Short answer: the AsciLab A6B Passive. It ranks #18 of 222 bookshelf speakers by sound quality (rated 4.5/5); the Klipsch RP-600M II ranks #123 (rated 3.7/5).
What the Klipsch RP-600M II does well: Bookshelf speakers with a large horn tweeter, wide soundstage, high efficiency and bi-amp ready terminals. Watch for: On-axis, the treble runs notably hot (even hotter than the original Klipsch RP-600M in some respects) and needs about 20° of toe-out or the grille installed to sound balanced.
The AsciLab A6B Passive is the more accurate, deeper-bass option. A sealed bookshelf speaker with a Purifi woofer and passive radiators, essentially flat response, and solid bass for its size. Its measured preference score, a predictor of how neutral it sounds, is 6.50 against 5.64 for the Klipsch RP-600M II. Its bass reaches about 41Hz before falling 3dB, against 70Hz for the Klipsch RP-600M II. Watch for: 4 ohm nominal impedance and 82dB sensitivity call for a robust amplifier.
Buy the AsciLab A6B Passive. It is rated higher for sound quality than the Klipsch RP-600M II.
Still deciding? The full Passive Home rankings cover every ranked option.
Bookshelf speakers with a large horn tweeter, wide soundstage, high efficiency and bi-amp ready terminals.
A sealed bookshelf speaker with a Purifi woofer and passive radiators, essentially flat response, and solid bass for its size.
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Specifications Side By Side
| Klipsch RP-600M II | AsciLab A6B Passive | |
|---|---|---|
| Price | $449.99 per pair | €3,790 per pair |
| Ranked | #123 of 222 in Large Size Bookshelf Speakers | #18 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 41Hz (measured, Erin’s Audio Corner) | 34.7Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 70Hz (measured, Erin’s Audio Corner) | 41.0Hz (measured, Audio Science Review) |
| Dimensions | 15.7”H x 8”W x 12.5”D (398.8 x 203.2 x 317.5 mm) | 15.9”H x 8.7”W x 11.8”D (405 x 220 x 300 mm) |
| Impedance | 8 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin’s Audio Corner) | 4 ohms nominal |
| Sensitivity | 86dB (measured, Erin’s Audio Corner) | 82dB @ 2.83V/1m |
| Drivers | 6.5” Cerametallic cone woofer, 1” titanium LTS vented tweeter with Tractrix horn | 1” dome tweeter, 6.5” Purifi aluminum cone woofer, 2x 6.5” Purifi passive radiators |
| Weight | 13 lbs (5.9 kg) each | 27.1 lbs (12.3 kg) each |
| Woofer Cabinet | ported | - |
| Spinorama Preference Score | 5.64 | 6.50 |
| Spinorama Preference Score with Perfect Sub | 7.77 | 8.24 |
| DIY Kit | No | No |
| Enclosure | - | sealed with passive radiators |
| Crossover Frequency | - | 1kHz |
| Warranty | - | 2 years |
| Country | - | South Korea |
| Maximum SPL | - | 102dB full bandwidth, 106dB above 100Hz (manufacturer specified) |
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