Short answer: the March Audio Sointuva AWG on measured sound quality, the KEF R3 on price. The March Audio Sointuva AWG ranks #5 of 222 bookshelf speakers, rated 4.7/5, at $4,150. The KEF R3 ranks #15, rated 4.5/5, at $1,544.56, $2,605.44 cheaper.
The March Audio Sointuva AWG is the more accurate, deeper-bass option. A Purifi powered bookshelf speaker with extremely flat sound, very low distortion, and unusually deep bass for its size. Its measured preference score, a predictor of how neutral it sounds, is 6.95 against 6.20 for the KEF R3. Its bass reaches about 40Hz before falling 3dB, against 58Hz for the KEF R3. The tradeoff: Correct listening axis sits about 7° above the tweeter line, which means shorter stands (around 24”) than typical bookshelf stands are sold at: get the height wrong and the sound scoops out in the mid/high frequencies.
The case for the KEF R3: A three way bookshelf speaker with KEF’s coaxial driver for stable imaging across seats and very low distortion, easy to run with a modest amp. The catch: The low-frequency alignment rolls gradually rather than delivering high-output sub-bass; KEF specifies 58Hz +/-3dB and Erin’s high-level data supports using an 80Hz subwoofer crossover.
Buy the March Audio Sointuva AWG when sound quality outweighs the price for you, and the KEF R3 when the price outweighs sound quality instead.
Still deciding? The full Passive Home rankings cover every ranked option.
Measured Differences
- Bass depth: the March Audio Sointuva AWG reaches 30 Hz (10 dB down) against 35.2 Hz for the KEF R3, about half an octave deeper. You hear more of the lowest bass notes and kick drums.
- Efficiency: the KEF R3 is rated at 86 dB sensitivity against 82.4 dB for the March Audio Sointuva AWG, so it plays as loud with roughly half the amplifier power.
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Specifications Side By Side
| March Audio Sointuva AWG | KEF R3 | |
|---|---|---|
| Price | $4150 per pair | $1,544.56 per pair |
| Ranked | #5 of 222 in Large Size Bookshelf Speakers | #15 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-10dB) | 30Hz (measured, Erin’s Audio Corner) | 35.2Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 40Hz (measured, Erin’s Audio Corner) | Approximately 58Hz (manufacturer specified; consistent with Erin’s measured roll-off) |
| Dimensions | 17.7”H x 9.4”W x 8.7”D (449.6 x 238.8 x 221 mm) | 16.6”H x 7.9”W x 13.2”D |
| Impedance | 6 ohms | 8 ohms nominal; suitable for Erin’s 4/8-ohm-rated amplifier |
| Sensitivity | 82.4dB (measured, Erin’s Audio Corner) | Approximately 86-87dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Drivers | 6.5” Purifi PTT-OEM Midwoofer, Satori TW29BNWG-4 Beryllium Dome Tweeter with Waveguide | 1” tweeter coaxial with 5” midrange; 6.5” woofer |
| Woofer Cabinet | passive radiator | ported, rear Flexible Port |
| Weight | 11 lbs (5 kg) | 29.9 lbs (13.55 kg) each |
| Spinorama Preference Score | 6.95 | 6.2 (spinorama.org) |
| Spinorama Preference Score with Perfect Sub | 8.45 | 7.97 (spinorama.org) |
| DIY Kit | No | No |
Where the Ratings Come From
- March Audio Sointuva AWG: Spinorama.org measurements and reviews by Erin’s Audio Corner.
- KEF R3: Spinorama.org measurements and reviews by Erin’s Audio Corner and Audio Science Review.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
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