Short answer: the Ascend Acoustics CBM-170 SE2. It ranks #112 of 216 bookshelf speakers by sound quality, rated 3.8/5, at $468; the ATC SCM19 ranks #203, rated 2.4/5, and costs $3,750, so there is little reason to consider the other one.
The Ascend Acoustics CBM-170 SE2 is the more accurate option. On-axis response is impressively flat from about 100Hz to 2kHz, staying within roughly ±1dB, with a clean, gradual bass rolloff below that. Its measured preference score, a predictor of how neutral it sounds, is 6.30 against 4.61 for the ATC SCM19. The tradeoff: 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 ATC SCM19 is the deeper-bass choice. Harmonic distortion at 96dB SPL/1m stays generally low across the range aside from the spike tied to the 700-800Hz resonance. Its bass reaches about 60Hz before falling 3dB, against 70Hz for the Ascend Acoustics CBM-170 SE2. Watch for: Some stored energy resonance around 500-700Hz, 4dB bump around 700Hz.
Buy the Ascend Acoustics CBM-170 SE2. It is rated higher for sound quality than the ATC SCM19 and costs less, so only choose the other one for a particular feature it does better.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| Ascend Acoustics CBM-170 SE2 | ATC SCM19 | |
|---|---|---|
| Price | $468 per pair | $3750 per pair |
| Ranked | #112 of 216 in Large Size Bookshelf Speakers | #203 of 216 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 70Hz (measured, manufacturer spinorama data) | 60Hz (measured, Audio Science Review) |
| Bass Extension (-10dB) | 50Hz (measured, manufacturer spinorama data) | 34Hz (measured, Audio Science Review) |
| Sensitivity | 86.8dB (2.83V/1m, measured, manufacturer spinorama data; 87dB manufacturer specified) | 85dB (measured, Audio Science Review) |
| Drivers | 27mm custom SEAS soft dome tweeter, 6.5” proprietary composite polygel cone woofer | 5.9” Super Linear Magnet cone woofer, 1” soft dome tweeter |
| Dimensions | 12H x 9W x 9.5D in | 17.2”H x 10.4”W x 11.8”D (436.9 x 264.2 x 299.7 mm) |
| Weight | 15 lbs (6.8 kg) each | 39.2 lbs (17.8 kg) each |
| Impedance | 8 ohms | 6 ohms |
| Power Handling | 200W continuous, 400W peak | - |
| Woofer Cabinet | ported, rear | sealed |
| Spinorama Preference Score | 6.30 | 4.61 |
| Spinorama Preference Score with Perfect Sub | 8.66 | 7.03 |
| DIY Kit | No | 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 ATC SCM19 (measured by Audio Science Review), via spinorama.org.
Related Speaker Comparisons
More top alternatives to Ascend Acoustics CBM-170 SE2:
- Ascend Acoustics CBM-170 SE2 vs Perlisten S4b
- Ascend Acoustics CBM-170 SE2 vs KEF Reference 1 Meta
- Ascend Acoustics CBM-170 SE2 vs GR-Research NX-Studio
- AsciLab C6B vs Ascend Acoustics CBM-170 SE2
- Ascend Acoustics CBM-170 SE2 vs Audio First Cadentia 3
Prices on this page were last checked October 14, 2026 at 2:38 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.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Speakers In Full
Ascend Acoustics CBM-170 SE2: $468 per pair Ascend Acoustics $468 eBay
Older model: the Ascend Acoustics CBM-170 SE (ranked lower, rated 2.1/5). See every Ascend CBM, HTM and CMT generation.
Same family: the Ascend Acoustics HTM-200SE2 (larger bookshelf, rated 4.3/5) and the Ascend Acoustics CMT-340 SE2 (larger bookshelf, ranked higher, rated 4.4/5).
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 6.30 unequalized (rising to 8.66 with an ideal subwoofer, or 6.79/8.86 with EQ applied): a strong result for a compact 2-way, and a clear step up from the original Ascend Acoustics 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 Acoustics CBM-170 SE2 review and specifications →
| Released | Jul 2026 (3 months ago) |
|---|---|
| Bass Extension (-10dB) | 50Hz (measured, manufacturer spinorama data) |
| Bass Extension (-3dB) | 70Hz (measured, manufacturer spinorama data) |
| DIY Kit | No |
| 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 | 6.30 |
| Spinorama Preference Score with Perfect Sub | 8.66 |
| Weight | 15 lbs (6.8 kg) each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Ascend Acoustics CBM-170 SE2 vs Polk Signature Elite ES20
- Ascend Acoustics CBM-170 SE2 vs Klipsch RP-600M II
- Ascend Acoustics CBM-170 SE2 vs Dynaudio Contour 20i
- Ascend Acoustics CBM-170 SE2 vs Dynaudio Emit 20
- Ascend Acoustics CBM-170 SE2 vs Philharmonic BMR Monitor
- Ascend Acoustics CBM-170 SE2 vs Mission LX-3 MKII
- Ascend Acoustics CBM-170 SE2 vs GR-Research X-LS Encore
- Ascend Acoustics CBM-170 SE2 vs Dynaudio Special Forty
- See all 48 comparisons
ATC SCM19: $3750 per pair The Music Room $3750 eBay
Same family: the ATC SCM40 (floorstanding, estimated 2.6/5).
Pros: Harmonic distortion at 96dB SPL/1m stays generally low across the range aside from the spike tied to the 700-800Hz resonance. Sealed (unported) cabinet avoids port noise and resonance, and the extremely dense, heavy-duty enclosure (17.8kg/39lb each) reflects ATC’s pro-audio build standards. Measured bass extension of 60Hz (-3dB), with a measured sensitivity of 85dB.
Cons: Some stored energy resonance around 500-700Hz, 4dB bump around 700Hz. Not recommended for the price. CEA2034 spinorama and predicted in-room response both show a very uneven overall balance (a broad accentuation from midrange to treble paired with too little bass) along with directivity error. At 96dB SPL/1m, harmonic distortion tied to the 500-700Hz resonance rises to a level the reviewer says “should not be there.”
Full ATC SCM19 review and specifications →
| Released | 2013 (13 years ago) |
|---|---|
| Bass Extension (-10dB) | 34Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 60Hz (measured, Audio Science Review) |
| DIY Kit | No |
| Dimensions | 17.2”H x 10.4”W x 11.8”D (436.9 x 264.2 x 299.7 mm) |
| Drivers | 5.9” Super Linear Magnet cone woofer, 1” soft dome tweeter |
| Impedance | 6 ohms |
| Sensitivity | 85dB (measured, Audio Science Review) |
| Spinorama Preference Score | 4.61 |
| Spinorama Preference Score with Perfect Sub | 7.03 |
| Weight | 39.2 lbs (17.8 kg) each |
| Woofer Cabinet | sealed |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons