Steve Huff heard deeper bass on some tracks from the S400 MkII, a small stand-mount, than from his own Fleetwood speakers. Steve Guttenberg says "I love that speaker" and kept it as one of his references. Buchardt builds compact speakers that play far deeper than their size suggests. The key is a passive radiator, a cone with no motor of its own that moves with the air pressure inside the box. It does the job of a bass port, and Mads Buchardt says a ported S400 would need a noticeably bigger cabinet. Up top, a waveguide shapes the tweeter's sound to match the woofer's, and Trevor Butler of The Ear writes that this makes tweeter and woofer work as "one driver." He found the soundstage huge for the cabinet size. Buchardt suits listeners in ordinary rooms who want floorstander bass from a stand-mount.

The S400 MkII is the one to start with, and it wants a capable amplifier. John Alex Hvidlykke of LB Tech Reviews recommends plenty of power, and Butler found a Hegel H190 "proved a very happy combination." The smaller P300 needs the same care. Steve Huff says it sounds best with at least 100 watts per channel, and Guttenberg calls a foot from the wall behind the bare minimum and heard it sound better farther out. The step up is the active Anniversary 10, which has its own amplifiers built in. Guttenberg found it more transparent than the S400 MkII, with deeper and tighter bass, while the S400 MkII was more relaxed and kinder to harsh recordings. The A10 also takes Mastertunings, sound profiles loaded from a USB stick for setups like wall placement or use with a subwoofer. Mads Buchardt told Gordon Brockhouse of SoundStage! Simplifi that the Nearfield tuning was "my favorite tuning—for far field too." Buchardt sells direct with a 45-day home trial, so you can hear them in your own room.

Mads Buchardt is a musician who spent seven years selling instruments in a music shop. In 2008 he and his childhood friend Kasper Raun opened RABU Acoustics, an online shop for speaker builders named for their surnames. Raun was the engineer, and in 2011 he began the design that became the S300, aiming, as Mads tells it, to outperform anything at its price. Buchardt Audio launched in 2013, and Mads recalls a constant line outside its room at the Danish Hifi & Surround show at the Copenhagen Hilton in 2014. Passive radiators go back to the early S200, and the A500 active speaker won a 2020 SoundStage! Network Product of the Year award for Innovation in Design. The Anniversary 10 marked the tenth year in 2023 and was the first Buchardt built in Denmark, in solid wood. Eric van Spelde of Hi-Fi+ notes the brand's following among streaming listeners and amateur music producers, a younger crowd than most high-end stores see. Buchardt now makes many of its cabinets and stands from solid European wood in its own Silkeborg workshop.