Short answer: the AsciLab F6Bs. It ranks #20 of 222 bookshelf speakers by sound quality (rated 4.5/5); the Ascend Acoustics CBM-170 SE2 ranks #114 (rated 3.8/5).
The Ascend Acoustics CBM-170 SE2 is the more accurate, deeper-bass pick. On-axis response is impressively flat from about 100Hz to 2kHz, staying within roughly ±1dB, with a clean, gradual bass rolloff below that. Its measured preference score, a predictor of how neutral it sounds, is 6.30 against 5.24 for the AsciLab F6Bs. Its bass reaches about 70Hz before falling 3dB, against 82Hz for the AsciLab F6Bs. 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.
The AsciLab F6Bs is the better-sounding choice. A slimmer, sealed, VESA 100 wall mountable variant of the AsciLab F6B, trading the AsciLab F6B’s passive radiator for a shallower 15.4cm deep cabinet that can go straight on a wall bracket. The catch: AsciLab’s own site shows the F6Bs sold out, though it remains in stock through resellers like Audiophonics and Tested Audio.
Buy the AsciLab F6Bs. It is rated higher for sound quality than the Ascend Acoustics CBM-170 SE2.
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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 eBay
A slimmer, sealed, VESA 100 wall mountable variant of the AsciLab F6B, trading the AsciLab F6B’s passive radiator for a shallower 15.4cm deep cabinet that can go straight on a wall bracket.
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Specifications Side By Side
| Ascend Acoustics CBM-170 SE2 | AsciLab F6Bs | |
|---|---|---|
| Price | $468 per pair | €799 per pair |
| Ranked | #114 of 222 in Large Size Bookshelf Speakers | #20 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 70Hz (measured, manufacturer spinorama data) | 82.0Hz (measured, Audio Science Review) |
| Bass Extension (-10dB) | 50Hz (measured, manufacturer spinorama data) | 50.1Hz (measured, Audio Science Review) |
| Sensitivity | 86.8dB (2.83V/1m, measured, manufacturer spinorama data; 87dB manufacturer specified) | 85.2dB @ 2.83V/1m (measured, Audio Science Review) |
| Drivers | 27mm custom SEAS soft dome tweeter, 6.5” proprietary composite polygel cone woofer | 1” aluminum dome tweeter with waveguide and phase plug, 6” fiber cone woofer |
| Dimensions | 12H x 9W x 9.5D in | 14.5”H x 8”W x 6.1”D (368 x 203 x 154 mm) |
| Weight | 15 lbs (6.8 kg) each | 12.3 lbs (5.6 kg) each |
| Impedance | 8 ohms | 4 ohms nominal, 3.7 ohms minimum |
| Power Handling | 200W continuous, 400W peak | - |
| Woofer Cabinet | ported, rear | - |
| Spinorama Preference Score | 6.30 | 5.24 |
| Spinorama Preference Score with Perfect Sub | 8.66 | 7.90 |
| DIY Kit | No | No |
| Enclosure | - | sealed |
| Crossover Frequency | - | 1kHz |
| Mounting | - | VESA 100 wall mount compatible |
| Warranty | - | 2 years |
| Country | - | South Korea |
| Maximum SPL | - | 100dB full bandwidth, 102dB above 100Hz (manufacturer specified) |
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: Ascend Acoustics CBM-170 SE2 (measured by the manufacturer) and AsciLab F6Bs (measured by Audio Science Review), via spinorama.org.
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