Short answer: the Ascend Acoustics CBM-170 SE2. It ranks #114 of 222 bookshelf speakers by sound quality, rated 3.8/5, at $468; the GR-Research X-LS Encore ranks #146, rated 3.5/5, and costs $1,300, so there is little reason to consider the other one.
The CBM-170 SE2 is the better-measuring, ready-built speaker. Ascend’s own Klippel data shows a very flat on-axis response from 100Hz to 2kHz, a smooth in-room tilt close to the ideal target and a preference score of 6.30. It has a small dip from 3 to 5kHz and reserved top-octave treble off-axis. Its bass falls 3dB at 70Hz, so a subwoofer helps.
The X-LS Encore is a DIY kit with deeper bass. Its Peerless woofer reaches 64Hz before falling 3dB, and Audio Science Review found a flat listening window and smooth predicted in-room response. You build the cabinet and crossover yourself, stay within about 20 degrees of the tweeter vertically, and distortion rises sharply at 96dB.
Buy the Ascend Acoustics CBM-170 SE2. It is rated higher for sound quality than the GR-Research X-LS Encore and costs less, so only choose the other one for a particular feature it does better.
Still deciding? The full Passive Home rankings cover every ranked option.
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
An amazing value for a speaker that measures this well.
GR Research $1300 eBayPrices on this page were last checked October 16, 2026 at 5:46 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 | GR-Research X-LS Encore | |
|---|---|---|
| Price | $468 per pair | $1300 per pair |
| Ranked | #114 of 222 in Large Size Bookshelf Speakers | #146 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 70Hz (measured, manufacturer spinorama data) | 64Hz (measured, Audio Science Review) |
| Bass Extension (-10dB) | 50Hz (measured, manufacturer spinorama data) | 44Hz (measured, Audio Science Review) |
| Sensitivity | 86.8dB (2.83V/1m, measured, manufacturer spinorama data; 87dB manufacturer specified) | 84.4dB (measured by Audio Science Review on the kit; 87dB manufacturer specified) |
| Drivers | 27mm custom SEAS soft dome tweeter, 6.5” proprietary composite polygel cone woofer | 6.5” Peerless M-165 paper composite cone, non-resonant polymer frame woofer, 1” Peerless India T26SG tweeter |
| Dimensions | 12H x 9W x 9.5D in | 13.5”H x 8.5”W x 12.1”D (342.9 x 215.9 x 308 mm) |
| Weight | 15 lbs (6.8 kg) each | 17 lbs (7.7 kg) each |
| Impedance | 8 ohms | 8 ohms |
| Power Handling | 200W continuous, 400W peak | - |
| Woofer Cabinet | ported, rear | ported |
| Spinorama Preference Score | 6.30 | 5.05 (measured, spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 8.66 | 7.42 (measured, spinorama.org) |
| DIY Kit | No | - |
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 GR-Research X-LS Encore (measured by Audio Science Review), via spinorama.org.
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