Short answer: the Ascend CBM-170 SE2. It ranks #66 of 130 bookshelf speakers by sound quality at $468; the GR-Research X-LS Encore ranks #83 and costs $1300, so there is little reason to consider the other one.
What the Ascend CBM-170 SE2 offers: On-axis response is impressively flat from about 100Hz to 2kHz, staying within roughly ±1dB, with a clean, gradual bass rolloff below that. The directivity index rises smoothly and predictably through the crossover region, and the estimated in-room response shows a smooth, consistent downward tilt from 100Hz to 10kHz with no major discontinuities - close to the ideal in-room target shape. Measured sensitivity of 86.8dB nearly matches Ascend’s 87dB spec. The manufacturer’s own preference-score modeling comes out to 5.81 unequalized (rising to 8.17 with an ideal subwoofer, or 6.33/8.41 with EQ applied) - a strong result for a compact 2-way, and a clear step up from the original CBM-170 SE this replaces. 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. High-frequency directivity narrows substantially above 10kHz, typical for a small dome tweeter, so the top octave will sound more reserved off-axis than on-axis. Bass rolls off as expected for a compact 2-way monitor: -3dB around 70Hz and -10dB around 50Hz, so a subwoofer is needed for full-range use. This data comes from the manufacturer’s own Klippel measurements rather than an independent third-party review, so there’s no outside verification of channel matching, distortion, or unit-to-unit consistency.
What the GR-Research X-LS Encore offers: An amazing value, especially if you managed to snag one of these built by AV123 in the early 2000s for $200-300. CEA2034 spinorama shows a generally flat on-axis response, especially in the listening window. Predicted in-room response is generally smooth and on-target. Distortion at 86dB SPL/1m is pretty clean above 200Hz. Watch for: A slight depression in the upper bass and some peaking in the lower bass shows up on-axis, along with directivity error in the crossover region. Vertical directivity requires staying within about 20 degrees of the tweeter axis. At 96dB SPL/1m distortion becomes “rather unhappy,” with bass distortion, a possible woofer issue around 2kHz, and a tweeter problem above 7kHz. As a DIY kit, it requires building the cabinet and crossover yourself.
Buy the Ascend CBM-170 SE2. It ranks higher for sound quality than the GR-Research X-LS Encore and costs less, which settles it without a real tradeoff to make.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| Ascend CBM-170 SE2 | GR-Research X-LS Encore | |
|---|---|---|
| Price | $468 per pair | $1300 per pair |
| Ranked | #66 of 130 in Large Size Bookshelf Speakers | #83 of 130 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; 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 | 5.81 | - |
| Spinorama Preference Score with Perfect Sub | 8.17 | - |
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Prices on this page were last checked September 16, 2026 at 12:41 AM 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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The Two Speakers In Full
Ascend CBM-170 SE2: $468 per pair Ascend Acoustics eBay
Pros: On-axis response is impressively flat from about 100Hz to 2kHz, staying within roughly ±1dB, with a clean, gradual bass rolloff below that. The directivity index rises smoothly and predictably through the crossover region, and the estimated in-room response shows a smooth, consistent downward tilt from 100Hz to 10kHz with no major discontinuities - close to the ideal in-room target shape. Measured sensitivity of 86.8dB nearly matches Ascend’s 87dB spec. The manufacturer’s own preference-score modeling comes out to 5.81 unequalized (rising to 8.17 with an ideal subwoofer, or 6.33/8.41 with EQ applied) - a strong result for a compact 2-way, and a clear step up from the original CBM-170 SE this replaces. Measured sensitivity of 86.8dB.
Cons: 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. High-frequency directivity narrows substantially above 10kHz, typical for a small dome tweeter, so the top octave will sound more reserved off-axis than on-axis. Bass rolls off as expected for a compact 2-way monitor: -3dB around 70Hz and -10dB around 50Hz, so a subwoofer is needed for full-range use. This data comes from the manufacturer’s own Klippel measurements rather than an independent third-party review, so there’s no outside verification of channel matching, distortion, or unit-to-unit consistency.
Full Ascend CBM-170 SE2 review and specifications →
| Bass Extension (-10dB) | 50Hz (measured, manufacturer spinorama data) |
|---|---|
| Bass Extension (-3dB) | 70Hz (measured, manufacturer spinorama data) |
| Dimensions | 12H x 9W x 9.5D in |
| Drivers | 27mm custom SEAS soft dome tweeter, 6.5" proprietary composite polygel cone woofer |
| Impedance | 8 ohms |
| Power Handling | 200W continuous, 400W peak |
| Sensitivity | 86.8dB (2.83V/1m, measured, manufacturer spinorama data; 87dB manufacturer specified) |
| Spinorama Preference Score | 5.81 |
| Spinorama Preference Score with Perfect Sub | 8.17 |
| Weight | 15 lbs (6.8 kg) each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Ascend CBM-170 SE2 vs Polk Signature Elite ES20
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- Ascend CBM-170 SE2 vs Dynaudio Emit 20
- Ascend CBM-170 SE2 vs Philharmonic BMR Monitor
- Ascend CBM-170 SE2 vs ELAC DBR62
- Ascend CBM-170 SE2 vs Mission LX-3 MKII
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- See all 44 comparisons
GR-Research X-LS Encore: $1300 per pair Gr-research eBay
Pros: An amazing value, especially if you managed to snag one of these built by AV123 in the early 2000s for $200-300. CEA2034 spinorama shows a generally flat on-axis response, especially in the listening window. Predicted in-room response is generally smooth and on-target. Distortion at 86dB SPL/1m is pretty clean above 200Hz. Measured bass extension of 64Hz (-3dB), with a measured sensitivity of 84.4dB.
Cons: A slight depression in the upper bass and some peaking in the lower bass shows up on-axis, along with directivity error in the crossover region. Vertical directivity requires staying within about 20 degrees of the tweeter axis. At 96dB SPL/1m distortion becomes “rather unhappy,” with bass distortion, a possible woofer issue around 2kHz, and a tweeter problem above 7kHz. As a DIY kit, it requires building the cabinet and crossover yourself.
Full GR-Research X-LS Encore review and specifications →
| Bass Extension (-10dB) | 44Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 64Hz (measured, Audio Science Review) |
| Dimensions | 13.5"H x 8.5"W x 12.1"D (342.9 x 215.9 x 308 mm) |
| Drivers | 6.5" Peerless M-165 paper composite cone, non-resonant polymer frame woofer, 1" Peerless India T26SG tweeter |
| Impedance | 8 ohms |
| Sensitivity | 84.4dB (measured by Audio Science Review; 87dB manufacturer specified) |
| Weight | 17 lbs (7.7 kg) each |
| Woofer Cabinet | ported |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- GR-Research X-LS Encore vs Dynaudio Special Forty
- GR-Research X-LS Encore vs Mission LX-3 MKII
- GR-Research X-LS Encore vs ELAC Debut 2.0 B6.2
- GR-Research X-LS Encore vs SVS Prime Bookshelf
- GR-Research X-LS Encore vs KEF Q3 Meta
- GR-Research X-LS Encore vs Polk Monitor XT20
- GR-Research X-LS Encore vs Philharmonic BMR Monitor
- GR-Research X-LS Encore vs Sonus Faber Lumina II
- See all 47 comparisons