ULTRA AUDIO -- Archived Article

May 15, 2003

JBL K2 S9800 Loudspeakers


What’s the greatest speaker in the world? It’s a question that defies a rational answer, because the top speakers all have their own individual sonic flavor, and personal taste plays a part. But one that would be sitting at the top of my particular short list right now is this JBL, christened the K2 S9800.

The JBL K2 S9800 is a flagship model from one of the largest and best-known speaker brands in the world. JBL is one of America’s finest; its original Californian roots go right back to the 1930s, though it now operates under the Harman International banner, with equal success in both the professional and domestic audio arenas.

However, JBL’s strongest reputation as an audiophile brand is in Japan, which has enormous respect for hi-fi heritage and tradition. This particular loudspeaker is the latest in a succession of models that have been specifically developed with the Japanese market in mind, drawing on a combination of the company’s heritage and its latest technologies. Indeed, although JBL introduced the K2 into Europe in mid 2002, long after its Japanese debut, the company decided only very recently to launch this made-in-the-USA model in its home market.

That’s largely, I suspect, because its shape and configuration are deeply unfashionable in today’s context. In a sense it’s an updated, floorstanding variation on the theme set by the highly successful 4320 Studio Monitor and its domestic L300 derivation in the 1960s and 1970s. Hi-fi archaeologists will be able to track its roots still further back to a speaker called the Iconic, which used a similar driver configuration and was first made by a company called Lansing Manufacturing in 1937.

Inside and outside the box

Choice of drive units does much to determine this speaker’s size and shape, and since this model uses a 15-incher for bass and much of the midrange, it is wide, tall, and unavoidably intrusive. This is essentially a giant two-way, although an additional supertweeter comes in above 10kHz for the final less-than-an-octave-plus ultrasonics.

None of these drive units is anything like conventional. The port-loaded 15-incher operates all the way up to 800Hz (which is more than half the audible bandwidth). It uses a traditional paper-pulp cone, a foam surround, and an Alnico (aluminium/nickel/cobalt alloy) magnet. The materials used might sound somewhat nostalgic, but the actual motor design is very advanced, using a "short-coil/long-gap" approach, with a laminated copper/steel outer gap sleeve.

A special horn driver then takes over for the three-and-a-half octaves from 800Hz up to 10kHz. This has 90 x 50-degree flares, with a 3" 435Be beryllium-dome compression driver. Sitting on the top is a type 045Be compression-type supertweeter, with a 1" beryllium diaphragm loaded by a 30 x 60-degree horn. Originally developed for JBL Pro systems, beryllium is incredibly costly because it is very rare and an exceptionally difficult metal to work. It also has an extremely high stiffness-to-density ratio (much higher than aluminium or titanium), so it is ideal for tweeter diaphragms.

Reflex-loaded by two large ports in the rear, the large enclosure is irregularly shaped and built from a mixture of 25mm MDF and Sonoglass resin. It is finished to a very high standard in a classy if rather gloomy high-gloss dark charcoal gray with black highlights. A light-gray option is also available. Floor spikes are supplied, along with coasters to protect a wooden floor, but no locknuts. Although the fore-and-aft footprint is relatively modest, the hefty total weight of almost 200 pounds ensures decent mechanical stability

Mounted in its own sub-enclosure to avoid acoustic vibration, the crossover network is particularly intriguing. It uses high-power air-cored inductors, and uniquely (very cleverly) pre-biased twinned capacitors (by means of a 9V PP9 battery), which improve linearity and help avoid crossover distortion. Two presets allow very subtle adjustment to the bass damping and relative treble level. Two pairs of terminals provide biwire or biamp options, while a switch bypasses the bass-to-horn network to permit full active drive.

My in-room measurements were very promising indeed. Placed well clear of walls, the K2 delivered unusually smooth and flat far-field traces, with a close-to-ideal, gently down-tilted overall characteristic. There is a little too much output around 500Hz, and some unevenness above 7kHz, but the result is very impressive overall, helped because the main horn, running 800Hz to 10kHz here, avoids the usual 2kHz-to-4kHz presence-zone discontinuity.

Sensitivity registered a very generous 93dB. The speaker is also a very easy amplifier load, with an impedance that never falls below 6 ohms. This K2 S9800 is well suited to lower-power valve amps, as well as regular solid-state models that can take full advantage of its 400W power-handling capacity.

In the listening room

So much for the basic description; what about the sound? First impressions were exceptionally positive, and I don’t think I have ever encountered a speaker that has quite so many good things going for it. Neutrality is exceptionally good, which is an excellent starting point, but this speaker does nearly everything else exceptionally well, too.

Dynamic range is magnificent. The speaker goes as loud as your mood (and your amplifier) takes you, yet above all shows wonderful delicacy of detailing even with the quietest of sounds. Realistically resolving the fine texture of massed orchestral strings is really difficult, but is something that the K2 simply takes in stride. It also possesses seemingly inexhaustible headroom, with a complete freedom from strain at all normal levels -- though it can get a little aggressive with some material when driven hard.

The bass manages to sound full, rich, and warm, without becoming in any way overbearing, and also seems beautifully agile and free from overhang. It doesn’t perhaps have quite the punch and drive that’s available elsewhere, but does manage to sound exceptionally natural at all times, which is arguably more important. The simple fact that it doesn’t draw undue attention to itself must be seen as a plus.

The K2's best trick has got to be the way it handles microdynamics -- tiny low-level details that provide clues to the size of a choir or an auditorium, and make audience applause sound creepily realistic -- even when operating at very low levels. Orchestral music in particular has a subtlety and realism that’s totally beguiling, while opera also combines great authority with fine voice articulation.

I found myself spending much more time than usual listening to BBC Radio 3, the UK’s excellent network classical music radio station. I’ve even started getting into Shostakovich for the first time, via a splendid (and cheap!) new recording of the 11th Symphony by the LSO under the baton of Msitislav Rostropovich on the LSO Live label [LSO 0030].

Popular music is equally well served by the JBLs, especially the acoustic live recordings, which include some of my favorites. Christy Moore’s At the Point: Live [GRACD 203] is a longstanding favorite from 1994, and the K2s were most effective at bringing out the humor of the performance, and the polished stagecraft of this very experienced performer.

More recently I’ve been exploring the double Live CD from Alison Krauss + Union Station [Rounder RRCD 610515], another exceptionally high-quality recording from this fine "modern country" band. The K2s highlight the superb musicianship and bring out the delicate dynamic layering of the often complex arrangements very well.

Through the window

Horn speakers are not to everyone’s taste, and while a number of visitors agreed that this speaker seems remarkably free from the vices normally attributed to the breed, some listeners might find it a little too ruthlessly revealing, preferring something rather more laid-back and restrained. While the K2 does have some aggressive tendencies when worked hard, taking no prisoners among poor-quality software, sources, or amps, its ability to "suck in" the listener and create involvement in even unfamiliar material is unparalleled in my experience.

One aspect of performance that’s somewhat different from the norm lies in the way this speaker interacts -- or rather doesn’t interact -- with the listening room. Most speakers have relatively wide dispersion in every direction, so that although the sound you hear is dominated by the direct sound from speaker to listener, it is richly augmented by room-reflected sound. However, both the K2’s large bass/mid driver and its mid/treble horns seem to have comparatively narrow dispersion through the midrange and treble, so there’s less room sound than is usually the case.

In that respect the K2 shows certain similarities to dipole panel loudspeakers such as the Quad ESL-988, which have a figure-eight-shaped distribution. This means that you hear more of the direct sound coming straight to you from the loudspeakers, and proportionally less sound reflected from the walls, floor, and ceiling than you would using a speaker with a much wider dispersion characteristic, such as the B&W Nautilus models.

Whereas the Nautilus 800 will tend to fill the room more, creating a strong impression that the musicians are actually sitting right there, the K2 and Quad provide more of an "open window" onto the recording sessions, revealing more of what the recording engineer intended, but less of the illusion that musicians are actually playing in front of you. This is neither praise nor criticism, as there’s neither right nor wrong here, but it is a relevant observation that has a significant impact upon the character of the listening experience.

This quality undoubtedly contributes to the very precise imaging, alongside this bulky speaker’s surprisingly good transparency. It’s not quite a match for the best dipole panels here, but is rather better than most box loudspeakers in this regard.

In the end

Some months down the road from its arrival, my respect for this remarkable speaker system continues to grow. It suits my brick-built 14’ x 8.5’ x 18’ suspended-floor/ceiling listening room exceptionally well, and has been getting me into all sorts of interesting new music. It’s essentially neutral, transparent, and dynamically realistic, all of which proves very revealing of the components to which it’s connected. For most of the time I’ve been using my regular Naim electronics, but the K2 clearly and unequivocally reveals the effects of changing components further up the chain, whether the actual electronics or accessories such as cabling.

There’s no such thing as the perfect speaker, because there are always design choices and performance compromises to be made. The K2 S9800 might seem like a faintly bizarre and unfashionable throwback in a modern-marketplace context, but there’s some comfort in knowing the illustrious history that is on its side. This is very much the ultimate two-way, with all the advantages of simplicity which that implies, brought bang-up-to-date with a supertweeter and the latest driver technologies.

…Paul Messenger

JBL K2 S9800 Loudspeakers
Price: $25,000 USD per pair.
Warranty: Five years parts and labor.

8500 Balboa Blvd.
Northridge, CA 91329
Phone: (800) 336-4525

Website: www.jbl.com    


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