⌈ The Danish company BUCHARDT AUDIO was founded by MADS BUCHARDT in 2008, but "officially" has been operating since 2013. Its headquarters is located in a small town with a population of just over 40,000 people called Silkeborg. We are testing a limited to 50 pairs version of the S400 model called S400 SIGNATURE EDITION. ⌋

THE AUDIO AND ELECTRONIC INDUSTRY is responsible for Denmark's fourth largest export, after oil-related products and energy production, mainly as a supplier of wind turbines. Side by side, in completely separate bubbles, very strong sections coexist: speaker, microphone (Brüel & Kjær) and those for the hearing impaired (Oticon, GN ReSound). In this country, engineers managed to combine technical solutions with top-class workmanship and design - respect!

Author of the Danish Loudspeakers. 100 years: 1915-2015 says that the "golden period" in audio industry development in this country was between 1957 and 1972. The Peerless brand, one of the most important manufacturers of drivers, developed significantly at that time, and the AudioDyne company was founded back then too, which developed loudspeakers for the Dynaco (A-25), produced by the Norwegian SEAS, and which were sold in an over a million copies! The end of Eldorado came with a fuel crisis in 1973. Paradoxically, it was then that the Danish manufacturers of drivers, such as Scan-Speak, grew into global players, mainly thanks to the innovations introduced to their products.

▌ FROM RABU ACOUSTICS TO BUCHARDT AUDIO

BUCHARDT AUDIO IS IN COMPARISON quite a novice, and yet it also benefits from the achievements of its predecessors, both in terms of technical solutions for loudspeaker applications and the design of drivers themselves. The company was founded by two friends, KASPER RAUNA and MADS BURCHART in 2008 as RABU ACOUSTICS - Kasper was responsible for technical projects, and Mads for their "tweaking" and sales. This initial period witnessed the development of two loudspeaker models, the S200 and S300, with the latter - in the Mk II SE version - is still available today.

In 2013, the partners parted ways and Mads established the Burchardt Audio, that is, a brand under his own name. Initially, he developed concepts that were agreed with his partner, i.e. two-way stand-mount passive speakers, but for some time he has also been offering active speakers, including wireless ones, and recently the I150 integrated amplifier, equipped with an acoustics correction system, was launched.

The break-up of the partners in question was forced by life - Kasper received an irresistible offer from the giant, Dynaudio, where in the following years he designed a large part of its loudspeakers. When his contract ended, he was hired by a subcontractor to many Danish - and not only - driver manufacturers, Hansong, that uses state-of-the-art machines, including one of the few robots of this class in the world for automatic driver measurements.

Mads's former partner did not last long and in his spare time, together with another engineer - Lasse - designed the third model for Burchardt Audio, the S400. It was the first loudspeaker in the world designed using the aforementioned measurement robot.

▌ S400

ONE OF THE MOST IMPORTANT SOLUTIONS OF Burchardt Audio from that time is a large element visible in front of the S400 and S400 Signature Edition tweeter - it is a waveguide used to shape the sound wave. In itself, it is nothing new, let me remind you that the waveguides are used also by such firms as AMPHION, where it is called ‘Waveguide Integrator’, AEQUO AUDIO with their ‘EHDL Waveguide’, or REVEL, in which we can find ‘Acoustic Lens Waveguide’.

However, as in the case with horns, the geometry of the waveguides is often significantly different. This element is designed to shape the directivity of wave propagation from the tweeter so as to align the loudspeaker's response off the main axis and to best integrate its work with mid-woofers - therefore they usually (although not always) have a diameter similar to the latter.

The introduction of the waveguide in the S400 was the most important difference between it and the earlier S200 and S300 models. The second was the addition of a stadium-shaped passive driver to the back panel. This is how the two-way stand mount model with an inverted configuration of the drivers was created - the tweeter was placed below the mid-woofer - with a passive driver instead of a bass-reflex port. The loudspeaker was relatively small, it measured 375 x 180 x 245 mm (height x width x depth), and it was available in white and black.

▌ S400 SIGNATURE EDITION

THIS PROJECT WAS SO SUCCESSFUL that Mads decided to show what it could do, if he had no financial constraints. Because an audio product consists of many different elements, among which the economic bill is as important as the technical design. And the former always, there are no exceptions, dictates some of the choices. The owner of Burchardt Audio behaved like a pure audiophile, modifying the product that is extremely close to him.

A few simple words…

MADS BURCHARDT
Owner

WOJCIECH PACUŁA Why did you develop the Signature Edition?
MADS BURCHARDT Before Buchardt Audio existed, we actually came from a DIY speaker shop that we started back in 2008. We know the importance of crossover components, something that is often overlooked as customers can't see it. But the crossover is one of, if not the most important part of a passive speaker. Both its design and choice of components. The Signatures were a speaker where we went more crazy with bespoke parts in the crossover, wires and terminals. And we wanted this model to be made in Denmark as well, and in small batches with a new finish for each batch. 

WP How much better is the SE version compared to the „regular” one?
MB That is a very hard question to answer as that depends so much on how resolving your system is, and how good your room is as well. No doubt it's better, some customers think it's a huge upgrade, others not. So it is very much a personal question. 

WP What are your future plans?
MB Next we have planned are 2 more batches of Signatures in two new exciting veneers. People would have to wait until they are announced to see :)

WP What kind of music do you listen for pleasure?
MB I listen to a wide selection of music. Mostly acoustic, folk, classical, rock. But also electronic and ambient music. ♦

The SIGNATURE EDITION of the S400 is externally very similar to the base model. It is a medium-sized stand mount speaker with sloped front and rear baffles. Its nominal impedance is 4 Ω and its efficiency is 88 dB, so it requires a powerful amplifier. The manufacturer himself recommends a useful range between 40 and 200 W. I would treat the first value as an absolute minimum. The loudspeakers have a wide frequency response, which, according to the manufacturer, ranges from 33 to 40,000 Hz, with a drop of -3 dB (in a typical room); the crossover point is 2000 Hz.

Despite the similarities, the first difference is immediately visible - a high-class, really beautiful-looking wood veneer in gray oak (Graphite Oak) was used here, with a matte finish and varnish pleasant to the touch. Another difference will be clear when we take the speakers in hand - they are a bit heavier than the S400 and seem more solid. This is because the walls are made not of MDF (medium-density fibreboard), but HDF (high-density fiberboard), i.e. denser and stiffer material.

The most important, I believe, change is not immediately apparent. It is indicated by the outstanding, amazing-looking and comfortable-to-use speaker terminals on the rear panel. In place of the good, but in comparison simply bland, terminals used in the basic version of these loudspeakers, we get terminals made by another Danish manufacturer, the ARGENTO AUDIO. They were bolted to a brass nameplate with the serial number of a given pair - let me remind you that there were only 50 of them made.

Specializing in cables, established in 1991 by ULRIK GYDESEN MADSEN, Argento Audio presented its first cables in 2003. It focuses on silver conductors, and its speaker terminals can be found in the top products of Tidal, Amphion and CH Precision. These terminals feature silver contacts - so that the signal is sent through the same conductor, the internal wiring of the tested loudspeakers is also made using Argento Audio cables.

The most important difference, however, is not visible at all - the S400 Signature Edition is equipped with a completely different crossover. Responsible for it is another well-known Danish company, JANTZEN AUDIO . All inductors in this version are burnt air coils, thanks to which a low distortion is achieved, and the resistors used in it have a tolerance of 1%. The capacitors are also great. These are exclusively polypropylene models from the Cross-Cap and Superior Z-Cap series.

However, it is still quite a classic monitor, with a 19 mm soft silk dome and a 145 mm mid-woofer with an aluminum diaphragm, reinforced with embossing. As we mentioned, the tweeter is loaded with a waveguide with a diameter of just over 150 mm, made of aluminum.

On the back you can see an interesting transducer - a passive diaphragm in the shape of a stadium. Drivers of this shape were known in the 60s and 70s, and the most important company that used them was the British KEF. Nowadays, people return to them, an example of which - apart from Burchardt Audio - are the loudspeakers from DEFINITIVE TECHNOLOGY. The specimen used in the tested loudspeakers has dimensions of 130 x 200 mm, a paper diaphragm, a rubber suspension allowing for a large throw and an embossed, sheet metal basket.

▌ STANDS

The S400 SINGNATURE EDITION loudspeakers are fantastically made. By looking at them and touching them, we know that we are dealing with high-class engineering. Color and details have been selected in such a way that the speakers perfectly reflect the Danish hygge spirit. As we read in Wikipedia, 'hygge' is a Danish word for comfort, coziness, and used to describe achieving inner balance, security and happiness, especially by Scandinavian societies. The concept was born in Denmark in the 19th century and is considered the equivalent of the French joie de vivre.

In order not to destroy this impression, it is worth buying the tested speakers with specially designed Buchardt Audio Stands. Costing PLN 899 apiece (in Poland), they are in the form of tripods and are available in several colors. We, regretfully, received the tested pair of speakers without them, but you just MUST see and listen to the complete set, i.e. the speakers and bespoke stands.

▌ SOUND

⸤ HOW WE LISTENED Buchardt Audio loudspeakers were tested in the "High Fidelity" reference system and compared to the Harbeth M40.1 loudspeakers. They stood at a distance of 1850 mm from each other, counting from the tweeters, 90 cm from the rear wall (counting from the rear wall of the speakers) and 80 cm from the ACOUSTIC REVIVE RWL-III ABSOLUTE panels set on the side; I took the measurements with a Bosh PLR 50 C laser meter. The speakers were toed-in so that their axes crossed slightly in front of the listening position.

The S400 Signature Edition was driven by the Soulution 710 power amplifier using silver Siltech Triple Crown cables. The Argento Audio speaker terminals fit perfectly with the silver spades the Siltechs are terminated with (their cables are fused with the spades, they form a whole). As the bespoke Buchardt Audio Stands were not available during the test, I listened to the loudspeakers using the old Sonus faber stands.

Recordings used for the test | a selection

→ COMPACT DISC
⸜ MAROON5, V, Interscope Records/Universal Music LLC (Japan) UICS-9146, CD + DVD (2014);
⸜ PORTISHEAD, Dummy, Go! Disc Limited/Universal Music Company [Japan] UICY-20164, SHM-CD (1994/2011).
⸜ RÖYKSOPP, The Inevitable End, Dog Triumph DOG013CDW, „Promo | No. 25”, CD-R (2014).
⸜ SUZANNE VEGA, Nine Objects of Desire, A&M Records 540 583 2, CD (1996);

→ AUDIO FILES
⸜ BILLIE HOLIDAY, Billie Holiday With Ray Ellis And His Orchestra, MGM Records MGM-C-792/Tidal Master, MQA 24/96 (1959/?).
⸜ FRANK SINATRA, Frank Sinatra: Reprise Rarities Vol. 3, Sinatra Enterprises | UMe/Tidal, FLAC 16/44,1 (2021).
⸜ GEORGE BENSON, Guitar Man, Concord Jazz CJA-33099-02/Tidal 16/44,1 (2011).
⸜ SACHAL VASANDANI & ROMAIN COLLIN, Midnight Shelter, Edition Records/Tidal Master, MQA Studio 24/96 (2021).

THE SMALL BUCHARDT AUDIO S400 Signature Edition loudspeakers sound incredibly spacious. I start with this aspect of their sound because it is incredible, simply outstanding. The powerful Harbeth M40.1, which I use every day, are better in this respect, but only because using lower, bigger bass they can build a deeper and more massive soundstage. When it comes to stereo, it is how wide and how deep something will be shown, small boxes from Denmark rule.

And even if we start listening session not with some fancy audiophile gems, but with classic tracks, such as Caramel from the Nine Objects of Desire by SUZANNE VEGA, or - beautifully presented - Here She Comes Again from the farewell album of the RÖYKSOPP duo entitled The Inevitable End. It struck me particularly hard with the first one, when the guitar sounded behind the left speaker, along its outer edge, and the tambourine entering at some point sounded gentle but clear, coming from behind the right speaker.

These sounds were not connected with the speakers themselves, it was rather like with the reference speakers. The presentation arose in front of me with no apparent connection to the speakers, as if it were generated by invisible machinery hidden behind the back wall. It is obvious that when the signal is more compressed, as it was in the track Running To The Sea from Röyksopp's album, the depth will be conventional, and the whole presentation will focus on the line connecting the speakers. Even then, it will be something "next to" the speakers, it will not be attached to them.

The Danish loudspeakers are able to maintain an extremely stable center of presentation, suggesting particularly well-reproduced phase relations between the drivers. The debut album recorded in lo-fi aesthetics, entitled Dummy, an album of the trip-hop band PORTISHEAD, with an almost monophonic sound, whether from Wandering Star or in a beautiful, ending album Glory Box had a fantastically presented structure. The depth dimension was above average in its stability and scale.

Because these are loudspeakers with big sound. To confirm these observations, I reached for the latest, third part of FRANK SINATRA's "rarities" from the Reprise label. Recorded with a large orchestra, with strings in the left channel, wind instruments in the right and percussion usually in the middle, they were reproduced in a big, powerful way, with momentum and breath. These are not loudspeakers that would choke, even at low volume levels.

But even if a single instrument is playing, let it be GEORGE BENSON's electric jazz guitar from the Guitar Man album released in 2011, the loudspeakers will show it in a big, strong and filled way. It was similar with the vocals and piano from the Midnight Shelter by the SACHAL VASANDANI and ROMAIN COLLIN duo. The voice was shown fairly close to me, but without breaking my comfort zone, that is, without being intrusive.

Already with the The Inevitable End album I noticed how deep the loudspeakers go with the bass. The presence of a large driver on the rear panel could suggest something like that, but on the other hand, the lack of bass-reflex, which always adds some kind of filling at the bottom, could dissuade such a conclusion. It turns out that the design of the S400 SE allows them to convey the low bass, without overextending it. It is deeper and more "sticky" internally than in loudspeakers with a closed cabinet, which is an advantage, and it is not less dynamic or slower because of it, so - an advantage and an advantage.

It can even be said that the entire sound of the tested components is based on mid-bass and low midrange. Unlike usually in this case, these are not warm or even “sweet” loudspeakers. Their timbre is open and they carry a lot of energy in the middle of the band and its upper end. I heard it right at the beginning, on the Suzanne Vega album, and it was still there when listening to Röyksopp and Portishead, and then BILLIE HOLIDAY and JIM HALL.

The point is that nothing here will be covered up or "straightened up". So the loudspeakers require a top-quality system and recordings that have that "something" that makes the music have an inner sense. It does not matter what music genre we are talking about, the S400 "don’t care" but rather about the music and its class. Let me add that they show a fairly strong, slightly "punchy" upper midrange, which could be slightly softened with the appropriate selection of electronics or cabling.

▌ SUMMARY

I STARTED DESCRIPTION OF THE S400 Signature Edition Loudspeakers by drawing attention to their flawless spatiality, then I showed the scale of their sound and well-guided bass. Not everyone will like the opening of the sound, but this is not a problem with loudspeakers, but recordings. The tested model is extremely resolving. It does not hide anything, does not dance a mating dance in front of us, but rather communicate things "as they are".

The resolution in question, and thus the differentiation, puts them in a place where we can talk about "monitors". They could work pretty good in a sophisticated recording studio as near-field monitors. They show a lot of details, but are not detailed by themselves, that is, they are not an end in themselves. They are extremely dynamic and resistant to distortion, which is why their sound is extremely effortless. These are loudspeakers for high-class systems in which they will probably be the cheapest component. ■

Technical specifications (according to the manufacturer)

Design: 2-way, passive
Tweeter: ø 0.74", Custom fine weave soft fabric textile with CDC aluminum waveguide
Mid-woofer: ø 6", aluminum
Passive radiator: 1 x 5x8", Long throw passive radiator with very low mass added
Nominal impedance: 4Ω
Sensitivity: 88dB
Frequency range: 33 - 40 000Hz, +/-3dB (in a room)
Crossover point: 2000Hz
Power recommendation: 40 - 200W
Dimensions (H x W x D): 375 x 180 x 245 mm
Weight: 9.5 kg
Colour: Graphite Oak