Short answer: the KEF R3 Meta is the proven choice, measured and ranked among bookshelf speakers, while the newer Buchardt S400 MK3 has no independent measurements yet and can only be compared on specs.
The case for the Buchardt S400 MK3: A ground-up redesign of the S400 with an 18 percent larger cabinet and a 7.5” SB Acoustics Satori Papyrus paper cone woofer, which Buchardt says has 65.5 percent more displacement than the MKII’s 6” driver.
On the KEF R3 Meta side: Three-way design with an unconventional concentric layout: the 1” tweeter is recessed into the throat of the 5.25” midrange driver, deeper integration than a standard coaxial arrangement.
Price: the Buchardt S400 MK3 lists at $2,300 and the KEF R3 Meta at $2,499.99.
Buy the KEF R3 Meta if you want a speaker whose sound quality has been measured and ranked.
Buy the Buchardt S400 MK3 if you prefer its design or features, and you can wait for measurements to confirm how it sounds.
Still deciding? The full Passive Home rankings cover every ranked option.
Specifications Side By Side
| Buchardt S400 MK3 | KEF R3 Meta | |
|---|---|---|
| Price | $2,300 per pair | $2,499.99 per pair |
| Ranked | - | #10 of 131 in Large Size Bookshelf Speakers |
| Crossover Frequency | 2.2kHz (first order) | - |
| Dimensions | 392H x 198W x 280D mm | 16.6”H x 7.9”W x 13.2”D (421.6 x 200.7 x 335.3 mm) |
| DIY Kit | No | No |
| Drivers | 1” aluminum dome tweeter in waveguide, 7.5” Satori Papyrus paper cone woofer | 6.5” Hybrid aluminum ported woofer, 5” aluminum cone midrange, 1” vented aluminium dome with MAT tweeter |
| Frequency Response | 33Hz - 20kHz (in-room, manufacturer specified) | - |
| Impedance | 4 ohms | 4 ohms nominal (3.2 ohms minimum above 80Hz, measured, Erin’s Audio Corner) |
| Sensitivity | 87dB anechoic, 90dB in-room (manufacturer specified) | 85.9dB (measured, Erin’s Audio Corner; 87dB manufacturer specified) |
| Weight | 8.5 kg each | 27.3 lbs (12.4 kg) each |
| Woofer Cabinet | ported, rear | ported |
| Bass Extension (-10dB) | - | 37Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | - | 76Hz (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | - | 6.10 |
| Spinorama Preference Score with Perfect Sub | - | 7.91 |
Prices on this page were last checked September 29, 2026 at 3:43 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
Buchardt S400 MK3: $2,300 per pair Buchardt Audio eBay
Older models: the Buchardt Audio S400 (rated 4.4/5) and the Buchardt S400 MKII (rated 3.8/5).
Pros: A ground-up redesign of the S400 with an 18 percent larger cabinet and a 7.5” SB Acoustics Satori Papyrus paper cone woofer, which Buchardt says has 65.5 percent more displacement than the MKII’s 6” driver. A custom 1” aluminum dome tweeter sits in a new waveguide, crossed at 2.2kHz with a first order Jantzen crossover. Buchardt rates in-room bass extension to 33Hz and anechoic sensitivity at 87dB, and includes foam port plugs to trim bass near a wall. Sold direct with free worldwide shipping, duties included, and a 10 year warranty for the first owner.
Cons: No independent measurements have been published yet. The S400 MKII measured very well, but the MK3 shares only its binding posts, so that result can’t be carried over and its linearity, directivity and real bass extension are unknown. The 33Hz figure is an in-room number, not an anechoic one. The MKII’s adjustable passive radiator is gone in favor of a rear port that wants at least 5cm from the wall. A 4 ohm load means it needs an amplifier comfortable driving 4 ohms, and it is sold only direct from Buchardt.
Full Buchardt S400 MK3 review and specifications →
| Crossover Frequency | 2.2kHz (first order) |
|---|---|
| DIY Kit | No |
| Dimensions | 392H x 198W x 280D mm |
| Drivers | 1” aluminum dome tweeter in waveguide, 7.5” Satori Papyrus paper cone woofer |
| Frequency Response | 33Hz - 20kHz (in-room, manufacturer specified) |
| Impedance | 4 ohms |
| Sensitivity | 87dB anechoic, 90dB in-room (manufacturer specified) |
| Weight | 8.5 kg each |
| Woofer Cabinet | ported, rear |
- Links
- Reviews, Comparisons and Sound Samples
- These figures are manufacturer-specified rather than independently measured.
- Head-to-Head Comparisons
KEF R3 Meta: $2,499.99 per pair Amazon Crutchfield eBay
Pros: Three-way design with an unconventional concentric layout: the 1” tweeter is recessed into the throat of the 5.25” midrange driver, deeper integration than a standard coaxial arrangement. A quasi sealed/ported bass alignment gives an extended low-end shelf tuned to match typical in-room gain, reaching about 50Hz for most content: deeper than recently-tested rivals like the Focal Aria 906, Polk R200, and an 8” Aperion design. Spinorama measurements show class-leading directivity and sound power, plus very linear on-axis response (at the recommended 10° toe-out) and early-reflections directivity, so it takes EQ exceptionally well. The vertical sweet spot extends to about ±20-30° off the reference axis with nearly identical tonality, unusually wide for a two- or three-way design. A clear upgrade over the earlier, non-Meta R3, eliminating the treble brightness the original had even when toed off-axis. Outperforms similarly-priced rivals (Revel M106, Wharfedale Linton, Philharmonic BMR V2, JBL HDI 1600) specifically on directivity and linearity in the reviewer’s measurements. At $2500/pair, called the best value in its class with near-reference-level anechoic performance. Measured bass extension of 76Hz (-3dB), with a measured sensitivity of 85.9dB.
Cons: Pointed straight on-axis, there’s a 1-2dB bump around 9kHz that stays consistent across angles thanks to the constant-directivity waveguide: only toeing the speaker out about 10° tames it. Minimum impedance dips to about 3.2 ohms nominal (EPDR as low as 1.9 ohms), so it needs a 4-ohm-stable amplifier; a standard AVR likely won’t cut it. Distortion crosses the reviewer’s 3% threshold around 80Hz at 96dB output and shows added deviation again near 50Hz, indicating it runs out of headroom at higher volumes: a subwoofer is recommended for loud listening. Horizontal radiation narrows from about ±70° at low frequency to ±40° at high frequency. Below about 100Hz, compression testing shows fairly wide deviations at both 86dB and 96dB output, though the reviewer notes this is typical for speakers in this size and price class. Current R3 owners who are already happy with that speaker have little reason to upgrade.
Full KEF R3 Meta review and specifications →
| Bass Extension (-10dB) | 37Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 76Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 16.6”H x 7.9”W x 13.2”D (421.6 x 200.7 x 335.3 mm) |
| Drivers | 6.5” Hybrid aluminum ported woofer, 5” aluminum cone midrange, 1” vented aluminium dome with MAT tweeter |
| Impedance | 4 ohms nominal (3.2 ohms minimum above 80Hz, measured, Erin’s Audio Corner) |
| Sensitivity | 85.9dB (measured, Erin’s Audio Corner; 87dB manufacturer specified) |
| Spinorama Preference Score | 6.10 |
| Spinorama Preference Score with Perfect Sub | 7.91 |
| Weight | 27.3 lbs (12.4 kg) each |
| Woofer Cabinet | ported |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: KEF R3 Meta: The Speaker to Beat. More from Erin’s Audio Corner →
- Erin’s Audio Corner Website KEF R3 Meta Review
- Erin’s Audio Corner: Upgrade Your Sound with These 6 Surprisingly Affordable Speakers!
- Erin’s Audio Corner: My Personal Favorite Speakers Under $2500
- Erin’s Audio Corner: My Top Picks of 2023: Must-Haves Under $3000
- GR-Research: Finally… a Speaker Danny Doesn’t Have to Fix? More from GR-Research →
- New Record Day: The Gold Standard Of "Pretty Good" KEF R3 Meta Review
- Erin’s Audio Corner Measurements (spinorama.org)
- Head-to-Head Comparisons