Short answer: the AsciLab C6B. It ranks #7 of 130 bookshelf speakers by sound quality at $1145; the ATC SCM19 ranks #119 and costs $3750, which makes this an easy call rather than a real tradeoff.
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 ATC SCM19 offers: 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. Watch for: 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.”
Buy the AsciLab C6B. It ranks higher for sound quality than the ATC SCM19 and costs less, which settles it without a real tradeoff to make.
If sound quality matters at all to you, skip the ATC SCM19. It ranks near the bottom of the 130 bookshelf speakers, so look higher up the list instead.
Want more options? Browse the full Passive Home rankings.
Specifications Side By Side
| AsciLab C6B | ATC SCM19 | |
|---|---|---|
| Price | $1145 per pair | $3750 per pair |
| Ranked | #7 of 130 in Large Size Bookshelf Speakers | #119 of 130 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 35Hz (measured, Erin's Audio Corner) | 34Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 54Hz (measured, Erin's Audio Corner) | 60Hz (measured, Audio Science Review) |
| Dimensions | 15.7"H x 8"W x 10.4"D (398.8 x 203.2 x 264.2 mm) | 17.2"H x 10.4"W x 11.8"D (436.9 x 264.2 x 299.7 mm) |
| Impedance | 4 ohms nominal, 2.6 ohms minimum (measured, Erin's Audio Corner) | 6 ohms |
| Sensitivity | 85.6dB (measured, Erin's Audio Corner) | 85dB (measured, Audio Science Review) |
| Drivers | 6" Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1" Aluminium Ceramic Dome tweeter | 5.9" Super Linear Magnet cone woofer, 1" soft dome tweeter |
| Weight | 18.5 lbs (8.4 kg) each | 39.2 lbs (17.8 kg) each |
| Woofer Cabinet | passive radiator | sealed |
| Spinorama Preference Score | 5.66 | 3.79 |
| Spinorama Preference Score with Perfect Sub | 7.60 | 6.21 |
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
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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
ATC SCM19: $3750 per pair Tmraudio eBay
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 →
| Bass Extension (-10dB) | 34Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 60Hz (measured, Audio Science Review) |
| 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 | 3.79 |
| Spinorama Preference Score with Perfect Sub | 6.21 |
| Weight | 39.2 lbs (17.8 kg) each |
| Woofer Cabinet | sealed |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons