Short answer: the KEF R3. It ranks #15 of 222 bookshelf speakers by sound quality (rated 4.5/5) at $1,544.56 and is still sold new; the Monolith Encore B6 ranks #99 (rated 3.9/5) and is discontinued, so it is only an option used.
The KEF R3 is the more accurate, deeper-bass choice. 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. Its measured preference score, a predictor of how neutral it sounds, is 6.20 against 4.67 for the Monolith Encore B6. Its bass reaches about 58Hz before falling 3dB, against 68Hz for the Monolith Encore B6. The tradeoff: 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.
Why pick the Monolith Encore B6: Budget bookshelf speakers with punchy midbass, smooth wide dispersion and an unusually solid braced cabinet for the price. The catch: Erin measured 85.3dB sensitivity and a 3.4-ohm minimum, so this is not an easy load despite its modest output ceiling.
Buy the KEF R3. It is rated higher for sound quality, and the Monolith Encore B6 is discontinued, so it is only available used.
Looking for alternatives? See the complete Passive Home rankings.
Measured Differences
- Close enough not to matter: bass extension (35.2 Hz vs 37 Hz, 10 dB down).
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Specifications Side By Side
| KEF R3 | Monolith Encore B6 | |
|---|---|---|
| Price | $1,544.56 per pair | $360 per pair Discontinued |
| Ranked | #15 of 222 in Large Size Bookshelf Speakers | #99 of 222 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | Approximately 58Hz (manufacturer specified; consistent with Erin’s measured roll-off) | 68Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | 35.2Hz (measured, Audio Science Review) | 37Hz (measured, Erin’s Audio Corner) |
| Sensitivity | Approximately 86-87dB/2.83V/1m (measured, Erin’s Audio Corner) | 85.3dB/2.83V/1m (measured, Erin’s Audio Corner) |
| Impedance | 8 ohms nominal; suitable for Erin’s 4/8-ohm-rated amplifier | 4 ohms nominal; 3.4 ohms minimum (measured, Erin’s Audio Corner) |
| Drivers | 1” tweeter coaxial with 5” midrange; 6.5” woofer | 6.5-inch pulp woofer; 25mm waveguided silk dome |
| Dimensions | 16.6”H x 7.9”W x 13.2”D | 15.7H x 7.9W x 9.9D inches |
| Woofer Cabinet | ported, rear Flexible Port | - |
| Weight | 29.9 lbs (13.55 kg) each | 15.4 lbs (7.0 kg) each |
| Spinorama Preference Score | 6.2 (spinorama.org) | 4.67 |
| Spinorama Preference Score with Perfect Sub | 7.97 (spinorama.org) | 6.93 |
| DIY Kit | No | No |
Where the Ratings Come From
- KEF R3: Spinorama.org measurements and reviews by Erin’s Audio Corner and Audio Science Review.
- Monolith Encore B6: Spinorama.org measurements and reviews by Erin’s Audio Corner video.
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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