Short answer: the AsciLab C6B on measured sound quality, the Polk Signature Elite ES20 on price. The AsciLab C6B ranks #7 of 130 bookshelf speakers at $1145. The Polk Signature Elite ES20 ranks #69 at $359, $786 cheaper.
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 Polk Signature Elite ES20 offers: A full-size, efficient 6.5-inch bookshelf pair with unusually deep bass for the price. ASR measured 41Hz estimated in-room extension, a well-damped Q of 0.66, broad horizontal coverage to roughly +/-60 degrees and a 5.54 preference score with a subwoofer. Watch for: Predicted in-room smoothness of 0.238 and directivity-index consistency of 3.81 are average rather than class-leading. The deep cabinet needs substantial shelf or stand space, and its Power Port still requires rear clearance.
Buy the AsciLab C6B if sound quality matters more than the price. Buy the Polk Signature Elite ES20 if the price matters more than sound quality.
Looking for alternatives? See the complete Passive Home rankings.
Specifications Side By Side
| AsciLab C6B | Polk Signature Elite ES20 | |
|---|---|---|
| Price | $1145 per pair | $359 per pair |
| Ranked | #7 of 130 in Large Size Bookshelf Speakers | #69 of 130 in Large Size Bookshelf Speakers |
| 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) | 14.8H x 8.5W x 13.8D in |
| Impedance | 4 ohms nominal, 2.6 ohms minimum (measured, Erin's Audio Corner) | 4/8-ohm compatible |
| Sensitivity | 85.6dB (measured, Erin's Audio Corner) | 86dB |
| Drivers | 6" Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1" Aluminium Ceramic Dome tweeter | 1" Terylene dome tweeter, 6.5" polypropylene woofer |
| Weight | 18.5 lbs (8.4 kg) each | 17 lbs (7.7 kg) each |
| Woofer Cabinet | passive radiator | - |
| Spinorama Preference Score | 5.66 | 3.60 |
| Spinorama Preference Score with Perfect Sub | 7.60 | 5.54 |
| Enclosure | - | 2-way, Power Port bass-reflex |
| Country | - | United States (design) |
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
Prices on this page were last checked September 16, 2026 at 12:41 AM 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 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
Polk Signature Elite ES20: $359 per pair B&H Photo Video eBay
Pros: A full-size, efficient 6.5-inch bookshelf pair with unusually deep bass for the price. ASR measured 41Hz estimated in-room extension, a well-damped Q of 0.66, broad horizontal coverage to roughly +/-60 degrees and a 5.54 preference score with a subwoofer.
Cons: Predicted in-room smoothness of 0.238 and directivity-index consistency of 3.81 are average rather than class-leading. The deep cabinet needs substantial shelf or stand space, and its Power Port still requires rear clearance.
Full Polk Signature Elite ES20 review and specifications →
| Country | United States (design) |
|---|---|
| Dimensions | 14.8H x 8.5W x 13.8D in |
| Drivers | 1" Terylene dome tweeter, 6.5" polypropylene woofer |
| Enclosure | 2-way, Power Port bass-reflex |
| Impedance | 4/8-ohm compatible |
| Sensitivity | 86dB |
| Spinorama Preference Score | 3.60 |
| Spinorama Preference Score with Perfect Sub | 5.54 |
| Weight | 17 lbs (7.7 kg) each |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Polk Signature Elite ES20 vs Ascend CBM-170 SE2
- Polk Signature Elite ES20 vs Klipsch RP-600M II
- Polk Signature Elite ES20 vs Dynaudio Emit 20
- Polk Signature Elite ES20 vs Philharmonic BMR Monitor
- Polk Signature Elite ES20 vs Dynaudio Contour 20i
- Polk Signature Elite ES20 vs Mission LX-3 MKII
- Polk Signature Elite ES20 vs ELAC DBR62
- Polk Signature Elite ES20 vs GR-Research X-LS Encore
- See all 44 comparisons