Short answer: the Atlantic Technology 8600iLR, if you are buying new. The Atlantic Technology 8600eLR ranks higher than the Klipsch Heresy IV (#204 vs #222 of 228 floorstanding speakers) but is discontinued; its replacement, the Atlantic Technology 8600iLR, is rated 3.2/5 at $6,000 and is still sold new.
The Atlantic Technology 8600eLR is the better-sounding, deeper-bass choice. A massive sealed tower with four 8 inch woofers, high sensitivity and boundary controls, now discontinued. Its bass reaches about 68.8Hz before falling 3dB, against 77Hz for the Klipsch Heresy IV. The tradeoff: The raw preference score is only 2.65, making a subwoofer and correction essential despite the massive cabinet.
Why pick the Klipsch Heresy IV: A compact horn loaded speaker with a 12 inch woofer and very high sensitivity, giving lively dynamics from modest amplifiers. The tradeoff: Erin measured a 77Hz F3 and response rolling away near 100Hz in-room, so a subwoofer is required for modern full-range reproduction.
Buy the Atlantic Technology 8600iLR, the replacement for the discontinued Atlantic Technology 8600eLR; it is rated higher for sound quality than the Klipsch Heresy IV.
Want more options? Browse the full Passive Home rankings.
Measured Differences
- Efficiency: the Klipsch Heresy IV is rated at 94.5 dB sensitivity against 91 dB for the Atlantic Technology 8600eLR, so it plays as loud with roughly half the amplifier power.
- Close enough not to matter: bass extension (47.6 Hz vs 50 Hz, 10 dB down); preference score with a subwoofer (5.3 vs 5.0).
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Specifications Side By Side
| Atlantic Technology 8600eLR | Klipsch Heresy IV | |
|---|---|---|
| Price | $5,700 per pair Discontinued | $3,599.98 per pair |
| Ranked | #204 of 228 in Large Size Floorstanding Speakers | #222 of 228 in Large Size Floorstanding Speakers |
| Bass Extension (-10dB) | about 47.6Hz (measured, Erin’s Audio Corner) | 50.0Hz (measured, Erin’s Audio Corner) |
| Enclosure | Sealed 3-way floorstander | - |
| Drivers | 1-inch aluminum-magnesium tweeter, dual 5.25-inch midranges, four 8-inch woofers | 1” horn-loaded tweeter; 1.75” horn-loaded midrange; 12” woofer |
| Frequency Response | 50Hz-25kHz +/-2dB | - |
| Sensitivity | 91dB | 94.5dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Impedance | 6 ohms | Approximately 4 ohms minimum (measured, Erin’s Audio Corner) |
| Dimensions | 51.7H x 10.9W x 11.4D in | 24.8”H x 15.6”W x 13.3”D |
| Weight | 93.3 lbs (42.3 kg) each | 45 lbs (20.4 kg) each |
| Spinorama Preference Score | 2.65 | 2.27 |
| Spinorama Preference Score with Perfect Sub | 5.26 | 5.02 |
| Bass Extension (-3dB) | 68.8Hz (measured, Erin’s Audio Corner via spinorama.org) | 77Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No | No |
| Woofer Cabinet | - | ported, rear |
Where the Ratings Come From
- Atlantic Technology 8600eLR: Spinorama.org measurements and reviews by AVS.
- Klipsch Heresy IV: Spinorama.org measurements and reviews by Erin’s Audio Corner.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
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