Short answer: the Audio First Fidelia. It ranks #1 of 168 bookshelf speakers by sound quality (rated 4.8/5); the AsciLab C6B ranks #6 (rated 4.7/5).
What the Audio First Fidelia does well: Kit speaker offering exceptional value and tonal accuracy; chosen by reviewer as reference standard for future speaker tonality comparisons despite 1,250 USD price point. Watch for: Kit assembly required; lower sensitivity (~83-85 dB vs. typical 85 dB average) demands adequate amplifier power.
Why pick the AsciLab C6B: 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. The catch: Bass rolls off around 50Hz in-room (F3 54Hz, F10 35Hz), so a subwoofer is needed for real extension below that.
Buy the Audio First Fidelia. It is rated higher for sound quality than the AsciLab C6B.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| Audio First Fidelia | AsciLab C6B | |
|---|---|---|
| Price | £950 per pair for the flatpack kit (assembly required) | $1145 per pair |
| Ranked | #1 of 168 in Medium Size Bookshelf Speakers | #6 of 214 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 38Hz (measured, Erin’s Audio Corner) | 35Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | 53Hz (measured, Erin’s Audio Corner) | 54Hz (measured, Erin’s Audio Corner) |
| Crossover Frequency | 1560Hz | - |
| Dimensions | 11.8”H x 7.1”W x 11.7”D (300 x 180 x 297.6 mm) | 15.7”H x 8”W x 10.4”D (398.8 x 203.2 x 264.2 mm) |
| Impedance | 4 ohms | 4 ohms nominal, 2.6 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | 84dB | 85.6dB (measured, Erin’s Audio Corner) |
| Drivers | 5” ceramic-aluminum cone woofer, 1” ceramic-aluminum tweeter | 6” Aluminium Ceramic Cone with cast Aluminium Chassis woofer, 1” Aluminium Ceramic Dome tweeter |
| Weight | 15 lbs (6.8 kg) each | 18.5 lbs (8.4 kg) each |
| Woofer Cabinet | ported, rear | passive radiator |
| Spinorama Preference Score | 6.45 | 6.33 |
| Spinorama Preference Score with Perfect Sub | 8.46 | 8.28 |
| DIY Kit | Yes | No |
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.
Measurement data: Audio First Fidelia (measured by Erin’s Audio Corner) and AsciLab C6B (measured by Erin’s Audio Corner), via spinorama.org.
Watch Them Compared
Videos and reviews that test both speakers side by side.
- Erin’s Audio Corner: STOP Wasting Money on Bad Speakers – AsciLab C6B Review
- Erin’s Audio Corner: I Tested 250 Speakers So You Don’t Have To!
Related Speaker Comparisons
How Audio First Fidelia compares with other leading options:
- Philharmonic Ceramic Mini vs Audio First Fidelia
- Ascend Acoustics Sierra 1 v2 vs Audio First Fidelia
- KEF LS50 Meta vs Audio First Fidelia
- XMechanik Mechano23 DIY vs Audio First Fidelia
- Ascend Acoustics HTM-200SE2 vs Audio First Fidelia
Prices on this page were last checked October 10, 2026 at 5:37 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.
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The Two Speakers In Full
Audio First Fidelia: £950 per pair for the flatpack kit (assembly required) Audio First Designs eBay
Pros: Kit speaker offering exceptional value and tonal accuracy; chosen by reviewer as reference standard for future speaker tonality comparisons despite 1,250 USD price point. Achieves bass extension to 53 Hz (F3) and 38 Hz (F10) from compact cabinet. Direct-from-manufacturer availability eliminates retailer markup. Measured bass extension of 53Hz (-3dB).
Cons: Kit assembly required; lower sensitivity (~83-85 dB vs. typical 85 dB average) demands adequate amplifier power. Only available direct from UK manufacturer with associated shipping costs and lead times. Trade-off between compact driver configuration and maximum dynamic output.
Full Audio First Fidelia review and specifications →
| Bass Extension (-10dB) | 38Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 53Hz (measured, Erin’s Audio Corner) |
| Crossover Frequency | 1560Hz |
| DIY Kit | Yes |
| Dimensions | 11.8”H x 7.1”W x 11.7”D (300 x 180 x 297.6 mm) |
| Drivers | 5” ceramic-aluminum cone woofer, 1” ceramic-aluminum tweeter |
| Impedance | 4 ohms |
| Sensitivity | 84dB |
| Spinorama Preference Score | 6.45 |
| Spinorama Preference Score with Perfect Sub | 8.46 |
| Weight | 15 lbs (6.8 kg) each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: The #1 Reason audiophiles Are Raving About Fidelia’s Sound Quality More from Erin’s Audio Corner →
- Erin’s Audio Corner: I Tested 250 Speakers So You Don’t Have To!
- Erin’s Audio Corner: My Absolute Favorite Products of 2024 Revealed
- Erin’s Audio Corner Measurements (spinorama.org)
- Erin’s Audio Corner Website: Audio First Fidelia
- Erin’s Audio Corner: STOP Wasting Money on Bad Speakers – AsciLab C6B Review
- Head-to-Head Comparisons
- Audio First Fidelia vs Philharmonic Ceramic Mini
- Audio First Fidelia vs Ascend Acoustics Sierra 1 v2
- Audio First Fidelia vs KEF LS50 Meta
- Audio First Fidelia vs XMechanik Mechano23 DIY
- Audio First Fidelia vs Ascend Acoustics HTM-200SE2
- Audio First Fidelia vs Arendal 1961 Monitor
- Audio First Fidelia vs Ascend Acoustics Luna V2 Mini-Monitor Titan
- Audio First Fidelia vs Aalto Speakers Aalto 1 EVO
- See all 27 comparisons
AsciLab C6B: $1145 per pair Ascilab 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