Short answer: the Ascend Acoustics CBM-170 SE2. It ranks #113 of 222 bookshelf speakers by sound quality, rated 3.8/5, at $468; the Dynaudio Special Forty ranks #148, rated 3.5/5, and costs $3,600, so there is little reason to consider the other one.
The Ascend Acoustics CBM-170 SE2 is the more accurate option. 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 4.73 for the Dynaudio Special Forty. 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 Dynaudio Special Forty is the deeper-bass choice. Premium bookshelf speakers with strong output, wide dispersion and fairly deep bass from a compact rear ported cabinet. Its bass reaches about 54Hz before falling 3dB, against 70Hz for the Ascend Acoustics CBM-170 SE2. Watch for: A glaring, sometimes sibilant quality around 3-4kHz was the most noticeable issue in listening, the one thing the reviewer would want notched out with EQ.
Buy the Ascend Acoustics CBM-170 SE2. It is rated higher for sound quality than the Dynaudio Special Forty and costs less, so only choose the other one for a particular feature it does better.
Looking for alternatives? See the complete Passive Home rankings.
Compact two-way bookshelf speakers with a SEAS tweeter, a very flat midrange and smooth sound that suits most rooms.
Premium bookshelf speakers with strong output, wide dispersion and fairly deep bass from a compact rear ported cabinet.
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Specifications Side By Side
| Ascend Acoustics CBM-170 SE2 | Dynaudio Special Forty | |
|---|---|---|
| Price | $468 per pair | $3600 per pair |
| Ranked | #113 of 222 in Large Size Bookshelf Speakers | #148 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 70Hz (measured, manufacturer spinorama data) | 54Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | 50Hz (measured, manufacturer spinorama data) | 39Hz (measured, Erin’s Audio Corner) |
| Sensitivity | 86.8dB (2.83V/1m, measured, manufacturer spinorama data; 87dB manufacturer specified) | 83.5dB (measured, Erin’s Audio Corner; 86dB manufacturer specified) |
| Drivers | 27mm custom SEAS soft dome tweeter, 6.5” proprietary composite polygel cone woofer | 5.9” MSP (Magnesium Silicate Polymer) cone woofer, 1” Esotar soft dome tweeter |
| Dimensions | 12H x 9W x 9.5D in | 14.1”H x 7.7”W x 12.1”D (358.1 x 195.6 x 307.3 mm) |
| Weight | 15 lbs (6.8 kg) each | 17.9 lbs (8.1 kg) each |
| Impedance | 8 ohms | 6 ohms nominal (4.9 ohms minimum above 80Hz, measured, Erin’s Audio Corner) |
| Power Handling | 200W continuous, 400W peak | - |
| Woofer Cabinet | ported, rear | ported |
| Spinorama Preference Score | 6.30 | 4.73 |
| Spinorama Preference Score with Perfect Sub | 8.66 | 6.74 |
| DIY Kit | No | No |
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