Short answer: the Buchardt S400 MK3 is the newer model that replaces the Buchardt S400 MKII, but only the Buchardt S400 MKII has been measured and ranked so far, so this comparison is on specs and features rather than sound. The Buchardt S400 MKII is discontinued, so it is now a used buy.
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 Buchardt S400 MKII side: Two-way design with a 3/4” tweeter on a well-implemented aluminum waveguide (compression-driver style, letting the small tweeter cross unusually low at 1800Hz), a 6” SB Acoustics-style mid-woofer, and a tunable 5x8” passive radiator adjustable via rear weights.
On paper: The Buchardt S400 MK3 is more sensitive, 87dB against 84.7dB, so it needs less amplifier power to play loud.
Price: the Buchardt S400 MK3 lists at $2,300 and the Buchardt S400 MKII at $2,400.
Buy the Buchardt S400 MKII if you want a speaker whose sound quality has been measured and ranked.
Buy the Buchardt S400 MK3 if you want the newer model, with higher sensitivity, and you can wait for measurements to confirm how it sounds.
Looking for alternatives? See the complete Passive Home rankings.
Specifications Side By Side
| Buchardt S400 MK3 | Buchardt S400 MKII | |
|---|---|---|
| Price | $2,300 per pair | $2400 per pair Discontinued |
| Ranked | - | #64 of 131 in Large Size Bookshelf Speakers |
| Crossover Frequency | 2.2kHz (first order) | - |
| Dimensions | 392H x 198W x 280D mm | 14.4”H x 7”W x 11”D (365.8 x 177.8 x 279.4 mm) |
| DIY Kit | No | No |
| Drivers | 1” aluminum dome tweeter in waveguide, 7.5” Satori Papyrus paper cone woofer | 6.5” aluminum cone woofer, 1” soft dome tweeter |
| Frequency Response | 33Hz - 20kHz (in-room, manufacturer specified) | - |
| Impedance | 4 ohms | 4 ohms nominal, 3 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | 87dB anechoic, 90dB in-room (manufacturer specified) | 84.7dB (measured, Erin’s Audio Corner; 87dB manufacturer specified) |
| Weight | 8.5 kg each | 16.5 lbs (7.5 kg) each |
| Woofer Cabinet | ported, rear | ported |
| Bass Extension (-10dB) | - | 40Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-3dB) | - | 59Hz (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | - | 5.38 |
| Spinorama Preference Score with Perfect Sub | - | 7.46 |
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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
Buchardt S400 MKII: $2400 per pair Discontinued Buchardt Audio eBay
Newer model: the Buchardt S400 MK3. It’s likely to perform similarly, though we can’t confirm that yet.
Pros: Two-way design with a 3/4” tweeter on a well-implemented aluminum waveguide (compression-driver style, letting the small tweeter cross unusually low at 1800Hz), a 6” SB Acoustics-style mid-woofer, and a tunable 5x8” passive radiator adjustable via rear weights. Exceptionally flat on-axis linearity, within about ±2dB from 80Hz to 16kHz. Wide horizontal radiation for a waveguided design (about ±45-50°), notably broader than a comparable narrow-waveguide rival like the Klipsch Sevens (~±30°). Well-focused, precise imaging, aided by tight pair matching between the two speakers. Takes very well to EQ correction, letting listeners easily dial in the top end or add midrange fullness to taste. Bass extension reaches a genuine 50Hz in-room from a mellow, well-tuned rolloff rather than an artificially boosted one. Measured bass extension of 59Hz (-3dB), with a measured sensitivity of 84.7dB.
Cons: Sounds a bit bright and slightly boosted above about 7-8kHz on-axis, even with 30° of toe-out: benefits from about 1 inch of sidewall absorption at the first reflection points to tame it. A mild dullness noted especially on male vocals, alongside a small dip around 300-600Hz. Vertical positioning is critical and unusually “temperamental”: sitting even slightly toward the tweeter line causes a suckout, while sitting above it adds too much energy; not well suited to multi-height home theater seating. Distortion is fine at 86dB but runs into real issues by 96dB: not a high-output speaker. Some compression-related enhancement appears around 1.2kHz (crossover-region interaction), and the tweeter shows clear compression at 102dB. The woofer can bottom out at extreme low-frequency content played very loud; crossing to a subwoofer below 60Hz caused output problems at high volume, while 80-100Hz worked well. A subwoofer isn’t strictly required to protect the speaker at moderate listening levels (80-85dB at 3 meters), but is still recommended for genuine low-octave extension. Discontinued.
Full Buchardt S400 MKII review and specifications →
| Bass Extension (-10dB) | 40Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 59Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 14.4”H x 7”W x 11”D (365.8 x 177.8 x 279.4 mm) |
| Drivers | 6.5” aluminum cone woofer, 1” soft dome tweeter |
| Impedance | 4 ohms nominal, 3 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | 84.7dB (measured, Erin’s Audio Corner; 87dB manufacturer specified) |
| Spinorama Preference Score | 5.38 |
| Spinorama Preference Score with Perfect Sub | 7.46 |
| Weight | 16.5 lbs (7.5 kg) each |
| Woofer Cabinet | ported |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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- Buchardt S400 MKII vs ELAC Debut 3.0 DB63
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