Short answer: the Radiant Acoustics Clarity 66 if sound quality matters most, the Q Acoustics 5040 if price matters most. The Radiant Acoustics Clarity 66 ranks #5 of 71 floorstanding speakers at $7998. The Q Acoustics 5040 ranks #33 at $1236.49, $6761.51 cheaper.
What the Radiant Acoustics Clarity 66 offers: ASR’s revised Spinorama measurement shows bass reaching 32.2Hz at -3dB and 27.8Hz at -6dB, giving substantial low-end weight without a subwoofer. The response spans 2.3dB from 300Hz to 5kHz, with preference scores of 5.10 standalone and 6.12 with an ideal subwoofer. The review’s exceptionally low bass distortion at ordinary levels complements that extension, while dual 6.5-inch Purifi woofers provide a strong foundation for full-range listening. Watch for: Vertical directivity is narrow and horizontal coverage is uneven, so listening height and placement affect tonal balance. Treble resonances and response irregularities keep it from reference-level neutrality. Spinorama’s modeled EQ improves the scores to 6.09 standalone and 6.99 with an ideal subwoofer, but those are corrected results, not stock performance. Measured sensitivity is 85.9dB at 2.83V/1m with a nominal 4-ohm load; use an amplifier comfortable driving 4 ohms. Distortion rises at very high playback levels.
What the Q Acoustics 5040 offers: C3 (Continuous Curved Cone) driver profile technology provides smooth midrange integration, controlled cone breakup, and improved bass damping. High voltage sensitivity (91.5dB SPL at 2.83V/1m) allows loud listening with low-to-moderate amplifier wattage. Cabinet features Point-to-Point (P2P) internal bracing and Helmholtz Pressure Equalizer (HPE) tubes to suppress internal standing waves and panel vibrations. Watch for: Free-field frequency response exhibits a noticeable mid-bass scoop around 200Hz (~6dB lower than mean SPL), causing an F3 of 70Hz (F10 of 39Hz) in open space and requiring boundary placement (11-22 inches from front wall) to reinforce upper bass output. Measurements indicate an enclosure resonance near 300Hz visible in sound power data. Minimum impedance drops to 3.0 ohms, demanding a stable 4-ohm rated amplifier despite high sensitivity.
Buy the Radiant Acoustics Clarity 66 if sound quality is the priority over the price, or the Q Acoustics 5040 if the price is the priority over sound quality.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| Radiant Acoustics Clarity 66 | Q Acoustics 5040 | |
|---|---|---|
| Price | $7,998 per pair | $1,236.49 per pair |
| Ranked | #5 of 71 in Large Size Floorstanding Speakers | #33 of 71 in Large Size Floorstanding Speakers |
| Bass Extension (-3dB) | 32.2Hz (measured, Audio Science Review) | 70Hz (measured, Erin's Audio Corner) |
| Bass Extension (-10dB) | 24.4Hz (measured, Audio Science Review) | 39Hz (measured, Erin's Audio Corner) |
| Sensitivity | 85.9dB (2.83V/1m, measured, Audio Science Review; 86dB manufacturer specified) | 91.5dB (measured average, Erin's Audio Corner) |
| Drivers | Custom waveguide-loaded tweeter with beam-expansion fins, 2x 6.5" Purifi USHINDI aluminum-cone woofers | 0.88 in. decoupled dome tweeter, twin 5.0 in. C3 Continuous Curved Cone woofers |
| Dimensions | 40.4"H x 8.7"W x 14"D (1025 x 222 x 355 mm) | 38.1"H x 11.5"W x 14.2"D (967 x 293 x 361 mm) |
| Weight | 101.4 lbs (46 kg) each | 39.7 lbs (18.0 kg) each |
| Impedance | 4 ohms nominal | 6 ohms nominal (3.0 ohms minimum, measured by Erin's Audio Corner) |
| Crossover Frequency | 2.4kHz | - |
| Woofer Cabinet | ported, large rear port | ported, rear |
| Spinorama Preference Score | 5.10 | 2.90 |
| Spinorama Preference Score with Perfect Sub | 6.12 | 5.52 |
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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.
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The Two Speakers In Full
Radiant Acoustics Clarity 66: $7,998 per pair Radiant Acoustics eBay
Pros: ASR’s revised Spinorama measurement shows bass reaching 32.2Hz at -3dB and 27.8Hz at -6dB, giving substantial low-end weight without a subwoofer. The response spans 2.3dB from 300Hz to 5kHz, with preference scores of 5.10 standalone and 6.12 with an ideal subwoofer. The review’s exceptionally low bass distortion at ordinary levels complements that extension, while dual 6.5-inch Purifi woofers provide a strong foundation for full-range listening. Measured bass extension of 32.2Hz (-3dB), with a measured sensitivity of 85.9dB.
Cons: Vertical directivity is narrow and horizontal coverage is uneven, so listening height and placement affect tonal balance. Treble resonances and response irregularities keep it from reference-level neutrality. Spinorama’s modeled EQ improves the scores to 6.09 standalone and 6.99 with an ideal subwoofer, but those are corrected results, not stock performance. Measured sensitivity is 85.9dB at 2.83V/1m with a nominal 4-ohm load; use an amplifier comfortable driving 4 ohms. Distortion rises at very high playback levels.
Full Radiant Acoustics Clarity 66 review and specifications →
| Bass Extension (-10dB) | 24.4Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 32.2Hz (measured, Audio Science Review) |
| Crossover Frequency | 2.4kHz |
| Dimensions | 40.4"H x 8.7"W x 14"D (1025 x 222 x 355 mm) |
| Drivers | Custom waveguide-loaded tweeter with beam-expansion fins, 2x 6.5" Purifi USHINDI aluminum-cone woofers |
| Impedance | 4 ohms nominal |
| Sensitivity | 85.9dB (2.83V/1m, measured, Audio Science Review; 86dB manufacturer specified) |
| Spinorama Preference Score | 5.10 |
| Spinorama Preference Score with Perfect Sub | 6.12 |
| Weight | 101.4 lbs (46 kg) each |
| Woofer Cabinet | ported, large rear port |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Radiant Acoustics Clarity 66 vs Ascend Acoustics ELX Ribbon Tower
- Radiant Acoustics Clarity 66 vs MoFi SourcePoint 888
- Radiant Acoustics Clarity 66 vs MoFi SourcePoint V10 Master Edition
- Radiant Acoustics Clarity 66 vs KEF Blade Two Meta
- Radiant Acoustics Clarity 66 vs Revel F328Be
- Radiant Acoustics Clarity 66 vs Revel F226Be
- Radiant Acoustics Clarity 66 vs JBL 4367
- Radiant Acoustics Clarity 66 vs Revel F228Be
- See all 23 comparisons
Q Acoustics 5040: $1,236.49 per pair Amazon eBay
Pros: C3 (Continuous Curved Cone) driver profile technology provides smooth midrange integration, controlled cone breakup, and improved bass damping. High voltage sensitivity (91.5dB SPL at 2.83V/1m) allows loud listening with low-to-moderate amplifier wattage. Cabinet features Point-to-Point (P2P) internal bracing and Helmholtz Pressure Equalizer (HPE) tubes to suppress internal standing waves and panel vibrations. Measured bass extension of 70Hz (-3dB), with a measured sensitivity of 91.5dB.
Cons: Free-field frequency response exhibits a noticeable mid-bass scoop around 200Hz (~6dB lower than mean SPL), causing an F3 of 70Hz (F10 of 39Hz) in open space and requiring boundary placement (11-22 inches from front wall) to reinforce upper bass output. Measurements indicate an enclosure resonance near 300Hz visible in sound power data. Minimum impedance drops to 3.0 ohms, demanding a stable 4-ohm rated amplifier despite high sensitivity.
Full Q Acoustics 5040 review and specifications →
| Bass Extension (-10dB) | 39Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 70Hz (measured, Erin's Audio Corner) |
| Dimensions | 38.1"H x 11.5"W x 14.2"D (967 x 293 x 361 mm) |
| Drivers | 0.88 in. decoupled dome tweeter, twin 5.0 in. C3 Continuous Curved Cone woofers |
| Impedance | 6 ohms nominal (3.0 ohms minimum, measured by Erin's Audio Corner) |
| Sensitivity | 91.5dB (measured average, Erin's Audio Corner) |
| Spinorama Preference Score | 2.90 |
| Spinorama Preference Score with Perfect Sub | 5.52 |
| Weight | 39.7 lbs (18.0 kg) each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Q Acoustics 5040 vs Polk Audio Reserve R700
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- Q Acoustics 5040 vs Polk Reserve R500
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