Naim electrostatic

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Information

Miscellaneous information

Christain Steingruber provided the following information:

The Naim Audio FL 1 was a prototype built around 1987, when the marriage between Naim and Linn came to an end.

The designer was Guy Lamotte, a Frenchman, who also invented the series 5 modification of the Naim amps and some Naim tuners. He wanted to build an ESL as rigid as possible. As admirer of the Quad ESL 57 he used similar dimensions. The FL1 actually looks like a battleship version of the fragile 57.

Some prototypes of the FL1 were built and thought as very promising. Hifi-Review could hear the FL 1 in the Salisbury factory and spoke very enthusiastic about the demonstration (January/February 1987 issue). Hifi-Answers also reported about the FL1 and that it would be available within short time.

Unfortunately designer Lamotte was not too happy in England and left both country and company, without finalizing the speaker. According to Mark Tucker the costs had become very high and the company decided to stop the ESL project and to build conventional speakers instead.

Reviews

The well respected UK audio reviewer Noel Keywood (Hifi-Review, 1988)(provided by Christian Steingruber)

"Onwards to 1985 and-nursing reservations-I asked Quad if I could listen to their successors, the ESL 63. It was the start of a long on/off relationship whcih has been going until now. The 63s came into the listening room for a few hours and then went out. I wanted more volume, stronger dynamics and deeper bass. But after listening to some cones-in-boxes for a few hours I realised I could now clearly hear their colorations, distortions, incoherence and poor transient respones. Re-enter the Quads ! The situation eneded in a stablemate, with the Quads holding theoretical supremacy whilst the boxes the boxes were small, went loud and had dydnamics.

(Naim designer) Guy Lamotte suffered the same experience. Faced with the Quads he also felt they represented the way forward in a way that cone loudpseakers could not hope to. But equally they weren't perfect and the trade offs were agonising. His solution was to design an electrostatic loudspeaker that tackeld the problems directly. The Naim electrostatic is back loaded to achieve good bass and plays loud too, so I'm told."
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The following is the text of an article Christain Steingruber provided:

Electrostatic Attraction

We visit Naim Audio and speak to Guy Lamotte about his exciting new FL1 elctrostatic speaker

"A speaker with as few compromises as possible" was the answer I was given when I asked Guy Lamotte what the design brief was for the forthcoming Naim electrostatic loudspeaker.

This is quite uncommon in British hi-fi manufacturing: normally a designer is given a budget and a set of design ideals- if the two are incompatible then it's compromise time where performance is concerned. The cost is always the factor which limits the speaker's potential. With Naim's FL1 the situation was reversed -"Build it" they told Guy, "and we'll work out the price when you're finished". But this is leaving out half the story -how the FL1 became a commercial proposition having started life as a kitchen table project at the home of Monsieur La matte. Guy explained that he was becoming increasingly frustrated with the performance of his system at home. When he was listening to his 'six-pack' Isobarik system he yearned for some of the attributes of his Quad ESL speakers. Conversely, when he changed over to the Quads there were aspects of the Isobariks that he missed. Fed up with constantly having to rearrange his system according to his mood he decided that he needed to find a loudspeaker that possessed a combination of the finer qualities of the two very dissimilar speakers he was currently using nothing that was commercially available came close to satisfying him so there was only one course of action left open - to build his own !

At the time he started on this seemingly impossible task Naim Audio didn't want to give top priority to Guy's project: the Linn/Naim relationship was, superficially, still cordial and Naim didn't want to rock the boat. Guy decided to go it alone, turning his kitchen into a makeshift laboratory come workshop. After the 'split' between the two companies the 'political' situation altered and it became expedient to transfer operations to Naim's Southampton Road headquarters. Since work began in March last year the design has advanced considerably and the Editor and I were invited to the factory in October to have a look at, and a listen to, an early prototype pair.

The FL1 is an interesting three way hybrid - the bass and midrange units are of Guy's own design and manufacture and are electrostatic cells. Higher frequencies are handled by a ribbon driver. Presenting a frontal area of comparable dimensions to a Quad unit the FL1 comprises two cells to handle bass frequencies (up to 325Hz) which flank a single mid range panel. Above this configuration in the center of the speaker is the ribbon driver which operates from 5.6kHz upwards. Below the drivers, inside the integral stand, is a box which houses the passive crossover components and the transformers and electronics for the electrostatic cells.

Normally mention of the word 'electrostatic' summons up certain preconceptions in the speaker which will not go loud, has 'beaming' treble dispersion, is prone to arcing and self destruction if driven too hard, is particularly room and atmosphere sensitive, and - probably their major failing - has no bass. None of these problems afflict the FL1 you'll no doubt be surprised and pleased to hear. Furthermore, they retain all the attractive qualities that make people buy conventional electrostatics in spite of all their failings.

Guy has overcome the majority of these problems by a clever and innovative approach to the design of the electrostatic cells. Basically, these comprise three 5 micron thick Mylar panels and two alloy electrodes housed in a rigid aluminum frame. The panel sandwiched between the electrodes is coated with a semi-conductive material to carry the high voltage charge necessary for the unit's operation. Signal applied to the electrodes causes the center diaphragm to move in a push-pull fashion and at the front and back of the cell the other panels mirror that movement by virtue of the fact that the unit is sealed and airtight. So the outer panels are 'driven' by the air that the center panel is trying to displace. Guy has also taken pains to carefully insulate the parts of the driver that carry any voltage and has allowed the inner panel as much room to move as possible. This has given the cells distinct advantages over other electrostatics. Not the, least of these is that the FL1 is extremely robust.

Quad ESL owners who hove inched the volume up too far may have experienced arcing within the drivers which causes perforation of the diaphragms. This will not be a problem with the Naim design. Guy has driven his cells so hard that the Mylar diaphragm has come into contact with the electrode and stayed there for half a day without any damage resulting! The bass and mid range cells are damped and acoustically loaded which, as well as optimizing their response characteristics, also means that the FL1 is not overly sensitive to room placement. They should be far mare consistent and easier to site than a fully 'open back' type speaker -the only stipulation that Guy makes is that one shouldn't place them closer than about one meter to a rear wall. Another problem with 'conventional' electrostatics is their bass response, or rather their lack of it. I asked Guy how low the cells would go. 'Down as far as the transformer will allow. In the final design we'll start to roll of the response around 22Hz.

This question brought an interesting anecdote to light. Whilst working in his lab, Guy left one of the cells with a high level, very low frequency signal running through it in the adjoining room. After a while he began to suffer from a rather bad stomach ache which he couldn't account for. When he cut the signal to the cell he was testing his stomach pains disappeared.

We heard the speakers being driven in an active 'tri-amp' mode but the production models will be suitable for both active and passive applications with all of Naim's range of amplifiers. This will mean that someone who owns a single 40watt NAP110 will be able to use it to drive a pair of FL1's if he so wishes. If he then upgrades to an NAP25O or a pair of the mono NAP135's no changes will need to be made to the speaker. Should he later decide to 'go active' using either three 250's or six 135's all that is required is to add an external NAXO crossover and to snip the wires to the speakers internal crossover (I imagine that Naim would be much happier if they or one of their dealers performed this latter task- some parts of the FL1 carry 4000 volts!). In common with all electrostatics the load is quite reactive; impedance peaks at 35Ohms at low frequencies falling to an average 12ohms, but falling as frequency increases. It will not be terribly easy to drive but all Naim amplifiers will be able to drive them. It is planned that the speakers will be manufactured in-house. This will enable them to stringently monitor production and quality control. I asked Guy if this would mean considerable expense in providing production facilities. He replied that all that was needed in addition to what they already have is a dust-free room in which the electrostatic cells can be assembled. It is extremely important that the inside of the cells is kept free from foreign matter if the unit is to meet and maintain its specification.

Electrostatics can often be adversely affected by the atmosphere in the environment in which they are used. Humidity, temperature etc. take their toll with the result that the speakers can sound good on one day and bad the next -or their performance can vary if it rains or is very hot. Guy's experiments so far have shown that the FL1 is not susceptible to this kind of variation. As long as the speaker is fully 'charged up' (if the speaker is not left an all the time all that is needed is about a half hour warm-up period to bring it to readiness) its performance should be consistent.

So, what did they sound like, I hear you cry. The short answer to that is 'rather bloody amazing' - and do remember that we didn't hear them under anything like ideal circumstances. Program material was provided by disc and radio sources and the latter served as a fine introduction to the incredible naturalness of these speakers. We listened to part of a play that was being broadcast where the action took place in a canteen. Behind the actors the special effects men were having a field day with sounds of shuffling feet, cups of tea being stirred, murmured conversations and so on. Closing one's eyes it was hard not to believe that one was actually there amongst the diners.

Forgetting 'stereo imagery' and such considerations, the picture these speakers were creating was frighteningly real and vivid. And I use that term with no degree of hyperbole whatsoever.

On music as varied as Mahler and Carmel the FL1 's revealed many valuable strengths: for example they retained their dynamic and tonal balances regardless of the level they were being played at. Another striking feature was their handling of low level detail - subtle detail was presented lucidly and with great stability. Regardless of whatever else was happening in the music quieter information seemed able to pass through the FL1 without being adversely affected by other more dynamic signals.

Another aspect of the speakers performance that I found most impressive was the effortless way they handled high level transients: I was never aware of any sense of strain when the FL1 was called upon to cope with say a loud cymbal crash or heavily struck piano chord -no matter what was put into them they handled it with consummate ease regardless of the level they were being played at. As an aside, I would mention for the benefit of real SPL freaks that there is talk of stocked pairs of FL1's (i.e. a pair of FL1 's mounted one atop the other in a special frame for each channel). All I can say is that you'd need a large room and a very understanding wife to accommodate such an arrangement !

Naturally, before we can comment any further on this exciting new speaker we're going to have to live with a production pair-so it will be sometime later in the year before we can give you a full review of their capabilities. Suffice it to say that we're waiting with bated breath!

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Best;

Mark

(an imperfect
forum environment is
better than none)

superb, thanks for the details.

There's more stuff there than I think I've ever seen about these mythical beast.

cheers, Martin

P.S. here is your picture shown in-line so you don't need to click the link:-

In a perfect world, I would have known where this info had come from, and credited the source, which I am now pleased to do.

Apologies for any offence which may have been caused by this oversight.

Best;

Mark

(an imperfect
forum environment is
better than none)