I was once lucky enough to go to Sweden to make a TV show about tractor pulling. Blokes go along, eat smoked eels, get drunk with true determination, then hoot and holler while mad tractors fling mud around, and some announcer shouts: 'Fuuuull Puuuull!'

And this is because the Swedes truly adore their fine engineering for its own sake, as well as what it can do, whether it's six V8 engines strapped onto one shaft for the Lego-sponsored tractor pullers, or a Volvo that just simply starts first time at 20˚C below zero!

There is a fine core of speaker excellence coming out of Sweden, too, with real knowledge in the labour pool. The XTZ brand we see here is gorgeously built, and the drivers are all by SEAS (Scandinavian Electro Acoustic Systems), a Norwegian company that's been in the driver business since 1925, so it knows a thing or two.

A relatively new company, XTZ (distributed in the UK by Audio Sanctum) has drawn expertise of all sorts from making to selling, across the whole industry. And while in Europe the company specialises in selling direct, in the UK you can get delivery-cost-only free demos in your own home to effectively offer the same service as mainland Europe, but without the delays and costs of UK shipping times from there.

Sonic smorgasbord

What XTZ has done is to take the poshest SEAS drivers, enclose them in shapely Piano Black cabinets, and then with a terribly Scandinavian relaxed attitude, engineered them to be as close as possible to having universal appeal. Not for XTZ are the rules of placement and execution cast in stone.

On the contrary, each product in this 99 series is highly adjustable, starting with the plug holes. All speakers, for lower tones, need air space to bump against, a volume of breeze to use as 'acoustic suspension'. In fact, the 'Thiele/Small' parameter for the bounciness of a transducer cone's suspension assembly as a whole is known as the Vas – or equivalent volume of air to be as 'bouncy' as the driver.

They also tend to have (like a ruler held on a desk's edge and twanged), a resonant wobbly frequency they 'like' best. Using all these parameters, a clever speaker designer can port an enclosure get a big advantage.

You will have a 'tuned' frequency around which this port advantage accrues, and while the bass can be 3dB louder, at this point it'll drop away quickly below the tuned frequency. If you seal up a bass enclosure, the bass won't be as loud, but will drop as low as the driver's wobbliness allows, often deeper by far than a ported box can reach.

Deciding how and by what centre frequency to tune a bass-end enclosure can be very difficult. But what if you had lots of different sized ports, with foam bungs you can shove up them?

Then it gets really clever. This system's 99W12.16 subwoofer has two ports of different lengths. With two fat foam bungs you can stopper up both, either or neither hole, to offer up four different 'tunings', as described admirably in the well-written and only slightly Swedish/English manuals (which refers to the term 'Pondus' as a unit of weight…)

XTZ 99 series

I plugged up just one port to offer the deepest tuning and then investigated the neat 99.25 bookshelf speaker. I had three.

At first I thought the centre was identical but with the badge put on sideways, but, crucially, the fabulous leaf tweeter has also been swivelled vertically, to match those on the surrounds. There are superior aluminium phase-plug-equipped 6.5-inch SEAS 'Excel' midbass drivers in each of the five enclosures.

The surrounds offer dual binding posts, joined until you choose to bi-wire or bi-amp, while the 99.36 towers have a triple still-joined set to offer up tri-wiring/tri-amping for their extra, deeper bass driver (also 6.5-inch but without a phase plug and far wobblier). They are fashioned from classic non-pressed paper, rather than the fabulous magnesium from which the mids are fabricated.

Unbunged and set to go

There are more ports to play with here: one on the 25s and three behind the 36s. You can again choose how to tune and play to your heart's content with foam bungs.

Likewise, each has two jumpers on the back (or four on the big ones) used to adjust tweeter or woofer levels. These are exactly like high-end car component systems where the passive crossovers have resistors you can place in and out of circuit. This makes complete nonsense of the +3dB setting, as these resistors can only offer variable attenuation, or different amounts of 'cut' of levels.

I set all to maximum, non-resisted and chose to run the all ports unbunged. During my audition I played some multichannel material from Linkin Park (a 5.1 DTS track on an ill-fated, but still worth snapping up DVD-A disc) and spun up The Polar Express on DVD.

The Park damn well rocked, and when the eponymous train arrives in Zemeckis' movie, the room was not only filled with hugeness, but also with plenty of well-placed steam train detail. And the preceding part, with its challenging and tweaky sections (a metal hubcap in the kid's room being hit; a steaming radiator...) was just superb in so many ways, from deep, throbbing, well-held bass to tinkling, delicate, detailed highs.

XTZ 99 series

For the money, this system really represents astonishing high-end value – don't let the direct sale nature put you off an audition. Yes, the styling isn't going to win any awards, but the tunability and sound quality is excellent.

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