Hardware Reviews

Buchardt S400 MkII: high end for less

Buchardt S400 MkII loudspeaker review www.the-ear.net

Buchardt S400 MkII loudspeakers

I faced an awkward dichotomy in deciding when to pen this review because, while eager to share news of a very exciting product I am aware that, once published, the review samples will have to be shipped back to the manufacturer and I would like to enjoy them for as long as possible. But I can no longer restrain my thoughts on the Buchardt S400 MkII bookshelf speakers.

This Danish company was founded by Mads Buchardt in 2013, his audio roots date back to Rabu Acoustics in 2008 since when he has engaged developers and engineers in a quest to create good-sounding audio products at an affordable price. The Buchardt loudspeaker range is the product of a long and meticulous design process with a focus on compact, discreet Nordic design.

Buchardt adopts an unusual supply chain with no distributors or high street retailers. Instead, they sell direct to end-users. It’s a model which others have tried, to varying degrees of success, but so far selling high-quality products at a really competitive price seems to be paying off. Doubtless Covid lockdowns saw more consumers turning to the internet to source a wide range of things which they would probably have gone out shopping for. Another aspect that keeps prices highly competitive is a design in Denmark with manufacture in Indonesia approach, passing on at least some of the savings made over construction in more expensive labour markets. Added to which, Buchardt offers a ten-year manufacturer’s warranty on the S400 MkII as with all their speakers.

Buchardt S400 MkII loudspeaker review www.the-ear.net

I had heard great things about the S400 from various quarters on my travels to hi-fi shows and was excited that the loudspeaker has been relaunched in Mk II form this year. It has been redesigned with a highly improved crossover, cabinet and a new paper-cone woofer. It also relies on a huge passive radiator to deliver deep and controlled bass.

The S400 MkII is said to work well in all room types (presumably a reference to both heavily-damped and lively acoustics), as well as benefiting from easy placement thanks to the CDC waveguide which, as I discovered, gives an off-axis response almost as good at that on-axis. Buchardt feel that the design can be used in both audiophile as well as professional applications.



The cabinet is constructed from 15mm moisture resistant fibre-board with internal bracing to reduce or re-direct resonances out of the critical audio band. I found the stylish matte white finish contrasted well with the black drive units and fitted in to my domestic environment. There are many other paint, as well as real wood veneer, finish options.

Buchardt S400 MkII loudspeaker review www.the-ear.net

The tweeter is placed, rather unusually, under the mid/bass driver. It is a tiny tweeter but looks much larger due to the aluminium waveguide. Where we might expect a driver of between 25-29mm, the S400 MkII has a 19mm dome. This was chosen because while a larger unit would have higher power handling and wider bandwidth (so the crossover point can be lower) the off-axis response tends to suffer with an uneven response at high frequencies.

The design was extensively researched, including prototyping and use of a holographic nearfield scanner that measures 5,402 points around the speaker. In this way, engineers can discover how the speaker behaves from all possible angles which was a key facet to creating a waveguide which matches the contour plot of the woofer down to 1kHz, effectively making the tweeter and woofer work as ‘one driver’ at the crossover point.

In the S400 MkII model we see a new paper-coned mid/bass unit designed by the Danish guru Ulrik Schmidt, this replaces the aluminium unit found on the original model. I have always been a big fan of paper-drivers because of the superb midrange they can reproduce, although more often than not at the expense of bass response. So Buchardt has opted for a mix of natural fibres in its proprietary cone to increase stiffness in this long-throw woofer. A soft, low-damping rubber surround has been optimised for the best transient response, while a non-conducting, fibreglass voice coil former was chosen to minimise damping. There is an extended copper sleeve on the pole-piece for lower inductance and improved distortion figures, and a vented pole-piece for reduced compression.

Buchardt S400 MkII loudspeaker review www.the-ear.net

Careful attention was also paid to phase aligning the drivers which is why the tweeter/waveguide is below the woofer and the cabinet angled slightly backwards. Other details included making sure that the edge diffractions from the cabinet were reduced by 90%; the result of a small tweeter and a very deep waveguide.

The S400 MkII crossover has seen major revision from the earlier Mk I and boasts high-end components following intensive work on capacitor/resistor options. In the end, the choice was ultra-high-end CU/paper/oil capacitor from Miflex mixed with amazing parts from Jantzen Audio Denmark namely their Cross-caps, baked air-core inductors and Superes resistors. Those oversized air inductors are something special, wound with thick 1.6mm high-purity copper wire in an effort to achieve an undistorted sound. Internal wiring and even the circuit board also benefit from an upgrade in the revamped design.

Most of the rear panel is taken up by a large long-throw passive radiator measuring some 127 x 203mm which is used instead of a reflex port to extend the bass response down to a claimed 33Hz. Also to the rear is a pair of single wire connection terminals. Firmly anchored to a pair of Custom Design FS104 Signature stands, the S400 MkIIs were hooked up to my trusty all-in-one Hegel H190 which proved a very happy combination. I opted to leave the detachable grilles (two per cabinet) in the box, if only because I forgot about them until it came to packing the speakers up. They would provide protection to the drive units but, sonically, I didn’t feel they were necessary.

Sound quality

Set-up was straightforward, placement easy from this unfussy design, and amplifier matching a doddle from what seems a friendly load for the electronics. Indeed, even with that large passive radiator I was able to position the cabinets just 15-inches (38cm) from the rear wall without any undue effect.

Buchardt S400 MkII loudspeaker review www.the-ear.net

For me, it is a loudspeaker’s midrange that is the crucial area; I have used traditional BBC monitors in a raft of studio and OB setting across several decades so this has become ingrained. In this regard, the Buchardts passed with flying colours across a wide range of material from speech-based drama recordings to live TV and radio as well as both female and male vocalists including Bardo’s One Step Further and Alison Moyet’s Is This Love where the speaker’s timing credentials were also cemented.

Naturalness is key for me and I am happy to report that the S400 MkII scored very highly in this area; managing to avoid a full or throaty midrange in favour of something much more natural thanks to a reasonably flat tonal response. I know that the design team made this one of their key objectives, and they’ve pulled it off because human voices sound so realistic and possess just the right amount of presence, without sounding hard or thin as so many modern loudspeakers seem to. The clarity was noticeable for more than one panel member on Mozart’s The Marriage of Figaro (Charles Mackerras on Telarc from 1994) where Alastair Miles and Nuccia Focile could have been just a few feet away as the ambience of the recording was literally brought home.

One really noticeable facet of the S400 MkII is how the off-axis performance is nearly as good as on-axis. This means we are getting evenly distributed in-room frequency response, showing itself in exemplary imaging, a bigger soundstage, and better transparency. The soundstage was indeed huge, notably so given the modest cabinet dimensions. The width and depth (depth especially) appeared pronounced on many recordings, notably a near-3D re-creation of Handel’s Water Music (the English Baroque Soloists under Sir John Eliot Gardiner). It was possible to close one’s eyes and be transported to the 1991 lively tempi recording of those brazen horns and sparkling trumpets truly something special.

Buchardt S400 MkII loudspeaker review www.the-ear.net

Dynamics are another of the speaker’s strong points but again while maintaining a natural presentation, rather than falling for the modern practice of projecting the soundstage forward into the listener’s lap in a most unnatural fashion. Such restraint allows space for the soundstage to generate its depth and dynamics. Not only does this make for a more engaging experience, as Buchardt note, but also to my mind is much more likely to be what the recording engineer was trying to create. Certainly we enjoyed JS Bach’s rousingToccata and Fugue in D minor (Gerhard Weinberger on CPO from 2000) which put a smile on everyone’s faces thanks to the full-bodied rendition. It is on works such as this that the speaker’s bass credentials shine. Not only is this one the biggest-sounding designs of its size that I’ve heard but its ability to reproduce, with such proficiency, lower registers from a cabinet which seems to defy the laws of physics, is just remarkable.

I used the S400 MkIIs every day for several weeks and never tired of what they could achieve. I had them either side of a large screen TV as they handled every type of material thrown at them, from live recitals, more raucous concert streams, dramas, serials and discussions. I would therefore class them as consummate all-rounders.


The sales model used by Buchardt is a risky one. It has been tried before with varying levels of success. Bypassing both distributors and high street dealers removes two sales margins from the final price, the fact that Buchardt has been using it successfully for over a decade is also a good sign. However, it does mean that the manufacturer has to work incredibly hard to fulfil the roles of those being omitted from the supply chain.

Buchardt S400 MkII loudspeaker review

During, and since, the Covid pandemic I know that more and more of us are choosing to shop online, direct from source. Whether that is sustainable, and what effect it will have on traditional high streets remains to be seen. But Buchardt has clearly given the matter a great deal of thought before opting for this route. The idea of a free home-trial period and a no-quibble money-back guarantee if the product fails to please looks like something of a winner to me.

If only all loudspeakers could be made to this standard there would be no need for reviewers to select the wheat from the chaff. We have here a delightful product which is the result of highly-competent engineering in both design and manufacture. If the fact that Buchardt offer a ten-year warranty was not proof enough of their confidence in the product, I have no hesitation in thoroughly recommending the S400 MkII as an audiophile product of not only tremendous quality but also offering incredible value.


Type: reflex loaded 2-way standmount loudspeaker
Crossover frequency: 1.8kHz
Drive units:
Mid/bass: 6″ Linear long stroke paper cone
Tweeter: 19mm custom-made fine-weave soft fabric textile
Nominal frequency response: 33Hz – 40kHz +/- 3dB (in-room)
Nominal impedance: 4 Ohms
Connectors: binding posts
Sensitivity: 88dB @ 2.83v/1m
Dimensions HxWxD: 365 x 180 x 240mm
Weight: 7.5kg
Finishes: painted or real wood veneered
Warranty: 10 years

Price when tested:
Buchardt Stands €450
Manufacturer Details:

Buchardt Audio


standmount loudspeakers


Trevor Butler

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