Buchardt S400 MK3 is a 2-way Passive Bass Reflex Bookshelf speaker by Buchardt. It was released in November 2025. It features a 1" waveguide Tweeter and 1 x 7.5" SB Acoustics Satori Egyptian Papyrus papercone Woofer. The speaker has a frequency range of 33-20k Hz and a sensitivity of 87 dB. Buchardt S400 MK3 has an MSRP of 2300$ per pair.
Room Size Suitability
The size of the room where you plan to use the Buchardt S400 MK3 is a crucial factor in your decision. We have assessed its suitability for various room sizes based on its dimensions and maximum power output:
| Listening Environment* |
Suitability |
| Near-field | Poor |
| Small Room | Average |
| Mid-size Room | Good |
| Large Room | Average |
| Very Large Room | Poor |
(* Approximate Room sizes: Small < 100sq. ft / 9 m2, Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: > 400 sq. ft / 36 m2.
Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual listening experience changes depending on floor height, room shape, surface materials, listening position, speaker locations, etc.)
Buchardt replaced the older S400 MKII with this model. Follow the link to read our detailed comparison of these models:
Compare Buchardt S400 MK3 vs Buchardt S400 MKII
Buchardt's Passive Series of Loudspeakers
S400 MK3 is a member of Buchardt's Passive series of Passive speakers. Buchardt's Passive range are traditional passive loudspeakers built with premium drivers and cabinets, sold factory-direct at prices that undercut dealer brands. Below you can see the main specs of these speakers.
See all 6 Buchardt Passive models compared »
Buchardt Passive Series Speakers
Frequency Response of the Buchardt S400 MK3 Speaker
Buchardt S400 MK3 has a Frequency response range of 33-20k Hz at -3dB and Power Range of 30+ watts. With a minimum frequency of 33 Hz, S400 MK3 delivers deep bass that will likely satisfy most listeners, especially those who enjoy music. However, movie enthusiasts and music fans who prefer a full range of sound may still benefit from adding a subwoofer.
Here we have a comparison of how S400 MK3's Low frequency value compares with the average, max and min Low frequency values in its class.
Low Frequency
Bookshelf Speakers
Thinking about a subwoofer for the Buchardt S400 MK3?
Crossover frequency of the Buchardt S400 MK3?
The crossover frequency of the S400 MK3 is set to 2200Hz. This is the threshold frequency where the higher frequency signals over this level are sent to the tweeter and the lower-frequency signals are sent to the woofer by the crossover component.
Impedance and Sensitivity
Buchardt S400 MK3's nominal impedance level is
4 ohms and has a sensitivity of
87 dB.
Sensitivity
Bookshelf Speakers
Nominal Impedance of the 4 Ohms means that the Buchardt S400 MK3 is a difficult to drive speaker from nominal Impedance perspective, make sure that you choose an amplifier than can provide 4 Ohms for this speaker.
Many AVRs (audio/video receiver) in the market may have difficulty when the speakers dip below the 4 Ohms levels (this may cause clipping or even physical damage), so we recommend to not pair the Buchardt S400 MK3 with an AVR but use an Integrated Amplifier instead.
Sensitivity
With a sensitivity level of only 87 dB, Buchardt S400 MK3 is a difficult to drive speaker from Sensitivity perspective, make sure to choose an amplifier with a high output if you like listening to your music at high volume levels. You may especially have a hard time using Tube amplifiers which are traditionally very low power compared to Class A/B or Class D amps. Work out how loud the Buchardt S400 MK3 plays in your room →
Running more than one pair from a single amplifier? Check the load it would present →
What amplifier does the Buchardt S400 MK3 need?
At normal listening levels in a medium room, about
30–30 W
per channel into 4 ohms.
Set your own conditions and we will rank every amplifier we cover.
Prefer to browse? Integrated amplifiers under $3,000, or every amplifier we cover.
Input Type
S400 MK3 features type connectors.
Buchardt S400 MK3 External Dimensions and Weight
Buchardt S400 MK3 has external dimensions of (Height x Width x Depth) 15.4 x 7.8 x 11 inch (392 x 198 x 280 mm ).
Base Surface Area
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base area of Buchardt S400 MK3 is approximately 554.4cm2 / 85.9inch2.
Find speakers that fit your shelf or alcove → · Work out where they should sit in the room →
WeightThe Buchardt S400 MK3 weighs 8.50kg / 18.7lbs per piece. Here is a comparison of how S400 MK3's weight compares with the average, max and min weights in its class.
Weight
All Bookshelf Speakers
Weight
Bookshelf Speakers under $3000
Cabinet type and Materials
Buchardt S400 MK3 has a
Bass Reflex type cabinet and a 15mm HMR.E2 moisture-proof fiberboard finish. Bass Reflex type loudspeakers (aka Ported, Vented or Reflex Port) have enclosures that uses a port, hole or vent cut into the cabinet. Ported designs are generally more efficient than the Sealed designs.
Available colors
Buchardt S400 MK3 is available in Black, White, Walnut and Natural oak.
Wall Mounting
S400 MK3 doesn't sport any built-in mounting bracket, so you need an external structure to mount it on walls.
Speaker Stands
Buchardt sells a dedicated speaker stand for the S400 MK3 with a model name
Buchardt Stands. You can check the latest price and availability of these stands at
B&H PHOTO and
Amazon.
Does the Buchardt S400 MK3 come with a Grille?
S400 MK3 comes with grilles. The purpose of the grille is to protect the delicate driver elements from external impacts while still allowing the sound to pass as clearly as possible.
Recommended Accessories
Here is a list of accessories that we think you may need for the Buchardt S400 MK3.
- Speaker Cable and Connectors
- Vibration Isolators: IsoAcoustics isolators are our favorite isolators but you may find more affordable options too.
- Acoustic Panels and Treatments: Your room is as important as your stereo equipment so acoustic treatments goes a long way in improving the overall performance.
- Speaker Stands: Stands bring your bookshelf speakers to ideal height (rule of thumb is to have the tweeter level with your ear in your listening position), helps stability and acoustical isolation.
Sales, Return and Warrant Policy
Buchardt sells its speakers only via its
official website and doesn't use any dealers. Eliminating the middleman helps the company to keep the costs down. Shipping is free anywhere in the world (including all tax and import costs) for orders over 850 Euros. They have a 45-days return period, you can decide to return the product for any reason but there is a 100/200 Euro return fee (Please check their official website for most up to date information).
Official Product Page
Official manufacturer's product page for the Buchardt S400 MK3 speaker can be found below:
Official Product Page for Buchardt S400 MK3
Warranty
10 years of parts warranty and 10 years of labor warranty is generally provided by the manufacturer.