Short answer: the AsciLab C6B. It ranks #6 of 222 bookshelf speakers by sound quality, rated 4.7/5, at $1,145. The Ascend Acoustics CBM-170 SE2 ranks #114, rated 3.8/5, at $468, $677 cheaper, which does not close the gap in sound quality.
The AsciLab C6B is the better-sounding, deeper-bass pick. Two-way design pairing a 1” aluminum ceramic dome tweeter on a large waveguide with a 6” aluminum ceramic cone woofer, crossed over at 1.1kHz, plus a rear passive radiator. Its bass reaches about 54Hz before falling 3dB, against 70Hz for the Ascend Acoustics CBM-170 SE2. The tradeoff: Bass rolls off around 50Hz in-room (F3 54Hz, F10 35Hz), so a subwoofer is needed for real extension below that.
Why pick the Ascend Acoustics CBM-170 SE2: On-axis response is impressively flat from about 100Hz to 2kHz, staying within roughly ±1dB, with a clean, gradual bass rolloff below that. Watch for: A narrow dip in the on-axis and listening-window response appears in the 3-5kHz range (down to about -2.7dB), mirrored by a matching dip in the directivity index at the same frequencies: likely a brief widening of dispersion right at the tweeter/woofer crossover.
Buy the AsciLab C6B. It is rated higher for sound quality, and the $677 you would save on the Ascend Acoustics CBM-170 SE2 does not close the gap.
Looking for alternatives? See the complete Passive Home rankings.
Two-way design pairing a 1” aluminum ceramic dome tweeter on a large waveguide with a 6” aluminum ceramic cone woofer, crossed over at 1.1kHz, plus a rear passive radiator.
Ascilab $1145 eBay
On-axis response is impressively flat from about 100Hz to 2kHz, staying within roughly ±1dB, with a clean, gradual bass rolloff below that.
Ascend Acoustics $468 eBayPrices on this page were last checked October 17, 2026 at 6:04 PM 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.
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Specifications Side By Side
| AsciLab C6B | Ascend Acoustics CBM-170 SE2 | |
|---|---|---|
| Price | $1145 per pair | $468 per pair |
| Ranked | #6 of 222 in Large Size Bookshelf Speakers | #114 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 35Hz (measured, Erin’s Audio Corner) | 50Hz (measured, manufacturer spinorama data) |
| Bass Extension (-3dB) | 54Hz (measured, Erin’s Audio Corner) | 70Hz (measured, manufacturer spinorama data) |
| Dimensions | 15.7”H x 8”W x 10.4”D (398.8 x 203.2 x 264.2 mm) | 12H x 9W x 9.5D in |
| Impedance | 4 ohms nominal, 2.6 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms |
| Sensitivity | 85.6dB (measured, Erin’s Audio Corner) | 86.8dB (2.83V/1m, measured, manufacturer spinorama data; 87dB manufacturer specified) |
| Drivers | 6” Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1” Aluminium Ceramic Dome tweeter | 27mm custom SEAS soft dome tweeter, 6.5” proprietary composite polygel cone woofer |
| Weight | 18.5 lbs (8.4 kg) each | 15 lbs (6.8 kg) each |
| Woofer Cabinet | passive radiator | ported, rear |
| Spinorama Preference Score | 6.33 | 6.30 |
| Spinorama Preference Score with Perfect Sub | 8.28 | 8.66 |
| DIY Kit | No | No |
| Power Handling | - | 200W continuous, 400W peak |
Frequency Response Compared
Both speakers’ spinorama measurements, overlaid. A flatter line is more neutral: peaks sound forward or harsh, dips sound recessed. Each curve is shifted so its average from 300 Hz to 3 kHz sits at 0 dB, so loudness differences between the two are removed and only the shape is compared. The two were measured by different sources, so small differences, especially in the bass, can come from the measurement setup rather than the speakers.
Measurement data: AsciLab C6B (measured by Erin’s Audio Corner) and Ascend Acoustics CBM-170 SE2 (measured by the manufacturer), via spinorama.org.
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