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 Sierra-LX ranks #37, rated 4.3/5, and costs $1,598, so there is little reason to consider the other one.
The AsciLab C6B is the better-sounding option. Bookshelf speakers with very accurate sound and an unusually wide, stable soundstage, for any seating position. The tradeoff: Bass rolls off around 50Hz in-room (F3 54Hz, F10 35Hz), so a subwoofer is needed for real extension below that.
The Ascend Acoustics Sierra-LX is the deeper-bass option. A compact bookshelf speaker with very neutral, flat sound, a wide soundstage, and surprisingly deep bass in a bamboo cabinet. Its bass reaches about 47Hz before falling 3dB, against 54Hz for the AsciLab C6B. The catch: Very low sensitivity at about 81dB, so it needs a genuinely powerful amplifier to reach normal listening levels.
Buy the AsciLab C6B. It is rated higher for sound quality than the Ascend Acoustics Sierra-LX and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Still deciding? The full Passive Home rankings cover every ranked option.
Bookshelf speakers with very accurate sound and an unusually wide, stable soundstage, for any seating position.
A compact bookshelf speaker with very neutral, flat sound, a wide soundstage, and surprisingly deep bass in a bamboo cabinet.
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Specifications Side By Side
| AsciLab C6B | Ascend Acoustics Sierra-LX | |
|---|---|---|
| Price | $1145 per pair | $1598 per pair |
| Ranked | #6 of 222 in Large Size Bookshelf Speakers | #37 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 35Hz (measured, Erin’s Audio Corner) | 38Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | 54Hz (measured, Erin’s Audio Corner) | 47Hz (measured, Erin’s Audio Corner) |
| Dimensions | 15.7”H x 8”W x 10.4”D (398.8 x 203.2 x 264.2 mm) | 14.3” x 7.5” x 10.5” (362 x 191 x 267 mm) |
| Impedance | 4 ohms nominal, 2.6 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms nominal (5.5 ohms minimum) |
| Sensitivity | 85.6dB (measured, Erin’s Audio Corner) | 81dB (2.83V/1m, measured by Erin’s Audio Corner) |
| Drivers | 6” Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1” Aluminium Ceramic Dome tweeter | 6” aluminum cone woofer, 26mm dome tweeter |
| Weight | 18.5 lbs (8.4 kg) each | 20.9 lbs (9.5 kg) |
| Woofer Cabinet | passive radiator | Bass reflex, flared rear port |
| Spinorama Preference Score | 6.33 | 6.63 |
| Spinorama Preference Score with Perfect Sub | 8.28 | 8.44 |
| DIY Kit | No | No |
| Power Handling | - | 350W continuous, 500W peak |
| Frequency Response | - | 28Hz - 23kHz (in-room, manufacturer specified) |
| Country | - | USA |
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