Short answer: the AsciLab C6B. It ranks #7 of 130 bookshelf speakers by sound quality at $1145; the Buchardt Audio E50 ranks #16 and costs $4600, so there is little reason to consider the other one.
What the AsciLab C6B offers: 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 $935 (about $1,135 shipped to the US), the reviewer calls it the best-value bookshelf speaker he’s tested, rivaling speakers 2-5x the price. Watch for: 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 the $935 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.
What the Buchardt Audio E50 offers: Exceptional bass extension for a bookshelf - F3 at 40Hz, F10 at 34Hz - with genuinely low-end weight the reviewer kept noticing track after track, not just a single room-boosted note. Mid and lower-midrange are very neutral with no coloration and well-executed baffle-step compensation, so it doesn’t need to sit close to a wall like many bookshelf designs. Low distortion throughout the midrange, controlled ~60-degree horizontal directivity, and a striking driver/waveguide integration that looks genuinely upscale. Watch for: A roughly 3dB dip in the upper midrange/lower treble softens attack and dialogue clarity - the reviewer’s main complaint, and it’s baked into the crossover rather than a directivity artifact, so it’s audible both on and off axis. Sounds too bright pointed directly at the listener; needs about 10-20 degrees of toe-out to tame the treble and slightly smooth (not eliminate) that dip. Below-average sensitivity (measured 83.1dB vs 85dB spec) calls for a beefier amp, and the speaker’s tonal balance is unusually sensitive to amplifier output impedance - a poor tube amp can shift the midrange by up to 2dB.
Buy the AsciLab C6B. It ranks higher for sound quality than the Buchardt Audio E50 and costs less, so there is no real case for the other one.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| AsciLab C6B | Buchardt Audio E50 | |
|---|---|---|
| Price | $1145 per pair | $4600 per pair |
| Ranked | #7 of 130 in Large Size Bookshelf Speakers | #16 of 130 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 35Hz (measured, Erin's Audio Corner) | 34Hz (measured, Erin's Audio Corner) |
| Bass Extension (-3dB) | 54Hz (measured, Erin's Audio Corner) | 40Hz (measured, Erin's Audio Corner) |
| Dimensions | 15.7"H x 8"W x 10.4"D (398.8 x 203.2 x 264.2 mm) | 15.6" x 7.5" x 11.2" (395 x 190 x 284 mm) |
| Impedance | 4 ohms nominal, 2.6 ohms minimum (measured, Erin's Audio Corner) | 4 ohms nominal |
| Sensitivity | 85.6dB (measured, Erin's Audio Corner) | 83.1dB (2.83V/1m, measured by Erin's Audio Corner) |
| Drivers | 6" Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1" Aluminium Ceramic Dome tweeter | 1" Scanspeak dome tweeter with waveguide, 6.5" Purifi extended-stroke woofer, dual 6.5" passive radiators |
| Weight | 18.5 lbs (8.4 kg) each | 19 lbs (8.6 kg) each |
| Woofer Cabinet | passive radiator | Passive radiator loaded |
| Spinorama Preference Score | 5.66 | 5.03 |
| Spinorama Preference Score with Perfect Sub | 7.60 | 6.80 |
| Crossover Frequency | - | 2000Hz |
| Frequency Response | - | 36Hz - 30kHz ±3dB (Manufacturer specified) |
| Recommended Power | - | 60W - 200W |
| Country | - | Denmark |
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 eBay
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 $935 (about $1,135 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 the $935 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) |
| 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 | 5.66 |
| Spinorama Preference Score with Perfect Sub | 7.60 |
| Weight | 18.5 lbs (8.4 kg) each |
| Woofer Cabinet | passive radiator |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Buchardt Audio E50: $4600 per pair Buchardt Audio eBay
Pros: Exceptional bass extension for a bookshelf - F3 at 40Hz, F10 at 34Hz - with genuinely low-end weight the reviewer kept noticing track after track, not just a single room-boosted note. Mid and lower-midrange are very neutral with no coloration and well-executed baffle-step compensation, so it doesn’t need to sit close to a wall like many bookshelf designs. Low distortion throughout the midrange, controlled ~60-degree horizontal directivity, and a striking driver/waveguide integration that looks genuinely upscale. Measured bass extension of 40Hz (-3dB), with a measured sensitivity of 83.1dB.
Cons: A roughly 3dB dip in the upper midrange/lower treble softens attack and dialogue clarity - the reviewer’s main complaint, and it’s baked into the crossover rather than a directivity artifact, so it’s audible both on and off axis. Sounds too bright pointed directly at the listener; needs about 10-20 degrees of toe-out to tame the treble and slightly smooth (not eliminate) that dip. Below-average sensitivity (measured 83.1dB vs 85dB spec) calls for a beefier amp, and the speaker’s tonal balance is unusually sensitive to amplifier output impedance - a poor tube amp can shift the midrange by up to 2dB.
Full Buchardt Audio E50 review and specifications →
| Bass Extension (-10dB) | 34Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 40Hz (measured, Erin's Audio Corner) |
| Country | Denmark |
| Crossover Frequency | 2000Hz |
| Dimensions | 15.6" x 7.5" x 11.2" (395 x 190 x 284 mm) |
| Drivers | 1" Scanspeak dome tweeter with waveguide, 6.5" Purifi extended-stroke woofer, dual 6.5" passive radiators |
| Frequency Response | 36Hz - 30kHz ±3dB (Manufacturer specified) |
| Impedance | 4 ohms nominal |
| Recommended Power | 60W - 200W |
| Sensitivity | 83.1dB (2.83V/1m, measured by Erin's Audio Corner) |
| Spinorama Preference Score | 5.03 |
| Spinorama Preference Score with Perfect Sub | 6.80 |
| Weight | 19 lbs (8.6 kg) each |
| Woofer Cabinet | Passive radiator loaded |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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- Buchardt Audio E50 vs KEF Q Concerto Meta
- Buchardt Audio E50 vs Arendal 1528 Monitor 8
- Buchardt Audio E50 vs KEF R3 Meta
- Buchardt Audio E50 vs Ascend Acoustics CMT-340 SE2
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