Stereo
MAGAZINE FOR HIFI. HIGH END. MUSIC
Special offprint from Stereo 10/99

Hi-fi exclusive loudspeakers
Bridging the Gap
 

Presenting one of the undisputed stars at this year’s “High End”: Fischer & Fischer Super Speakers SL 1000. This monumental sculpture boasts genuine novelty and a remarkable tuning and balancing philosophy.

By Holger Barske

He could have done it the simple way: Blessed with long years of experience and a solid base in the market in the “middle-range” high end segment, Thomas Fischer could have had it easy by simply “blowing up” his existing loudspeaker design which pursues a continuous structural line, thus creating a flag ship in the least complicated manner.

Fischer resisted the allure of simplicity and pursued a very different course not partly thanks to his long time comrade-in-arms, Michael Mudra, who is responsible for a wealth of extraordinary structural details on this exceptional modulator.

Above all, the casing material has remained the same - Sauerland slate. On account of its dampening features without peer, it eludes any form of criticism. As the Fischer & Fischer SN 400 (see STERO 8/99) has recently proved, there are things other than a main distribution frame and backing plates that have moved the subject of casing for loudspeakers into a whole new light.

The new design makes it completely different from the other “1000” Series. It expresses itself in truly impressive numbers: Four separate modules per speaker and seven drive unit loudspeaker chassis (plus two passive membranes and a bass reflex tube) form as a whole an astonishingly delicate-looking sculpture weighing more than 250 kilograms.

 Let us begin with a small sensation: The SL 1000 emits low bass sounds according to a never-before-seen principle that Mudra calls “BCD”, short for Bass Compression Drive. It functions as follows: Two bass membranes mounted directly across from one another at a short distance are activated in the same direction and exert compression on the air volume located between the membranes. This air volume moves to the side under this high pressure. The closest analogy is that of loudspeaker engineer, Oskar Heil, whose jet tweeters work according to the same principle: Take a cherry pit and press it between your thumb and forefinger. The pit will catapult like a bullet to one side. With respect to the Fischer speaker, the practical application of this principle is as follows: The lower and rear slender modules have exactly the same net volume. They each house a Scan Speak woofer with a 21 cm diameter and a passive membrane of the same size. They are set up an exactly defined distance — in this case — 4 centimetres and form the deep bass unit of the speakers.

In a trade against conventional approaches, you gain a series of benefits with this system: similar to the Horn principle, the membranes are excellently dampened so that the sound pressure can occUr without a high dispersion of the wobbler. In this way, an impeccably linear impedance progression can be achieved as a by-product and more importantly, excellent pulse response. According to the design engineer, the arrangement vibrates in and out ten times as quickly as a single module without its counterpart! This, to be true, is confirmed most impressively by both measuring technology and by the sound results of this exceptional loudspeaker.

 The Sauerlanders elected to use remarkable procedures for the frequency range above the deep bass. Among other things, three magnesium chassis from the Scandinavian manufacturer, Seas, are employed. Their light weight and stiff metal membranes are considered exceptionally precise and with a high resolution but difficult to handle. Above their transmission range, they are very “messy” with respect to material resonance that can only be prevented by selecting the ranges of the frequency separating filters with the utmost care.

 One of the candidates, a model with a 21 cm diameter, is enthroned with a casing on the top of the SL 1000 and looks after the fundamental audio range.

 Last, but not least is the middle casing called the main module by the manufacturer. It houses a complete three-way system of which only the mid-high sound compartment can be seen from the front. The 18 MHz bass is seated on the rear side and emits in unity with the bass reflex tube. At the front, two 13 MHz magnesium mid-range membranes work on the ventilated casing: Slots at the top and the bottom of the rear walls supply the tuning balance.

 Finally, there is the tweeter that continues to enjoy worldwide fame; Dynaudio’s legendary Esotar. Although it has been around for some time, the fabric dome element is considered a prime example of fine resolution and sparkle. Its price, however, is as extravagant as its quality: A pair of Dynaudio’s costs a princely 1350 deutschmarks to change hands.

Have you been keeping count? In total, two sound emitting elements are meant to pave the way for the SL 1000 into audiophile heaven. In order to delegate the jobs cleanly to all the drive elements, exceptional filter equipment is naturally required. The separating filter is broken down into four single PCBs located in the scene of the action. The counter-effect of the individual brands is thus ruled out completely. The entire works is supplied with power via three pairs of terminals located at the rear so that even tn-wiring is possible. However this is not necessary because the manufacturer makes a multitude of high-grade pure silver cables available which carry the signals to their destination.

The gods have left sweat — litres of it — in awe of the sound revelation provided by these speakers. No chance of shifting these monstrosities to their optimum acoustic location. To change the location of the speakers, the speakers to their optimum acoustic location. To change their location, the speakers would have to be dismantled carefully down to their 16 plastic cylinders resting on the layers of the slate. In the auditory room of “STEREO” we had the pleasure of carrying out this action three times. After that our hard conditioning training requirement was met.

The initial sounds from the slate towers were breath taking.

 No dynamic loudspeaker as far as I know transmits such a sudden and inertialess input signal. Only the most noble speakers of competitors can reproduce a sound so apparently uninvolved and unbiased, If there were not that minor, but perceptively nasal discolouring in the mid-range, the SL 1000 would have secured into place in the selected circle of top references in just a few minutes. This discolouring, which irritated us in the beginning, can only be perceived under remarkably neutral conditions such as those offered by the STEREO audio room. Fortunately, the source could be located relatively quickly. The bass casing reflected the rear sound components of the mid-range element. This is why this discolouring can be perceived even more clearly from the side of the loudspeaker. A remedy was, however, found very quickly. Respectively positioned strips of absorbing material solved the problem in a lasting way. This modification will be introduced into the series immediately. If you thought that nothing more could stand in the way of hours of unspoilt music enjoyment, then you are right to a certain extent: the drive unit output stage must be selected prudently as the SL 1000 distorts it, bringing out the very different character of the output stage to light and magnifying it! The output stage must be heavy-duty and powerful as the loudspeaker impedance is 2 Ohm over a long range. This is why our dearly beloved Pass Monos X600, whose incomparable agility the Fischer modulator documents in an exemplary way to be sure, fails, as a little reinforcement is missing in the very low frequency range: If the rather low dampening factor of the pass blocks is taken into consideration — no wonder. The four-star Bolinde Plinius SA 100 Mk3 was considerably more exciting. Nevertheless, the merciless slate speakers showed their limits, which is understandable when the price of this class of amps is taken into account. The last spot of suppleness requires a reach into the reference region: we were only quite happy in the end with the Accuphase (battery phase) A-50V and as an ultimate solution — the Mark Levinson Mono No. 33H, decent in every respect.

The depth and precision to which these dream loudspeakers illuminate the action is not achieved by any other modulator I know. This is even more amazing as four individual sound sources must be reconciled. This job must truly be done with much daring. Just for this reason alone, I take off my hat off to the design engineers.

An acoustic projection accompanies this modulator to such a breadth that it can only be called “gigantic”. Despite an almost parallel alignment, a tie-down focussing element is created and five variations in the different layers of the low end are perceptible — not even in a spectacular way, but rather in natural dimensions. The musicians on stage are not transposed kilometres away in depth, but are rather only a few metres away at maximum. The SL 1000 maintains this realism as one of the few in its genre.

These loudspeakers only initially provide a little surprise with regard to their sound.

He, who is expecting bloodcurdling deep sound orgies, will learn his lesson quickly.

The bass tuning balance range is clearly within a narrow band, which is the intention

of the inventor. In this case, a special feature of the modulator cones to fruitation: it has been bred for a “normal” living environment no requiring such corrective measures that ruin the surrounding architecture, as for example our audio room would need. Around 30 square metres suffice completely to allow the SL 1000 to unfold its true potential. Even one or the other window surface may act a reflecting surface without diminishing the quality of the “1000”. You know, of course, what this means: - 500 kilograms of loudspeakers in addition to their pertaining drive sets had to be dismantled and distributed respectively to form three vehicle loads as well as transported to a home-like environment — to a “more realistic” surrounding. And what should I say, but that it was definitely worthwhile.

In the press rooms, it could be insinuated that this super modulator holds back to a certain extent in the general~.dynamic range, but none of this could be felt — to the contrary:

All my experiments with large-volume loudspeakers have failed bitterly because — although I was bathing in bass sound orgies — these was no contour to speak of. The Fischer & Fischer speakers set the lead down the correct path. I have scarcely ever heard such harmonic, such a perfect music reproduction as this. So crisp and clear down to the lowest layers; with membranes bonded literally to the signal progression, this speaker defines what is feasible under the circumstances. Of course, the other way round also applies: If you wish to drown a ballroom in sound waves, then you can quickly purchase a JM Lab Utopia: The overall experience is sure to be more resonant. The tuning balance of the SL 1000 has met an engineering challenge and has shown the courage to bridge the gap. It deserves acknowledgement, as you well know: Welcome to the circle of the elite!

The Sauerland exceptional speakers leave most of their competitors far behind. They outshine the others with their power use of material, fine craftsmanship and their few technical genuine delights. Thus we wish to welcome the shiny back beauty as the youngest member of the top reference team.

Stereoo Test

Sound Level

100%

 Price / Performance

 Excellent

 Laborreport

Laboratory Report

The amplitude progression appears to be rather eccentric, which is, however, not surprising when the engineering design is taken into account. In a living space, significantly more bass would be on hand and the drop in the presence range would disappear. The step response, on the other hand, is excellent for a system with seven drive units. Thanks to the BDC arrangement, even the bass components vibrate extremely quickly. The impedance record reveals three Ohm as a mean value.

Dimensions: 26 x 147 x 66 (width x height x depth) Warranty term: 10 years

 

Fischer & Fischer SN 400

The cabinet panels of the Fischer & Fischer SN 400 speakers are around 420 million years old. In light of the fathomless age of the material, the price of DM 14 400 for a pair of speakers is easy to comprehend.

 by Holger Barske

 Special offprint from Stereo 8/99

For almost a half a billion years, Mother Nature has compressed and shaped soil from a dim and distant past into solid rock — soil from an era not even showing any traces of the dinosaurs, who themselves, have been extinct for aeons. The rock in question is still around today: slate.

Sauerland, Germany is home to an especially precious and homogeneously formed slate. So is it not the most natural thing in the world for a loudspeaker manufacturer in this area to make use of local materials? The benefits of slate as speaker cabinet material are obvious: Slate is as heavy as lead and consists of many layers — like flaked pastry. These features enable it to attain its exceptional muting properties that cannot be achieved practically with any other conventional material used in loudspeaker construction. In a slate loudspeaker cabinet, only the loudspeaker baffle vibrates and not the enclosure. Although a number of manufacturers have claimed to have vibration-free casings, it first becomes clear how important this aspect can be, once your eyes, or better ears, have feasted on the products of Fischer & Fischer.

 The eye-opening feature about the cabinet material of this free-standing SN 400 is its weight. Each of these upright floor speakers weighs about 85 kilograms. The cabinet is based on a three-way design. By installing, the woofer in the side of the speaker, a relatively slim silhouette has given the speaker cabinet a polished finish. This construction, which has become very popular in the past few years, is a Fischer & Fischer original, by the way.

 And while we are at it: the woofer is a 21 centimetre model right off the shelf of the currently most reputable and leading Scandinavian chassis manufacturer: Scan Speak. It works on the principle of a reflex tunnel arranged at the front. This principle, which can genuinely said to be an exception to the rule, is also applied to the low to mid-range frequencies. This makes particularly sense as the 18 cm woofer responsible for this range, also from Scan Speak, hands over the job to its mates installed in the side of the speaker cabinet only when the frequencies get very low and thus can certainly use the bass-reflex-supported low-pitch playback. The transmitter used for this purpose also enjoys an excellent reputation. We are familiar with its characteristic carbon fibreboard membrane from a whole series of top quality speakers. In the Fischer speaker, it is on a small tapered ring allowing it to protrude slightly from the acoustic baffle. In connection with the tweeter mounted in a slight depression, this construction promises to deliver an immaculate time response in the pick-up range. The tweeter originates from Dynaudio’s high-class Esotec series.

However, at the Fischer factory in Sauerland, it receives a completely new front section in the shape of a “key” lined with a layer of felt, which was described in a previous article.

 The nature stone hewn cuboids delight the beholder with their design entailing much time, energy and tender loving care. The mighty diplexer princely resides on a thick acrylic plate on the rear panel. Three pairs of solid unalloyed copper terminals serving as links peep out throughout the cabinet. Although this method makes tnwiring possible, the massive solid copper bridges along with a set of loudspeaker cable promise to deliver unlimited enjoyment and plenty of it.

 In the first instance, the 400 model impresses the listener with its dust-dry, deep embracing bass. The sound may- appear to be a little “thin” in the lower range, but just seconds later the listener will discover the source of his misconception. In this case, merely the basic sound resonaces that classical wood speaker cabinets produce, making the listener believe he is hearing the low frequency volume when he is not, have disappeared. If there is not really any information on the very low frequency range in the material on the product, then these speakers do not produce any sound in this range. Thanks to the subtle presentation of living, breathing power, the designs offered by Fischer greatly differ from the products of

most competitors. So how can a smooth pick-up from an unmuddied bass to the basic and mid-frequency range be created? The lively 18 cm baffle has reliably demonstrated that it is the key to all: it bewitches with its pronounced colourful and expression-rich playback, always dynamic and at its best at any pitch. In the first instance, voice reproduction naturally profits from this performance which the extraordinarily dedicated SN 400 with a feeling for timbre and nuances succeeds in achieving. A silky, but simultaneously powerful high-frequency range produces a melodious blend. Virtues that not every fibrous tweeter features.

 The Fischer & Fischer SN 400 is also a loudspeaker rather unbiased about its set-up location. The SN 400 speakers can be a considerable distance apart when set at a very low angle to one another in the auditory area without jeopardising the focussing ability of the SN 400 or permitting the speakers to themselves become a source of resonances. The Fischer approach pays off in any case: The exceptionally stabile speaker case material, coupled with a carefully engineered three-way design has a most definite say in its price class. By the way, the 400 model can only be ordered as a SL 400 for an extra 2 600 deutschmarks for a pair of speakers. Their surface is undergoes a fine and impeccable finish until smooth and can be painted in any colour of the rainbow so that no more can be seen of the wonderful quarrystone. This is if you like this sort of thing. Myself, I prefer the nature stone version so that there is no mistake about this being a speaker made of wood - which scarcely cannot happen anyway, once you have taken a moment’s time to listen to the sound.

 Laboratory Report

 We are accustomed to the balanced amplitude frequency response characteristics of Fischer & Fischer equipment; the SN 400 is no exception; the bass goes down to about 30 Hertz (at —3 decibels) and only falls below this level very gently. The drop in the high frequency range at a level of 6 kilohertz is not within the range of hearing and it disappears when the sound is measured outside the axis. The transient characteristics of the three transmitters occur surprisingly quickly showing no irregularities in this case.

 Dimensions:23 x 111 x 35 cm (w x h x d)

Warranty:  5 years

The latest in upright floor speakers of the Sauerland manufacturer reveals a successful pairing of composure and temperament. Thanks to their ultimate casing material, the speakers boast completely uncoloured tonality and light-as-a-feather response. A true all-rounder only seldomly found in this price range!

Stereo Test

Sound Level

83%

Value in terms of price and performance

Excellent