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楼主及楼上各位好:大官人给各位请安了!
请安也得带点礼物吧?下面一篇评论文章朋友看了以为是比较全面的一篇,请楼主及各位笑
纳.本人英文近似"文盲",除认识几个J(勾),Q(疙瘩),K,A(尖)以外一无所识,望各位同好海
涵!(当然也有帮顶的意思,说不定哥们那天也来一对,入伙了!)
Sonus Faber Extrema
The Review
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Martin Colloms listens to a moving-coil two-way taken to the dynamic extreme
Two-way, ABR-loaded, stand-mounted loudspeaker. Drive-units: 1.2" (28 mm) soft-
dome tweeter. 7.5" (190 mm) mineral-loaded polypropylene-cone woofer, KEF B139
or TDL 3021GTO3 bass unit used as an ABR (Auxillary Bass Radiator). Crossover
frequency: 2 kHz. Crossover slope: first-order, 6 dB/octave. Frequency
response: 35Hz-18kHz ±3 dB. Sensitivity: 88dB/W/m (2.83V). Nominal impedance:
4 ohms. Amplifier requirements: 200W maximum. Dimensions: 18.1" (460mm) H by
10.7" (270mm) W by 21.7" (550mm) D. Enclosure volume: 20 liters. Weight: 88
lbs (40kg) each. Finish: black-satin lacquer and solid walnut. Price:
$12,500/pair (matching stands cost $1500/pair). Approximate number of dealers:
7. Manufacturer: Sonus Faber, L. da Vinci, Arcugnano (VI), Italy. Tel: (39)
444-962699. Fax: (39) 444-962687. US distributor: Sumiko, 3101 Telegraph
Avenue, Berkeley, CA 94705. Tel: (510) 843-4500. Fax: (510) 843-7120.
Sonus Faber was founded in 1981 by Franco Serblin. Real wood has always
featured strongly in the construction of this company's evolving range of
costly, compact loudspeaker systems (footnote 1). The first was called the
Parva, now in its FM4 form. This was followed by the Minima, a Tablette-sized
model. The upmarket Electa came through in the last few years, followed by the
Amator-Electa. This series increases in size and weight with each new
introduction—for example, the Minima weighed 6kg, the Electa 12kg, the latest
Extrema a massive 40kg or 88 lbs.
The Extrema represents one of the fullest expressions of the art of speaker
design: performance rules absolutely, price only being a minor consideration.
(If you're building the speaker equivalent of an Italian supercar, why should
cost be important?) The Extrema's remarkable styling includes a deep front-to-
back ratio, all slopes and curves, with heavy sculpting in solid wood. It
certainly has an Italian "designer" quality. Standing on a massive six-pillar
iron platform of prodigious weight, the whole assembly beds down like the Rock
of Gibraltar.
Technology
This analysis leads with a feature which, as far as I can tell, is unique
(Sonus Faber has applied for a patent). Most designers would not have given it
a second thought, since classical engineering doctrine concerns the primacy of
efficiency. Sonus Faber, however, has rethought the concept of the high-pass
crossover filter, ignoring the efficiency dictum and daring to waste a small
proportion of an amplifier's output power to achieve a new crossover
realization without using any capacitors. If the speaker were to be used in a
battery-powered arrangement, the idea would be impractical, but for a mains-
powered amplifier, the consumption of a few more watts is likely immaterial—
probably less than the idle power of the higher-current-enriched class-A or
full class-A models generally available.
This crossover begins with the design approach adopted for the system, namely
the use of first-order rolloff slopes of 6dB/octave; a single reactive
component is used to divide each driver's working frequency range. This
appears to be an attractively simple concept requiring just two components: an
inductor in series with the low-frequency driver to roll out the high
frequencies, and a capacitor in series with the tweeter to roll out the mid
and bass. Advantages include a complete absence of electrical overshoot or
ringing, a smooth load impedance, and, with suitable drivers and an
appropriate physical alignment, a close approach to minimum-phase performance.
Minimum phase means that the phase varies linearly and smoothly with frequency
in a manner mathematically related to it by the Hilbert Transform. [The phase
response offers "just the right amount" of deviation for the frequency
response.—Ed.] Perhaps more important, a "minimum-phase" component will
reproduce a complete acoustic waveshape correctly, with all phase
relationships preserved (at least to within the accepted limitations of the
loudspeaker's defined overall bandwidth). The concept of "linear" phase,
however, is misleading; it implies that the speaker cannot have a defined
bandpass characteristic. Reasonable bandwidth limits are entirely sensible,
however, and are found in nature; furthermore, they are not in themselves a
cause of significant aural distortion.
The slow electrical rolloff rate of the simple first-order crossover
unavoidably results in a large overlap of response between the defined working
ranges of the drive-units. This mandates the use of very-wide-bandwidth
drivers of very uniform amplitude and phase responses. Rolling out the
bass/mid unit through the low treble is usually no problem with a modest
series inductor or "choke," and the electrical matching works well.
However, this simple crossover often gives a problem with the tweeter. The
usual series capacitor has the unfortunate property of reacting with the
tweeter's varying load impedance in its lower range due to the unit's motional
impedance. A severe and unwanted modification of the crossover rolloff occurs
with this interaction (fig.A, dashed curve). More complex, higher-order
crossovers are often used, together with complex correcting networks and/or
resistive loadings and dampings in order to get a better match between the
actual filter performance and the theoretical. Such complication goes against
the desire for simplicity and its associated rewards of low phase shift, good
dynamics, and, for Sonus Faber, an expressed requirement for signal
transparency.
Fig.A High-pass filter slopes: theoretical 6dB/octave (dotted/dashed); "Sine-
Cap" resistor/inductor filter (solid); and conventional capacitor filter
(dashed).
If, however, the tweeter has an extra-wide bandwidth, exceptional power
handling, and higher-than-necessary sensitivity, another route is available to
the designer. A first-order crossover can be achieved, not with a series
capacitor but with a single inductor, this connected in parallel with the
tweeter. The parallel inductor connection terminates the high-frequency driver
well, helping to control its natural fundamental resonance. For the inductor
to give a defined filter characteristic, however, there must be a series
impedance; in the case of the Extrema, a resistor (fig.B). This
resistor/inductor combination appears wired across the speaker input
terminals; it will dissipate power over the speaker's entire frequency range,
mainly according to the resistor value.
Fig.B Conventional first-order high-pass crossover filter (top) vs "Sine-Cap"
filter (bottom).
In the case of the Extrema, the series resistor for the treble section is
typically 20 ohms. This provides the required source impedance for the
crossover inductor, and also correctly attenuates the treble unit by the
required 4dB or so. Yet with the Extrema's nominal 8 ohm drivers, the total
system impedance does not fall below a 4 ohm minimum—it is nominally a 5 ohm-
rated design. Fig.C shows the high-pass filter's impedance curves, both for a
normal crossover with a series capacitor (upper trace) and for Sonus
Faber's "Sine Cap," parallel inductor case (lower trace). The former's
variations are normal and show a typical 8 ohm system, one without that 20 ohm
power in parallel over most of the range.
Fig.C Sonus Faber Extrema, electrical impedance with "Sine-Cap" crossover
(solid) and conventional crossover (dotted). (5 ohms/vertical div.)
On the minus side, the resistor must be capable of dissipating considerable
power. Assuming a 200W power handling for the speaker and a worst-case 10dB
peak:mean program dynamic range ratio, a 200W, 8 ohm delivery translates to
40V peak, or 26.4V mean. In theory, up to 20V of program energy applied to the
power resistor results in a possible flat-out dissipation of 20W. Taking no
chances, Sonus Faber has chosen a high-quality, metal-clad power resistor of
the type which may be bolted to a heatsink for optimum heat release. (The
latter is the small finned metal structure visible on the back of the
speaker.)
A key element in the Extrema design is the use of one of the world's best
tweeters, Dynaudio's 28mm soft-dome Esotar T330. Costly though it may be, this
unit offers not only an unrivaled combination of bandwidth and power handling,
but also low-frequency characteristics considered ideal for this type of
speaker design. With the system crossover set at a relatively low 2kHz (most
systems in this class have a crossover in the 3-4kHz range, up to an octave
higher), this high-frequency unit's low fundamental resonance of 500Hz and
high damping (Q=0.2) are considerable advantages. This assembly has a shaped,
vented center pole and a large, damped acoustic chamber behind the dome.
Fitted with a massive ring magnet, the metal faceplate allows firm fixing,
while the high-density coil uses a dense "Hexacoil" wind.
"Something special" is a good description for the unusual bass/mid driver,
including an exceptionally large "Hexacoil" motor coil for a nominal 220mm
framed driver of 145mm active diameter. This 75mm-diameter coil has a medium-
term thermal rating of around 200W, but will sustain 2kW in doses of 10ms
duration. Most 190mm bass/mid drivers have a much smaller 25 or 33mm coil, and
only a 50W rating.
Virtually hand-built to Sonus Faber's specification by Skaanings Audio
Technology in Denmark, the modular construction comprises the cone and motor
assembly, a large frontplate, and a system of bolts to secure the magnet and
pole system. For the Extrema, the almost rigid cone is made of magnesium oxide-
loaded polypropylene reinforced at the center by a concave polypropylene cap.
The long-throw cone's textured coating of a heavy carbon-loaded vinyl acrylate
provides further resonance-mode control. The front suspension is a tough,
partially foamed Neoprene of good mechanical "Q" to help preserve low-
frequency dynamics. The magnet is an "SD" type, with a high-conductivity pole
cap to short-circuit eddy currents and thus reduce inductance and inductance-
modulation effects, including third-harmonic distortion. Such techniques are
only viable where the system designer is allowed significant budget for drive-
unit R&D.
Moving down into the low-frequency range, the Extrema is a 20-liter bass-
reflex design with a difference. Belonging to the ABR, or "auxiliary bass
radiator" class, the moving plug of air in a conventional reflex port or duct
has been replaced by a moving solid diaphragm, in this case the extra-solid
polystyrene-wedge cone of the trusty KEF B139 bass unit (footnote 2). This has
been seen before in ABR service, for example in many of KEF's own systems and
the Ensemble series from Switzerland. If the ABR has good excursion
capability, which the B139 does, as well as a useful radiating area
(equivalent to a 10"/240mm driver), then good levels of low-distortion bass
are achievable without the "chuffing" or "wind" noises heard from a small
port. In addition, the acoustic opacity of the wedge diaphragm ideally will
block the egress of the enclosure's potentially harmful acoustic standing-wave
modes.
The Extrema adds a neat twist to the tale: here the B139 is not just a
diaphragm but the complete bass driver complete with motor coil and magnet.
While careful schemes could be devised for bass damping using acoustically
resistive apertures, Sonus Faber has exploited electromagnetic damping. They
place a desired resistor across the auxiliary woofer's motor coil; damping
energy appears in the moving-coil and is dissipated in the resistor.
Sonus Faber has gone even farther in their exploitation of this principle,
providing user-variable bass damping in the ABR range, effective over an
octave centered on 50Hz. No less than five switch-selected positions are
available. This is only too easy to accomplish once the working principle has
been adopted. The step resolution is fair enough at 1.5dB once the ABR output
is integrated into the main response. A mass-loading cylinder has been applied
to the B139's diaphragm to lower the resonant frequency.
The substantially built Extrema rivals the Wilson WATT in the quality of its
construction, weighing 40kg (nearly 90 lbs each). The black satin central
section of the enclosure is built of a patented sandwich construction—seven
vertical slabs in all—bolted together to form a highly rigid, nonresonant
structure. The outermost slabs are made of solid walnut 1.25" thick,
beautifully finished and lock-mitered in a series of vertical steps to produce
a warp-free assembly.
The front of the enclosure is heavily sculpted and beveled, both for reasons
of style and, more important, to reduce diffraction effects. Asymmetrical
enclosure boundaries help, as do curved surfaces, while low diffraction
considerably helps stereo focus. The sides are parallel, but front and back
panels are strongly sloped; this, together with the tilted top surface,
strongly dilutes standing-wave effects inside the enclosure. The tilted front
corrects time alignment between the two drivers.
Sonus Faber provides a utilitarian, 55cm-high, all-steel speaker stand with a
matte crackle finish in black enamel, and thick top and bottom plates. The top
plate, rather small given the Extrema's footprint, suggests no coupling
technologies bar the obvious use of mastic pads at the corners. The larger
bottom plate is threaded to take floor spikes, in this instance terminated
with small, radiused balls. I used my own sharp spikes to ensure a good key to
the floor through my carpet. The stand has six large rectangular pillars,
vertically oriented, and comes ready-filled with lead shot and sand. The
stands, extremely heavy and super-rigid, are devoid of audible resonance.
I also tried the Extremas on a pair of Acoustic Energy AE-2 stands, which did
not look as good. Furthermore, the height was too great for the time-aligned
mid/treble axis to be presented to a seated listener's ear level. With a
speaker of this caliber, optimal stands are crucial; the Extrema stands worked
well.
Extremas are burned in for 60 hours at the factory before shipping; mine
sounded fine straight out of the box.
Sound
Hearing is believing. From the beginning, the Sonus Faber sounded very good,
proving relatively uncritical of the matching equipment, its location, or
listener position. That's not to say such matters were unimportant, but simply
that the speaker's design is fundamentally correct: its balanced authority
dominated the proceedings from the start.
A number of fine, recommendable speakers can only scale the audiophile heights
when their idiosyncrasies have been pandered to. They are sufficiently flawed
as to need great care taken with placement, height, separation from
boundaries, and angling, as well as being very sensitive to the complementary
sounds of cables, power and control amplifiers, even to CD sources and moving-
coil cartridges. They might have suspect bass and require the most careful
positioning of both speaker and listener to involve the room acoustic in some
kind of bass equalization. The result may still be more than satisfactory, but
it is always something of a compromise. Speakers unduly critical of height or
lateral axis tend to have poor drive-unit integration as well as uneven
directivity patterns. The fact that a unique axis can be found on which
frequency response sounds flat doesn't affect the sound off-axis, which then
voices the room acoustic in a characteristically uneven pattern. A disparity
is then apparent between the optimum on-axis sound and that present in the
room.
I felt comfortable with the Extrema's sound early on in the system alignment.
On- and off-axis, in the room and around the speaker, the tonal quality
sounded consistent and neutral. In my book, this behavior implied fundamental
strengths in overall integration, tonal accuracy, and a good directivity
pattern—a most welcome first result.
In fact, the Extrema's tonal accuracy proved to be its enduring strength,
distinguishing it from a large number of audiophile speakers. The Extrema
often sounded like a well-set-up Quad ESL-63 electrostatic mixed with BBC-
derived balances, such as that of the Spendor S100 and S20. In some recent
speaker reviews I have commented that some designs have sounded a touch
exaggerated, almost "speakerish"—recognizably good, but insufficiently
neutral to allow one to forget the sound sources. The WATT 3/Puppy, however,
can do the trick. Now, so does the Sonus Faber Extrema. Although not entirely
devoid of "character," the Extrema proved consistently faithful to balances
present on the recordings. In this respect, it could be regarded as a small-
scale recording monitor.
For consistent tonal neutrality, a speaker also needs to be low in coloration.
Coloration—false tonal or timbral effects occurring in narrow sectors of the
frequency range—may be due to a peaky area of the frequency response or long-
term resonances or hangover (such as bell-like acoustic features hidden in the
overall sound) occasionally brought into prominence by the spectra of specific
instruments. The Quad ESL-63 is one of the finest low-coloration loudspeakers;
for moving-coil designs, the WATT 3/Puppy and now the Extrema run very close
seconds. Praise indeed!
The subjective frequency response was wide and linear, with the low-frequency
output solid right into the bass. The treble was open and effective to the
edge of audibility. Moreover, this speaker sounded uncannily smooth, never
aggressive, hard, or unfriendly except where the program demanded. It was very
easy to live with for long periods. This is an underrated factor; often those
excitable, exciting "flavor-of-the-month" designs prove exaggerated and
fatiguing in the long term. Sometimes they insist on playback volume levels
that are too high for long-term comfort. I see the Extrema settling into a
classically furnished room and being left to get on with the job for years to
come.
Having covered the case for accuracy and lasting quality, the audio
conservatives have been satisfied. But can the Extrema boogie? The answer is a
resounding "Yes—and how!" This speaker does not quite match the remarkable
rhythmic integrity of the WATT 3/Puppy, but it surely comes close—so close,
in fact, that without the WATT available as an immediate reference, I was
indisposed to doubt the Extrema's rhythmic capability. It can rock with the
best of them, aided by its facility to fine-tune the bass to a valuable
midline between the conflicting attributes of weight vs crispness at low
frequencies.
On both classical and rock material the Extremas repeatedly presented the
music's pulse, transforming the reviewing task from chore to pleasure. Quite
simply, the speaker was fun to be with. Another vital area was also dealt with
most effectively: its rendition of transients was fast, lively, and accurate.
Compressive effects were very low; the speaker sounded very dynamic, explosive
when so required by the source. Crescendi were seemingly effortless, even with
big musical forces; the Extrema's dynamic capability went far beyond
expectation for a stand-mounted, two-way design. In this respect it happily
matched the performance of the larger high-performance three-way designs.
I found the Extremas' soundstage to be very well focused, a quality maintained
from far left to far right. Stage width was very good, and in the right room
could be increased by careful balancing of the speakers' positions relative to
the side walls. Height was also presented well, though not to the inflated
degree achieved by such tall speakers as the big panel systems or the Infinity
IRSes. Height information was presented more stably than usual. However, the
Extremas also performed exceptionally well in regard to stereo depth, sounding
as transparent as the best of them; images were deep, clear, and very
spacious. The neutral tonality helped preserve a believable perspective, and
the high degree of depth layering was most entertaining and rewarding.
The very good transparency was allied to high-definition, high-resolution
performance. Definition was excellent, with much detail evident over the
Extrema's full working frequency range. It was obvious that the wide variety
of electronics used during the review process often set the practical limit to
the resolution, not the Extrema. Much like the WATT, the better the sources,
the better the Extrema sounded.
As speakers go, the Extrema was relatively unbounded, justifying a big
expenditure on ancillary equipment if its owner feels so disposed. In this
respect it reminded me of a scaled-up, turbo Epos ES11. On one occasion,
however, I used the Musical Fidelity Tempest/Typhoon budget pre/power
amplifier set (ca $1000), yet the Extrema remained well-balanced and
enjoyable, albeit working at an understandably lower level of quality.
The Sonus Faber's bass was remarkably good for a compact speaker; so good that
its attack and verve embarrassed many prestige designs. It played tunes
consistently well on electric guitar and bass viol, and had a real grunt at
the bottom end which remained consistent over a decent dynamic range. It's
rare to find a more-than-satisfactory bass extension like this allied to good
timing and good dynamics.
Whereas a naked WATT used in a domestic setting pleads for a woofer system
(broader band) to create a "free-field" tonal balance rather than the
nearfield-monitor sound Dave Wilson created (hence the WATT/Puppy's success),
the Extrema didn't sound as if it lacked anything in the bass. In fact,
experience so far with subwoofers and their necessary electronics teaches me
that the Extrema is better left well alone. As with the Wilson design, I find
it all too easy to impair the innate quality and transparency of such speakers
with bolt-on accessories. The Extrema's bass was powerful, satisfying, and
well-extended; I was happy to take it exactly as it came. If you want fine
subwoofer performance down to 20Hz or so, look elsewhere.
Though the Extrema did not and could not deliver output in the really low
bass, what it did give was meaty and satisfying. But it's certainly no
subwoofer: the bass range stopped pretty quickly below 27Hz in a normal room.
Excessive underdamping will increase the apparent extension, but at the
expense of some subjective slowness and an impairment of that remarkable foot-
tapping sense of timing.
The facility for the user to adjust the bass power in the 35Hz-70Hz octave,
centered on 45Hz, was most useful not just for correct alignment in the
optimum room position (to give the best stereo image, low coloration, bass
uniformity, and extension), but also for some measure of program tuning. The
adjustment was fine enough for surprisingly critical adjustment.
For example, I preferred the damping set higher for loud, fast rock material;
for older, drier classical recordings played at more modest levels, a
judicious reduction in ABR damping helped fill out thinner recorded balances.
Optimally set, the Extrema could be driven hard in the bass, that rear-woofer
diaphragm really earning its living, yet doing so without "chuffing" or
distortion. However, the midrange began to go cloudy at the bass-power limit.
Moving up in frequency, as implied earlier, the Extrema's midrange was not
perfect, but then it never is. There was a trace of recognizable polypropylene-
cone "cuppy" sound right in the midrange, plus a mild thickening
and "woodiness" in the lower tenor range. But the upper mid was quite free of
hardness or glare, more than balancing the effect. The mid entirely avoided
that excessively thin tendency heard in a few recent Stereophile-approved
speakers. One or two have to be belted hard in order for the lower mid to make
its presence felt; in some cases, great care is needed with matching or
sources to achieve a good result.
Treble can be a contentious range; characterizations such as coloration and
uniformity are more difficult to attach to a given speaker because the sound
of the treble is so strongly founded on the adjacent mid-frequency range. The
treble may be fine in itself, but if the join to the mid is incorrect (for
example, a step down in level of as little as 2dB), then the system might be
described as dull or enclosed, lacking sparkle or air. Conversely, a similarly
small step up could result in characterizations of "toothy," "sibilant,"
stringy, and thin sounds. Many speakers suffer far more severe exaggerations
than this!
It's a tribute to the Extrema that its treble was never too obvious, never
drew significant attention to itself, never got in the way of the speaker's
overall clean, neutral performance. It was sufficiently extended so as to
provide good air and sparkle in the reproduced acoustic, perhaps just a shade
sweet in the extreme treble. A Magneplanar "R"-series owner could well be
cognizant of this aspect of sound quality, this ribbon range capable of a
strong output to beyond audibility.
The treble was smooth and well-integrated, essentially true to the harmonic
shading of the harmonic range of mid sounds: bell and triangle sounds were
excellent, vocals quite crisp and articulate, string tone natural and
unstrained. Above all, the highs were free of perceptible brittleness or
hardness, and had a vital and generous measure of transparency to boot.
Rarely does a review speaker sound so familiar, insinuate itself so easily
into the evaluation process. There was little for me to come to grips with in
the Extrema's sound other than finding a fair measure of its quality.
I could describe how it sounded on specific LPs and CDs, but I feel that to do
so would belabor the point. From here on, it's up to you.
Conclusion
Salient points include the Sonus Faber Extrema's high cost even without the
mandatory stands taken into account, a commensurately fine,
classic, "furniture"-grade build and finish, and a performance which reaches
far beyond the accepted boundaries for a compact two-way system.
The Extrema's design attributes include a smooth, extended frequency response
attained with very good directivity. The sensitivity is usefully above
average, and while the amplifier load factor is lower than 8 ohms, it could be
regarded as a "kind" 5 ohm load. The power handling is high, allowing for a
decent maximum sound level and a good dynamic range, a performance maintained
into the bass—remarkable for the class. Still more extraordinary is the good
bass response to 27Hz in-room, plus the fine-tune bass control. Distortion is
low for a moving-coil design, and phase shifts are also low, tending to
improve focus stability. High resolution is obtained at both high and low
signal levels.
Subjectively, the Extrema is essentially well-balanced, with very natural
dynamics and rhythmic capability. Soundstaging focus, width, and depth are in
the first rank. Coloration is quite low, mainly a richness and "woodiness" to
the midrange, and a related dulling of presence. The Extrema is a little
sweeter and more laid-back than it really needs to be. Such are the quality,
power, and extension in the bass that consideration of a subwoofer is
academic. The speaker's ability to deal equally well with both rock and
classical material was particularly impressive.
Aspects I'd like to see improved include the useless grille. Luckily it is
easily detached, and the drivers themselves are physically tough. I would also
like to see a stronger, larger top plate on the stand, and a more considered
speaker/stand interface, perhaps with a vibration-free locking assembly for
safety. I'm also doubtful about those ball-headed floor spikes.
This review comes with a health warning from the critic: I liked these
speakers. Their stylish design would suit many a well-designed, well-furnished
modern lounge. They stand as art objects in their own right, far removed from
the rectangular box syndrome. If asked to rank them in
Stereophile's "Recommended Components," I would place them in the top end of
Class B, failing to meet Class A by definition of that pedantic last 7Hz of
bass required to meet Class A's "full-range" standard.
I admire the commitment, dedication, and craftsmanship which have gone into
this effortlessly musical transducer. As a high expression of the art of
audio, the Sonus Faber Extrema certainly meets the performance challenge set
by its high price.
Sidebar 1: Specifications
Description:
Two-way, ABR-loaded, stand-mounted loudspeaker. Drive-units: 1.2" (28mm) soft-
dome tweeter, 7.5" (190mm) mineral-loaded polypropylene-cone woofer, KEF B139
or TDL 3021GT03 bass unit used as an ABR (Auxiliary Bass Radiator). Crossover
frequency: 2kHz. Crossover slopes: first-order, 6dB/octave. Frequency
response: 35Hz-18kHz ±3dB. Sensitivity: 88dB/W/m (2.83V). Nominal impedance:
4 ohms. Amplifier requirements: 200W maximum.
Dimensions:
18.1" (460mm) H by 10.7" (270mm) W by 21.7" (550mm) D. Enclosure volume: 20
liters. Weight: 88 lbs (40kg) each.
Finish:
Black-satin lacquer and solid walnut.
Price:
$12,500/pair (matching stands cost $1500/pair). Approximate number of dealers:
7.
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