray Cooper visiting the workshop and talking to him. I think he is still a friend of Nigel. I also remember looking out of the upstairs window when Oscar Peterson visited, and the guy from Yes.
Ian and Nigel saw the end coming with Gale’s as Ira tried to expand, I remember he was going to buy EMI at one point. The started up a Model making business and took me with them and I worked for them for 21 years until the made me redundant! Lol. I’m back in photography now.
Did you know that Hi Fi and photography have always been closely linked, don’t ask me why.
I remember when Gale went broke and we got paid out in the street in Bruton Place (now a Pizza Express). Then Donald Wong bought the company and a skeleton crew moved to Kensal Rise. That lasted a couple of years I think and I worked for the model making company there. Eventually Donald took production elsewhere and I think dropped the large speakers and went for smaller ones.
I had a silver pair of stands and actually sprayed them black. I think I threw them away eventually, sorry folks. I still have the black and chromes though and they still work ok, the surrounds are probably falling apart but I don’t thrash them. I run them from a Quad 303 and the 100W ‘dumping’ amp (Quad 405) still.
I used to do the HiFi shows with Ray, they were fun playing Oxygen by Jean Michael Jarre, Yellow Brick Road, and The Dark Side of the Moon at high volumes to HiFi ‘heads’.
I love the pictures that you have on this site. Have you got the Playboy Mag one’s? (See the Turntable Page for the Playboy spread- John) Or was it another men’s mag I forget, I have it somewhere. There was one add of the B&Chrome taken on a stand in a garden with a cat on it. I think they only used it once, have you seen that one? It was my garden, my cat and I took the picture!”
GS401 as “The Legendary Amp Killer”
The GS401 was a tough load for many power amplifiers, as alluded to in the advertisement well above (If your system has less than 40 watts per channel) and in a more modern impedance measurement graph directly above. Due to the dual eight inch woofers being wired in parallel, the load impedance at low frequencies is between 3 and 4 ohms, similar to the Quad ESL 57 (they both share a great midrange too).
The low frequency impedance drove many 1970’s amplifiers crazy, forcing them to run outside of their transistor’s safe operating area. This led many to the conclusion that amplifiers that could safely drive the Quad could also safely drive the Gale, which was true up to a point, but…
In some ways the Quad 303 amplifier may have been a nemesis to the Gale GS401. While the Quad was “unconditionably stable into any load” and could handle 3.5 ohms at low frequencies, one had to remember it maxed out at about 40 watts into an eight ohm load. This was by design, intended to keep your tweeter panels from arcing on your electrostatic speakers. But it wasn’t enough power to make the Gales strut their stuff. Thus the need for big American amplifier iron!
Thus the two protection fuses (one in earlier models), intended to blow prior to the crossover self destructing which was known to happen in studio use where high SPL’s are the norm (click on the factory comments to the left). The next generation Gale 402 crossover was improved and physically vented to the outside atmosphere for this very reason.
When one reads Gale’s contemporary literature, there’s a graph of electrical impedance from 50 Hz to 20 kHz that is clearly wrong. It states that the load is 8 ohms at 40 Hz, 4 ohms at 100 Hz, 10.5 ohms at 400 Hz, 4.5 ohms at 2 kHz, and 3.4 ohms at 5 kHz. If only it really was!
There was a good reason to couple the big American SAE amplifier to the GS401 series! No wonder they advertised together.
To Rebuild or Not to Rebuild?
Many of our members ask whether or not rebuilding their speakers is worth the effort it takes to reinvigorate them. The short answer is yes, as is the middle and long answer! After the drivers have been refoamed, perhaps a tweeter replaced, maybe some of the crossover reworked, a little Simichrome polish on the ends, and you will end up with something truly special, easily outclassing anything a big box high fi stores sells at any price. Yes, they get noticed too… especially on the chrome stands- now available new from member DS.
The GS401 makes a perfect compliment for Quad Electrostatic owners. Many in our group use Quads for low level high resolution listening and the Gales to rock out or listen to the 1812 cannon shots without fear of panel arcing. The resolution is not quite as good as the Quads but it is not hugely different, and but they play much louder without fatigue. They will provide you with hundreds of hours of listening enjoyment.
Why? It’s the midrange! Gale went to a significant amount of effort to source both a superb midrange unit from Peerless and correctly design a crossover network for optimal human interface. The Peerless K040 has a remarkable bandwidth, which was enhanced by its integral metal enclosure designed to maximize its low frequency extension. Other manufacturers took notice as well (including IMF) and included it in their designs. It remained in production for close to forty years and is still sadly missed today in the speaker design world!
The Carmichael Crossover
(USA built- compare it to the UK printed circuit board above)
(black with brown backing)
Gale selected crossover points for the GS401 around the Peerless midrange’s frequency extensions at 475 Hz and 5 kHz. Roughly ninety-five percent of all commercial speakers have a crossover point right in the middle of our critical listening range (500 Hz to 3 kHz), an issue Gale scrupulously avoided in his design. This bandwidth determines both speech and music intelligibility and is critical for high resolution sound reproduction. Note the huge magnet structure, the integral acoustical damping, and magnetic field barrier created by the metal enclosure- years ahead of their time.
The only obvious contemporary competitor to the Peerless midrange was the KEF B110 midrange. While the five inch driver does have a lower frequency cutoff, it has an annoying spike around 1 kHz (only one of the reasons the LS3/5A has such a complex crossover) and high frequency performance only extends to 3.5 kHz. Obviously not good enough for Gale!
Gale carefully and correctly chose his speaker components. The GS401 is truly a classic well worth the effort. Once you’re done, you will end up smiling!
Member Sean has provided a helpful series of hints at:
The following was submitted as a comment by a chap called Peter Balcon on my GS401A refurbishing article :
“I commend you for your efforts in rebuilding these speakers! That fibreglass stuffing was a nightmare to work with! We finally installed large specialised ‘air-conditioning’ units that electrostatically removed particles of fibreglass from the air in the factory where they were stuffed. I had very long hair in those days (it was the 70s!), and I had a persistent rash down my back from where particles got into my hair and then dropped down my neck. Not nice. I wonder if any of the other guys that worked there have had as many lung problems as I experienced in recent years.
We also coated the cone and foam surrounds with a diluted PVA adhesive manufactured by Moyen to protect the surround and critically damp the assembly. Moyen made a huge variety of materials for the speaker industry many years ago; I don’t know anything of their current involvement.
The polyester cloth was originally welded to the T-strip using a RF welder – a very nasty bit of kit, capable of removing your fingerprints if you came in contact with the aerial! The T sections were then hammered into the slots on the back of the speakers to nicely stretch the cloth over the speaker. There were big globs of hot melt glue under the end caps to prevent any rattling.
I worked with Gale between 1975 and 1979 at the Mayfair factory, and briefly with DW Labs’ reincarnation of Gale in North London in 1980, testing and calibrating each speaker made. The most fun job I every had!”
How to Bypass The Potentiometers
(a quick diagram from member DS)
Well Respected Speaker Rebuilders Familiar with GaleDavid Smith (complete speakers as new, chrome stands, parts, repairs and rebuilds to order) UK firstname.lastname@example.org Wilmslow Audio (non-original replacement parts and repairs including grille cloth) UK http://www.wilmslow-audio.co.uk/ SpeakerCity USA(repair) USA http://www.speakercity.com/Merchant2/merchant.mvc? Orange County Speaker Repair (parts and repair) USA http://www.speakerrepair.com/Merchant2/merchant.mvc Speakerworks http://www.speakerworks.com.au 137 Concord Road North Strathfield 2137 N.S.W. Australia Phone (+612) 97465754 Greg at www.speaker-repairs.co.uk supplies full refoam kits for 401/402/301 Reproduction grillecloth is available. All enquiries and orders to Sid Chaplin at (recommended by DS): Email: sidney (at) tradradgrilles.freeserve.co.uk
Telephone: 01702 473740 (UK) 011 44 1702 473740 (from USA)
Post – 43 Lime Avenue, Leigh-On-Sea, Essex, SS9 3PA, England