Short answer: the AsciLab C6B. It ranks #6 of 216 bookshelf speakers by sound quality, rated 4.7/5, at $1,145. The Ascend Acoustics CMT-340 SE2 ranks #24, rated 4.4/5, at $798, $347 cheaper, which does not close the gap in sound quality.
The AsciLab C6B is the more accurate, deeper-bass pick. Two-way design pairing a 1” aluminum ceramic dome tweeter on a large waveguide with a 6” aluminum ceramic cone woofer, crossed over at 1.1kHz, plus a rear passive radiator. Its measured preference score, a predictor of how neutral it sounds, is 6.33 against 5.33 for the Ascend Acoustics CMT-340 SE2. Its bass reaches about 54Hz before falling 3dB, against 77.6Hz for the Ascend Acoustics CMT-340 SE2. The catch: Bass rolls off around 50Hz in-room (F3 54Hz, F10 35Hz), so a subwoofer is needed for real extension below that.
The case for the Ascend Acoustics CMT-340 SE2: High-quality manufacturer Klippel NFS data shows 0.295dB on-axis average absolute deviation, 0.531 listening-window smoothness, and a strong 7.99 preference score with a subwoofer. The catch: Bass rolls off early for the cabinet size, measuring 77.6Hz at -3dB, 64.5Hz at -6dB, and 48.3Hz at -12dB; the preference score without a subwoofer is only 5.33.
Buy the AsciLab C6B. It is rated higher for sound quality, and saving $347 with the Ascend Acoustics CMT-340 SE2 does not make up for the sound-quality gap.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| AsciLab C6B | Ascend Acoustics CMT-340 SE2 | |
|---|---|---|
| Price | $1145 per pair | $798 per pair |
| Ranked | #6 of 216 in Large Size Bookshelf Speakers | #24 of 216 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 35Hz (measured, Erin’s Audio Corner) | approximately 53Hz (measured, spinorama.org) |
| Bass Extension (-3dB) | 54Hz (measured, Erin’s Audio Corner) | 77.6Hz (measured, spinorama.org) |
| Dimensions | 15.7”H x 8”W x 10.4”D (398.8 x 203.2 x 264.2 mm) | 21 x 7.5 x 10.5 in each |
| Impedance | 4 ohms nominal, 2.6 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms nominal |
| Sensitivity | 85.6dB (measured, Erin’s Audio Corner) | 92dB at 2.83V/1m anechoic |
| Drivers | 6” Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1” Aluminium Ceramic Dome tweeter | Two 6.5-inch woofers; 27mm soft-dome tweeter |
| Weight | 18.5 lbs (8.4 kg) each | 29.1 lbs (13.2 kg) each |
| Woofer Cabinet | passive radiator | - |
| Spinorama Preference Score | 6.33 | 5.33 |
| Spinorama Preference Score with Perfect Sub | 8.28 | 7.99 |
| DIY Kit | No | No |
| Power Handling | - | 240W continuous; 400W short-term peak |
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: AsciLab C6B (measured by Erin’s Audio Corner) and Ascend Acoustics CMT-340 SE2 (measured by the manufacturer), via spinorama.org.
Related Speaker Comparisons
How AsciLab C6B compares with other leading options:
- AsciLab C6B vs Perlisten S4b
- AsciLab C6B vs KEF Reference 1 Meta
- AsciLab C6B vs GR-Research NX-Studio
- AsciLab C6B vs March Audio Sointuva AWG
- AsciLab C6B vs Audio First Cadentia 3
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The Two Speakers In Full
AsciLab C6B: $1145 per pair Ascilab $1145 eBay
Same family: the AsciLab C5B (smaller bookshelf, rated 4.2/5).
Pros: Two-way design pairing a 1” aluminum ceramic dome tweeter on a large waveguide with a 6” aluminum ceramic cone woofer, crossed over at 1.1kHz, plus a rear passive radiator. Unusual trait: horizontal radiation actually widens at higher frequencies instead of narrowing like most two-way designs, which keeps image focus and soundstage depth consistent whether you toe the speakers in or out (5-10° off-axis was the sweet spot in testing). Vertical radiation also stays wide straight through the 2kHz crossover region, so the sound doesn’t collapse when standing up: unusual at this price. CA2034 measurements show strong on-axis linearity, listening window, early reflections, and directivity. Midrange and tweeter distortion stay very low even at 96dB, holding up against a $5,900 Arendal speaker in that regard despite roughly a 5x price gap. At $1145 shipped to the US, the reviewer calls it the best-value bookshelf speaker he’s tested, rivaling speakers 2-5x the price. Measured bass extension of 54Hz (-3dB), with a measured sensitivity of 85.6dB.
Cons: Bass rolls off around 50Hz in-room (F3 54Hz, F10 35Hz), so a subwoofer is needed for real extension below that. Low-frequency harmonic distortion increases substantially at 96dB versus 86dB, though it’s second-order and less audible than it looks on paper. Minimum impedance dips to 2.6 ohms (EPDR as low as 1.2 ohms), so it wants an amplifier comfortable driving 4-ohm loads, ideally 100W or more. At 102dB, compression noticeably eats into midrange, bass, and some treble output. Shipping to the US adds roughly $200 on top of AsciLab’s list price. Against the reviewer’s reference Audiofirst Fidelia at a similar price, has slightly less lower-midrange body (about 1dB difference) and a smaller perceived soundstage size.
Full AsciLab C6B review and specifications →
| Bass Extension (-10dB) | 35Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 54Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 15.7”H x 8”W x 10.4”D (398.8 x 203.2 x 264.2 mm) |
| Drivers | 6” Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1” Aluminium Ceramic Dome tweeter |
| Impedance | 4 ohms nominal, 2.6 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | 85.6dB (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | 6.33 |
| Spinorama Preference Score with Perfect Sub | 8.28 |
| Weight | 18.5 lbs (8.4 kg) each |
| Woofer Cabinet | passive radiator |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Ascend Acoustics CMT-340 SE2: $798 per pair Ascend Acoustics $798 eBay
Older model: the Ascend Acoustics CMT-340 SE Center (rated 3.7/5). See every Ascend CBM, HTM and CMT generation.
Same family: the Ascend Acoustics CBM-170 SE2 (smaller bookshelf, ranked lower, rated 3.8/5) and the Ascend Acoustics HTM-200SE2 (smaller bookshelf, rated 4.3/5).
Pros: High-quality manufacturer Klippel NFS data shows 0.295dB on-axis average absolute deviation, 0.531 listening-window smoothness, and a strong 7.99 preference score with a subwoofer. Its dual 6.5-inch woofers, 92dB anechoic sensitivity, and 240W continuous power rating support high output and dynamics. Measured bass extension of 77.6Hz (-3dB).
Cons: Bass rolls off early for the cabinet size, measuring 77.6Hz at -3dB, 64.5Hz at -6dB, and 48.3Hz at -12dB; the preference score without a subwoofer is only 5.33. The 4.35 sound-power directivity-index standard deviation also indicates more off-axis variation than the strongest designs, and the rear port needs placement clearance.
Full Ascend Acoustics CMT-340 SE2 review and specifications →
| Released | Nov 2022 (3 years ago) |
|---|---|
| Bass Extension (-10dB) | approximately 53Hz (measured, spinorama.org) |
| Bass Extension (-3dB) | 77.6Hz (measured, spinorama.org) |
| DIY Kit | No |
| Dimensions | 21 x 7.5 x 10.5 in each |
| Drivers | Two 6.5-inch woofers; 27mm soft-dome tweeter |
| Impedance | 8 ohms nominal |
| Power Handling | 240W continuous; 400W short-term peak |
| Sensitivity | 92dB at 2.83V/1m anechoic |
| Spinorama Preference Score | 5.33 |
| Spinorama Preference Score with Perfect Sub | 7.99 |
| Weight | 29.1 lbs (13.2 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Ascend Acoustics CMT-340 SE2 vs Arendal 1528 Monitor 8
- Ascend Acoustics CMT-340 SE2 vs Wharfedale Super Linton
- Ascend Acoustics CMT-340 SE2 vs MoFi SourcePoint 10
- Ascend Acoustics CMT-340 SE2 vs AsciLab F6Bs
- Ascend Acoustics CMT-340 SE2 vs Radiant Acoustics Clarity 6.2
- Ascend Acoustics CMT-340 SE2 vs Dynaudio Heritage Special
- Ascend Acoustics CMT-340 SE2 vs MoFi SourcePoint 8
- Ascend Acoustics CMT-340 SE2 vs Buchardt Audio E50
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