Overview

The JBL K2 S9800 was JBL’s 2002 flagship, pairing a 15-inch Aquaplas-treated woofer with 435Be and 045Be beryllium compression drivers on proprietary SonoGlass horns in a three-way, passive floorstander. Each cabinet measures 1295 × 508 × 375 mm and weighs 90 kg. The design targeted very high output with controlled directivity consistent with JBL’s professional lineage. [1]

Scientific Validity

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Manufacturer specifications state 45 Hz–50 kHz (–6 dB) frequency response, 94 dB sensitivity (2.83 V/1 m), 8 Ω nominal impedance, and 400 W recommended maximum amplifier power. Third-party modern Klippel/CTA-2034 measurements are not available for this legacy model, limiting verification against current transparency standards, so the default baseline is applied. [1]

Technology Level

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Beryllium compression drivers and molded horns were advanced in 2002, but the platform predates today’s widespread use of simulation-driven crossover optimization and DSP linearization. Relative to modern designs that leverage computer-aided development and room-aware tuning, the technology level is modest.

Cost-Performance

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Comparator: JBL Studio 698 (current, passive 3-way tower). It offers equivalent user-facing functionality (passive, full-range stereo tower) and not-inferior measured performance for fidelity axes: smooth on-axis/early-reflections responses and neutral directivity from independent Klippel NFS testing, with rated extension to 36 Hz; sensitivity differs but is not a fidelity metric. [2][3][4]

Calculation: 2,199.90 USD ÷ 8,900 USD = 0.247 → 0.2 (one-decimal scoring).

• Review target price (denominator): representative used-market price snapshot. [2]
• Comparator price: widely available retail (each 1,099.95 USD; pair 2,199.90 USD). [4]

Reliability & Support

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JBL’s service network is global, but this discontinued model depends on legacy parts (including beryllium diaphragms) and specialist service paths. The heavy cabinetry and passive topology bode well for longevity, yet parts risk remains.

Rationality of Design Philosophy

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The K2 S9800 pursues high output and low distortion via compression drivers and controlled-coverage horns—rational goals for fidelity and listener-area control. However, absent modern data-driven crossover/DSP refinements, the approach is now outclassed by newer, more transparent implementations at far lower prices.

Advice

Buy for historical significance and the specific horn/compression-driver presentation if you value the object and are comfortable with maintenance and placement demands. If your goal is measured transparency per dollar, current towers like the Studio 698 deliver comparable or better objective performance at a fraction of the K2 S9800’s going price, resulting in a low CP score. [2][3][4]

References

[1] JBL, “Project K2 S9800 Owner’s/Technical Manual (specs: 45 Hz–50 kHz –6 dB; 94 dB; 8 Ω),” https://support.jbl.com/on/demandware.static/-/Sites-masterCatalog_Harman/default/dwd71d7033/pdfs/K2_S9800_OM_EN.pdf, accessed 2025-08-23.

[2] HiFiShark, “JBL K2 S9800 – model page / current listings (e.g., 8,900 USD),” https://www.hifishark.com/model/jbl-k-2-s-9800, accessed 2025-08-23.

[3] Erin’s Audio Corner, “JBL Studio 698 Tower Speaker Review (Klippel NFS, CTA-2034),” https://erinsaudiocorner.com/loudspeakers/jbl_studio_698/, accessed 2025-08-23.

[4] Best Buy, “JBL Studio 698 (each) – 1,099.95 USD,” https://www.bestbuy.com/site/jbl-studio-698-dual-8-woofer-6-mid-3-way-compression-driver-floorstanding-loud-speaker-each-dark-wood/6547547.p, accessed 2025-08-23.

(2025.8.24)