Short answer: the JBL HDI-3600 for better sound quality, the Klipsch Heresy IV for the lower price. The JBL HDI-3600 ranks #28 of 68 floorstanding speakers at $3800. The Klipsch Heresy IV ranks #44 at $3198, $602 cheaper.
What the JBL HDI-3600 offers: 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. Watch for: 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.
What the Klipsch Heresy IV offers: Very high 94.5dB/2.83V/1m sensitivity in Erin’s anechoic measurement—well below Klipsch’s 99dB in-room claim, but still excellent—and strong short-term output from a 12-inch woofer plus horn-loaded midrange and tweeter. The compact, furniture-grade Heritage cabinet is easier to place than most high-efficiency designs, and dynamics at moderate levels can sound lively. A stable four-ohm-capable amplifier can produce substantial SPL with relatively little voltage. Watch for: Erin measured a 77Hz F3 and response rolling away near 100Hz in-room, so a subwoofer is required for modern full-range reproduction. The impedance dips to about 4 ohms, reducing the practical amplifier advantage implied by its sensitivity. Pronounced directivity mismatch at the driver transitions, impedance/response resonances and elevated distortion spikes around the crossover remain audible concerns that EQ cannot fully solve. At 102dB Erin measured roughly 1.5dB midband compression; at 96dB distortion rises around crossover. Performance is difficult to justify at the price, and Erin explicitly did not recommend it.
Buy the JBL HDI-3600 if sound quality matters more than the price. Buy the Klipsch Heresy IV if the price matters more than sound quality.
Specifications Side By Side
| JBL HDI-3600 | Klipsch Heresy IV | |
|---|---|---|
| Price | $3800 | $3,198/pair |
| Ranked | #28 of 68 in Large Size Floorstanding Speakers | #44 of 68 in Large Size Floorstanding Speakers |
| 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) | 77Hz (measured, Erin’s Audio Corner) |
| 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) | 50.0Hz (measured, Erin’s Audio Corner) |
| Sensitivity | 89.5dB (2.83V/1m, measured, Audio Science Review) | 94.5dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Impedance | 4 ohms nominal | Approximately 4 ohms minimum (measured, Erin’s Audio Corner) |
| Frequency Response | 38Hz - 30kHz (+/-3dB) (Manufacturer specified) | - |
| Drivers | 2410H-2 1" compression driver, 3x 6.5" Advanced Aluminum Matrix woofers | 1" horn-loaded tweeter; 1.75" horn-loaded midrange; 12" woofer |
| Weight | 61.7 lbs / 28 kg each | 45 lb each |
| Dimensions | 40.5"H x 10.2"W x 13.5"D (1029 x 260 x 343 mm) | 24.8"H x 15.6"W x 13.3"D |
| Woofer Cabinet | ported, dual rear-firing | ported, rear |
Related Speaker Comparisons
More useful head-to-heads from the same speaker class:
- Klipsch Forte IV vs Polk Audio XT60
- JBL HDI-3800 vs Revival Audio Atalante 5
- MoFi SourcePoint 888 vs Revival Audio Atalante 5
- KEF R5 vs JBL HDI-3600
- KEF R11 Meta vs JBL HDI-3600
Prices on this page were last checked August 24, 2026 at 6:53 AM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Speakers In Full
JBL HDI-3600: $3800 Audioadvice eBay
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 |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Klipsch Heresy IV: $3,198/pair Amazon Crutchfield eBay
Pros: Very high 94.5dB/2.83V/1m sensitivity in Erin’s anechoic measurement—well below Klipsch’s 99dB in-room claim, but still excellent—and strong short-term output from a 12-inch woofer plus horn-loaded midrange and tweeter. The compact, furniture-grade Heritage cabinet is easier to place than most high-efficiency designs, and dynamics at moderate levels can sound lively. A stable four-ohm-capable amplifier can produce substantial SPL with relatively little voltage.
Cons: Erin measured a 77Hz F3 and response rolling away near 100Hz in-room, so a subwoofer is required for modern full-range reproduction. The impedance dips to about 4 ohms, reducing the practical amplifier advantage implied by its sensitivity. Pronounced directivity mismatch at the driver transitions, impedance/response resonances and elevated distortion spikes around the crossover remain audible concerns that EQ cannot fully solve. At 102dB Erin measured roughly 1.5dB midband compression; at 96dB distortion rises around crossover. Performance is difficult to justify at the price, and Erin explicitly did not recommend it.
Full Klipsch Heresy IV review and specifications →
| Bass Extension (-10dB) | 50.0Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 77Hz (measured, Erin's Audio Corner) |
| Dimensions | 24.8"H x 15.6"W x 13.3"D |
| Drivers | 1" horn-loaded tweeter; 1.75" horn-loaded midrange; 12" woofer |
| Impedance | Approximately 4 ohms minimum (measured, Erin's Audio Corner) |
| Sensitivity | 94.5dB/2.83V/1m (measured, Erin's Audio Corner) |
| Weight | 45 lb each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Klipsch Heresy IV vs Polk Audio XT60
- Klipsch Heresy IV vs KEF Q11 Meta
- Klipsch Heresy IV vs Klipsch Forte IV
- Klipsch Heresy IV vs Infinity Primus 360
- Klipsch Heresy IV vs Klipsch RP-5000F II
- Klipsch Heresy IV vs SVS Ultra Evolution Pinnacle
- Klipsch Heresy IV vs Definitive Technology BP-9020
- Klipsch Heresy IV vs Polk Reserve R500
- See all 25 comparisons