Short answer: the KEF Reference 203 for better sound quality, the JBL HDI-3600 for the lower price. The KEF Reference 203 ranks #12 of 56 floorstanding speakers at $5000. The JBL HDI-3600 ranks #21 at $3800, $1200 cheaper.
The case for the KEF Reference 203: An unusually accomplished 4-way design for its era: excellent on-axis linearity (within about +/-3dB), genuinely good directivity both horizontally (~55 degrees) and vertically (~40-50 degrees). The tradeoff: This is a 20+ year old, long-discontinued speaker only findable secondhand (Facebook Marketplace, Craigslist, audio forums) - condition, driver matching, and component aging vary by unit.
What the JBL HDI-3600 gets right: CEA2034 spinorama shows a fairly even on-axis response and flat overall frequency response, with high 90dB sensitivity and very low distortion through the midrange. The catch: A wide shelving-down above 2kHz affects the in-room response, and vertical dispersion is a bigger issue than horizontal - the reviewer noted the dip is wider here than on the smaller HDI-1600, making it more audible.
Buy the KEF Reference 203 if sound quality matters more than the price. Buy the JBL HDI-3600 if the price matters more than sound quality.
Specifications Side By Side
| KEF Reference 203 | JBL HDI-3600 | |
|---|---|---|
| Price | $5000 Discontinued | $3800 |
| Ranked | #12 of 56 in Large Size Floorstanding Speakers | #21 of 56 in Large Size Floorstanding Speakers |
| Bass Extension (-10dB) | 37Hz (measured, Erin’s Audio Corner) | 62Hz - the on-axis curve also shows an unusual step/dip around 40-55Hz that may be a near-field-scan artifact for this tower (measured, Audio Science Review) |
| Bass Extension (-3dB) | 51Hz (measured, Erin’s Audio Corner) | 78Hz - the on-axis curve also shows an unusual step/dip around 40-55Hz that may be a near-field-scan artifact for this tower (measured, Audio Science Review) |
| Dimensions | 1067H mm (42" tall) | 40.5"H x 10.2"W x 13.5"D (1029 x 260 x 343 mm) |
| Impedance | 8 ohms nominal (3.6 ohms minimum, measured, Erin’s Audio Corner; 3.2 ohms per manufacturer spec) | 4 ohms nominal |
| Sensitivity | 88dB (2.83V/1m, measured by Erin’s Audio Corner) | 89.5dB (2.83V/1m, measured, Audio Science Review) |
| Drivers | 1x 0.75" supertweeter, coaxial 1" dome tweeter + 6.5" midrange, 2x 6.5" woofers | 2410H-2 1" compression driver, 3x 6.5" Advanced Aluminum Matrix woofers |
| Weight | 58 lbs / 26.3 kg (58 lb) | 61.7 lbs / 28 kg each |
| Woofer Cabinet | Bass reflex, with switchable flat/cut/lifted bass ports for wall placement | ported, dual rear-firing |
| Crossover Frequency | 400Hz, 2.7kHz, 15kHz | - |
| Discontinued | Yes | - |
| Frequency Response | 55Hz - 55kHz ±3dB (Manufacturer specified) | 38Hz - 30kHz (+/-3dB) (Manufacturer specified) |
| Recommended Power | 50-200W | - |
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- KEF R5 Meta vs KEF Reference 203
- KEF Reference 203 vs KEF R11 Meta
The Two Speakers In Full
KEF Reference 203: $5000 Discontinued
Pros: An unusually accomplished 4-way design for its era: excellent on-axis linearity (within about +/-3dB), genuinely good directivity both horizontally (~55 degrees) and vertically (~40-50 degrees), and an estimated in-room response that closely matches what the reviewer actually heard. Distortion is excellent - under 1% harmonic above 80Hz at both 86dB and 96dB, and multitone stays around 1% even at 96dB. Bass reaches a real F3 of 51Hz (F10 37Hz), with in-room extension into the low-mid-40s. The reviewer’s overall listening notes were essentially “nothing stood out bad or good” - a genuinely neutral, accurate speaker with a distinctive rounded-baffle look that avoids the diffraction issues a flat baffle this wide would normally have.
Cons: This is a 20+ year old, long-discontinued speaker only findable secondhand (Facebook Marketplace, Craigslist, audio forums) - condition, driver matching, and component aging vary by unit, so audition before buying if at all possible. Demands a robust amplifier: impedance dips to about 3.6 ohms with an EPDR of 2.2 ohms. The small supertweeter shows minor breakup artifacts at the extremes of the vertical polar plot and some compression at very high output in the top octave, though neither was audible in normal listening. Discontinued.
Full KEF Reference 203 review and specifications →
| Bass Extension (-10dB) | 37Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 51Hz (measured, Erin's Audio Corner) |
| Crossover Frequency | 400Hz, 2.7kHz, 15kHz |
| Dimensions | 1067H mm (42" tall) |
| Discontinued | Yes |
| Drivers | 1x 0.75" supertweeter, coaxial 1" dome tweeter + 6.5" midrange, 2x 6.5" woofers |
| Frequency Response | 55Hz - 55kHz ±3dB (Manufacturer specified) |
| Impedance | 8 ohms nominal (3.6 ohms minimum, measured, Erin's Audio Corner; 3.2 ohms per manufacturer spec) |
| Recommended Power | 50-200W |
| Sensitivity | 88dB (2.83V/1m, measured by Erin's Audio Corner) |
| Weight | 58 lbs / 26.3 kg (58 lb) |
| Woofer Cabinet | Bass reflex, with switchable flat/cut/lifted bass ports for wall placement |
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JBL HDI-3600: $3800 Audioadvice
Pros: CEA2034 spinorama shows a fairly even on-axis response and flat overall frequency response, with high 90dB sensitivity and very low distortion through the midrange. Triple 6.5” Advanced Aluminum Matrix woofers and a 1” compression driver in JBL’s HDI waveguide.
Cons: A wide shelving-down above 2kHz affects the in-room response, and vertical dispersion is a bigger issue than horizontal - the reviewer noted the dip is wider here than on the smaller HDI-1600, making it more audible. Narrow vertical sweet spot means careful listener-height positioning matters more than usual.
Full JBL HDI-3600 review and specifications →
| Bass Extension (-10dB) | 62Hz - the on-axis curve also shows an unusual step/dip around 40-55Hz that may be a near-field-scan artifact for this tower (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 78Hz - the on-axis curve also shows an unusual step/dip around 40-55Hz that may be a near-field-scan artifact for this tower (measured, Audio Science Review) |
| Dimensions | 40.5"H x 10.2"W x 13.5"D (1029 x 260 x 343 mm) |
| Drivers | 2410H-2 1" compression driver, 3x 6.5" Advanced Aluminum Matrix woofers |
| Frequency Response | 38Hz - 30kHz (+/-3dB) (Manufacturer specified) |
| Impedance | 4 ohms nominal |
| Sensitivity | 89.5dB (2.83V/1m, measured, Audio Science Review) |
| Weight | 61.7 lbs / 28 kg each |
| Woofer Cabinet | ported, dual rear-firing |
As an eBay Partner, we may be compensated if you make a purchase.
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- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons