I lived with a pair of S400mkII for about 6 months (long term loan from Mads) and I had no preconceptions or expectations except that they wouldn’t perform as well as the Meridian DSP5200.2 DSP active floorstanders that they replaced.
I was very wrong. I’m a big fan of measurements as a way to assess audio products, and the Buchardts do appear to measure quite well. My subjective impression of these speakers is that they are extremely musical and convey music/singing in a very pleasing way compared to many speakers I’ve heard over the years. For example, nothing in the technically superb Meridian Audio range comes close to the S400mkII for musicality and connecting you emotionally to the content. The S400mkII is a speakers that focusses on the midrange. Subjectively they convey the natural “tone” of instruments very realistically and this was somewhat of a party trick when demonstrating them to guests. Even non-audio types commented on how realistic they sounded. A musician friend particularly enjoyed how they reproduced acoustic guitar.
They place sounds slightly in front of the plane of the baffles, bringing the instrument/voice into the room with a real sense of the performer actually being there as opposed to creating a facsimile of the acoustic space behind the speakers with instruments portrayed within it as some designs do. The high frequencies are what some may describe as sweet. I think they are balanced perfectly for delivering huge amounts of details whilst never becoming fatiguing. The bass is very deep for a speaker of its size and I found they can be placed very close to the wall without becoming boomy.
I tried three amplifiers with them. Buchardt’s own amp which is very powerful but I found too bright and lacking weight to the sound. This could be attributed to the ADC and DAC possibly as well as the amplifier design. I tried a Primare A25 which was a very good match. Loads of control and very refined. I also tried them with a Waversa WSlim Lite which was quite awful sounding to my ears. Again could be attributable to the internal ADC/DAC. With the Primare I used a Meridian 218 DAC. The other two amps I used with their digital inputs or their analogue inputs with went through ADC. So not a fair test. However I would say with confidence that the S400mkII require an amplifier with plenty of power (at least 100W) and plenty of current delivery.
The S400mkII are not a monitor speaker although they are highly revealing. For me they are an almost perfect example of a “hifi” speaker in that they add some kind of flavour to the sound that somehow (hopefully measurable) makes music sound beautiful and enjoyable and addictive (they have a very coherent sound with excellent separation and what HIFI people would call good timing). I have listened to a lot of speakers over the years and these may well be the most enjoyable I have heard regardless of price. When funds permit I will purchase a pair to keep.