Based on my experience, the only hard thing to do where they make Dynaudio speakers is to listen to the speakers. I spent a day there earlier this year and was shown where they make drivers, where they make cabinets and where the two come together to make speakers. I wandered through the spectacular R&D centre, had lunch in the cafeteria and sat inside a couple of meeting rooms, but when it came to listening to the speakers, things just fell apart.

I promised to get back to you after I'd had a proper audition of the company's latest creation, the Special Forty bookshelf developed to mark Dynaudio's 40th birthday. I've had a pair in the man cave for a week now.

New speakers need running in. The moving parts – the motor driving the cone, the spider and roll surround providing the cone with its suspension and the cone itself – are all pretty tight and need to be loosened up before passing judgment. Run-in times vary but are usually a couple of weeks of daily use. This can be shortened by playing them loud but it risks permanent damage. Smooth and steady is best.

This pair came fresh off the boat from Denmark and had to be delivered to a local dealer for a launch after my turn. He was relying on me for the run-in, so I ran them pretty much 24/7. And while I was listening to them constantly (when I was awake anyway), I had a detailed listen on the day I unpacked them and on the day before I handed them over.

Out of the box I noted: "Wonderfully decisive bass with brilliant decay, and beautifully defined high range." The start of Aaron Copland's Fanfare for the Common Man is not unlike listening to someone belting an empty corrugated iron water tank with a star picket, and what got me was the way that sound decayed, shuddering away to nothing, the horns managing to hang in amid the clatter. Very even-handed sound.

And Philip Glass' Anthem from the Powaqqatsi soundtrack, with its strong, lurking bass line at the bottom end and its brooding flutes up top was a complete and beautifully delivered item, no weaknesses anywhere.

But John Williams' Olympic Fanfare – the theme music of the 1984 Games – was a different matter entirely. It's very detailed with lots of rapid fire trumpet and heaps of sharp, fast boom-tish. A week of solid running-in took it from exciting to inspiring.

John Tavener's Protecting Veil has deep, skulking bass interspersed with highs that are abrupt and sharp as broken glass, it's a challenging piece for musicians and for hi-fi equipment. A week on the Special Forties walked through it and added such intense detail and airiness that I played it twice. Very loud.

The midrange had become beautifully definite and especially good with voice, great for television and movies, but the bottom end was the biggest beneficiary, getting roomier and luscious without losing its definition. Or decay. These are exhilarating speakers that get you involved and start you on a journey of rediscovering your music. A week is not nearly enough.

The Special Forties are compact for their sound (20 centimetres wide, 36 centimetres high, 31 centimetres deep) and among the best finished bookshelves you'll find. A pair costs $4499. Everyone has different ears and different musical preferences and no one's going to spend this much without doing some serious listening around first, but to use Molly's words, do yourself a favour and make sure you include these in the mix.