Isomike system Falling in love a heart-shaped mike Some of the best sound Andrew Everard has heard is the result of an American audio manufacturer's personal passion

The best sound at the Home Entertainment 2003 show wasn't one of those huge arrays of massive US high end electronics with even more massive price-tags. The room I enjoyed the most was actually one discovered almost by accident.

It was under the banner of DiAural, a company started by Kimber Kahle employee Eric Alexander and co-owned by Ray Kimber himself, and based, like the cable company, in Ogden, Utah. DiAural designs and licenses novel crossover technology, using a greatly simplified component layout for a more direct communication of the music. But what caught my attention wasn't the speakers being used, impressive though they were, but the recordings being played, the results of another Ray Kimber project - IsoMike.

IsoMike uses widely-spaced omnidirectional microphones separated by a baffle to record in stereo. There's nothing revolutionary there, but the baffle used is rather different to those employed elsewhere: it's shaped like a stylised heart turned on its side, is very large indeed, and is made from highly absorptive material, shaped to improve low frequency isolation of the microphones. Two smaller heart shaped baffles behind the array control the amount of reflected sound from the rear of the auditorium reaching the microphones.

Many different microphones have been tested using this system, including models from AKG, Neumann, Senuheiser and others, and running several identical recorders in parallel allowed up to four pairs of microphones to be used simultaneously and their results compared. The recorders used were Tascam's DSD98HRs, which create Direct Stream Digital digital tapes, employing the enabling technology for Super Audio CD, and the results were then edited, without any gain changes or processing, on a Pyramix Digital Workstation. The recordings being played from the show were straight off the master tapes.

And what recordings! The experiments with IsoMike were carried out at Weber State University, also in Kimber

Kable's hometown of Ogden, and involved music played by students, teachers and guests. What was striking about them was the enthusiasm of the performers, and the direct, intimate sense of presence. We spent a long time listening in the room, and seeing Kimber hand a little 'white label' package of CDs downsampled from the tapes to some visitors, I asked if could have a copy to take another listen when I got home.

To my surprise, Kiinber gave me not only a pair of CDs but also a copy of the master tape on digital cassette, pointing out that I'd need to get hold of one of the Tascam machines to play it. A couple of weeks later, thanks to TEAC's PR adviser Andy Giles and his clients - who were a little surprised that a consumer magazine wanted to borrow a £6000 pro recorder - the DS-D98HR was hooked into my system, and the tape was ready to be played.

While the CDs are remarkable in their own right, with that sense of clarity, presence and dynamics surviving intact, the impact of the DSD tape can't be underestimated. This really is like being in the auditorium while the performance was given. The dynamics of the recordings are completely amazing: from solo percussion to choral and orchestral recordings, the ability of these tapes to induce a shiver is matched only by the hard-disc master recordings I heard played by Tony Faulkner at the Bristol Sound & Vision show earlier in the year.

Voices just hang in the room, and the impression of walls disappearing to be replaced by a concert-hall platform extending Out beyond the back wall is magical. Some, I know, will find this kind of recording, red in tooth and claw, a little too real -those used to more limited dynamic range, and a slightly smoother presentation, will need to adjust to what they're hearing. However, these are some of the most exciting reproductions of live music I have ever heard, and certainly get closer to reality than just about any commercial release I can recall. I look forward to hearing more from the IsoMike system in the future, and I'm pretty confident that we will. ( Copies of the IsoMike CDs can be bought from the company in return for a donation of your choice to Weber State University, where the recordings were made. The IsoMike website at www.kimber.com/isomike.htm has ordering information.