Short answer: the AsciLab C6B. It ranks #6 of 216 bookshelf speakers by sound quality (rated 4.7/5); the Mission LX-3 MKII ranks #134 (rated 3.6/5).
The AsciLab C6B is the more accurate, deeper-bass choice. 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 4.17 for the Mission LX-3 MKII. Its bass reaches about 54Hz before falling 3dB, against 67.4Hz for the Mission LX-3 MKII. The catch: Bass rolls off around 50Hz in-room (F3 54Hz, F10 35Hz), so a subwoofer is needed for real extension below that.
What the Mission LX-3 MKII does well: A large affordable standmount with a 6.5-inch woofer, 88dB rated sensitivity and useful bass. The catch: On-axis smoothness of 0.217 and predicted in-room smoothness of 0.344 reveal clear response unevenness, with a -0.46dB-per-octave downward tilt.
Buy the AsciLab C6B. It is rated higher for sound quality than the Mission LX-3 MKII.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| AsciLab C6B | Mission LX-3 MKII | |
|---|---|---|
| Price | $1145 per pair | £249 per pair |
| Ranked | #6 of 216 in Large Size Bookshelf Speakers | #134 of 216 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 35Hz (measured, Erin’s Audio Corner) | 42.5Hz (derived from ASR on-axis curve, spinorama.org) |
| Bass Extension (-3dB) | 54Hz (measured, Erin’s Audio Corner) | 67.4Hz (measured, ASR via spinorama.org) |
| Dimensions | 15.7”H x 8”W x 10.4”D (398.8 x 203.2 x 264.2 mm) | 13.6H x 8.9W x 12.1D in |
| Impedance | 4 ohms nominal, 2.6 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms nominal, 4.1 ohms minimum |
| Sensitivity | 85.6dB (measured, Erin’s Audio Corner) | 88dB |
| Drivers | 6” Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1” Aluminium Ceramic Dome tweeter | 1” microfiber-dome tweeter, 6.5” composite-fiber woofer |
| Weight | 18.5 lbs (8.4 kg) each | 18.5 lbs (8.4 kg) each |
| Woofer Cabinet | passive radiator | - |
| Spinorama Preference Score | 6.33 | 4.17 |
| Spinorama Preference Score with Perfect Sub | 8.28 | 6.42 |
| DIY Kit | No | No |
| Enclosure | - | 2-way, bass-reflex |
| Country | - | United Kingdom (design) |
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 Mission LX-3 MKII (measured by Audio Science Review), via spinorama.org.
Related Speaker Comparisons
More worthwhile head-to-heads for AsciLab C6B:
- 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
Prices on this page were last checked October 12, 2026 at 4:13 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
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
Mission LX-3 MKII: £249 per pair Richer Sounds eBay
Pros: A large affordable standmount with a 6.5-inch woofer, 88dB rated sensitivity and useful bass. ASR measured 48Hz estimated in-room extension, a controlled Q of 0.60, a 6.42 subwoofer-assisted preference score and reasonable +/-55-degree horizontal coverage. Measured bass extension of 67.4Hz (-3dB).
Cons: On-axis smoothness of 0.217 and predicted in-room smoothness of 0.344 reveal clear response unevenness, with a -0.46dB-per-octave downward tilt. The 345mm-tall, 8.4kg cabinet is bulky and current US availability is limited.
Full Mission LX-3 MKII review and specifications →
| Released | Jan 2021 (5 years ago) |
|---|---|
| Bass Extension (-10dB) | 42.5Hz (derived from ASR on-axis curve, spinorama.org) |
| Bass Extension (-3dB) | 67.4Hz (measured, ASR via spinorama.org) |
| Country | United Kingdom (design) |
| DIY Kit | No |
| Dimensions | 13.6H x 8.9W x 12.1D in |
| Drivers | 1” microfiber-dome tweeter, 6.5” composite-fiber woofer |
| Enclosure | 2-way, bass-reflex |
| Impedance | 8 ohms nominal, 4.1 ohms minimum |
| Sensitivity | 88dB |
| Spinorama Preference Score | 4.17 |
| Spinorama Preference Score with Perfect Sub | 6.42 |
| Weight | 18.5 lbs (8.4 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Mission LX-3 MKII vs Philharmonic BMR Monitor
- Mission LX-3 MKII vs Dynaudio Emit 20
- Mission LX-3 MKII vs GR-Research X-LS Encore
- Mission LX-3 MKII vs Dynaudio Special Forty
- Mission LX-3 MKII vs ELAC Debut 2.0 B6.2
- Mission LX-3 MKII vs SVS Prime Bookshelf
- Mission LX-3 MKII vs Klipsch RP-600M II
- Mission LX-3 MKII vs KEF Q3 Meta
- See all 44 comparisons