Short answer: the Emotiva Airmotiv XB2. It ranks #48 of 222 bookshelf speakers by sound quality, rated 4.2/5, at $549. The Ascend Acoustics CBM-170 SE2 ranks #113, rated 3.8/5, at $468, $81 cheaper, a saving that is not big enough to make up the sound-quality gap.
The Ascend Acoustics CBM-170 SE2 is the more accurate choice. Compact two-way bookshelf speakers with a SEAS tweeter, a very flat midrange and smooth sound that suits most rooms. Its measured preference score, a predictor of how neutral it sounds, is 6.30 against 5.65 for the Emotiva Airmotiv XB2. 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 Emotiva Airmotiv XB2 is the better-sounding, deeper-bass option. A great value bookshelf speaker with neutral sound, an AMT ribbon tweeter, and decent bass for its size. Its bass reaches about 62Hz before falling 3dB, against 70Hz for the Ascend Acoustics CBM-170 SE2. The tradeoff: Slight recessed upper-midrange around 2kHz from the tweeter-to-woofer handoff.
Buy the Emotiva Airmotiv XB2. It is rated higher for sound quality, and saving $81 with the Ascend Acoustics CBM-170 SE2 does not make up for the sound-quality gap.
Still deciding? The full Passive Home rankings cover every ranked option.
Compact two-way bookshelf speakers with a SEAS tweeter, a very flat midrange and smooth sound that suits most rooms.
A great value bookshelf speaker with neutral sound, an AMT ribbon tweeter, and decent bass for its size.
Prices on this page were last checked October 31, 2026 at 7:11 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
| Ascend Acoustics CBM-170 SE2 | Emotiva Airmotiv XB2 | |
|---|---|---|
| Price | $468 per pair | $549 per pair |
| Ranked | #113 of 222 in Large Size Bookshelf Speakers | #48 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 70Hz (measured, manufacturer spinorama data) | 62Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | 50Hz (measured, manufacturer spinorama data) | 43Hz (measured, Erin’s Audio Corner) |
| Sensitivity | 86.8dB (2.83V/1m, measured, manufacturer spinorama data; 87dB manufacturer specified) | 86dB (2.83V/1m, Manufacturer specified) |
| Drivers | 27mm custom SEAS soft dome tweeter, 6.5” proprietary composite polygel cone woofer | 1x 6” woven cone woofer, 1x 25x32mm AMT folded ribbon tweeter |
| Dimensions | 12H x 9W x 9.5D in | 12.8” x 8.5” x 11.5” (325 x 216 x 292 mm) |
| Weight | 15 lbs (6.8 kg) each | 18.1 lbs (8.2 kg) |
| Impedance | 8 ohms | 4 ohms nominal (safe with 8-ohm rated amps) |
| Power Handling | 200W continuous, 400W peak | 125W continuous, 200W peak |
| Woofer Cabinet | ported, rear | Bass reflex, rear ported |
| Spinorama Preference Score | 6.30 | 5.65 |
| Spinorama Preference Score with Perfect Sub | 8.66 | 7.93 |
| DIY Kit | No | No |
| Frequency Response | - | 48Hz - 27kHz (+3/-3dB, Manufacturer specified) |
| Crossover Frequency | - | 2.6kHz |
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