According to Scandinavian design principles, products should sit in harmony with their environment and be built to last. A noble idea, even if – in a region with some of the world’s highest tax rates – it can make things rather expensive.

Take anything ever made by Bang & Olufsen, for example: you might not immediately realise you’ve remortgaged your house for an iconic TV, but 20 years later when it’s still going and still the centrepiece of your living room, it’ll hit home.

Swedish company Transparent Sound doesn’t deal in the conventional either, offering Bluetooth speakers made from materials like stoneware and glass that push the boundaries of hi-fi design. Its Transparent Speaker is undeniably striking, with flawless build quality and materials made to last a lifetime… which is entirely the point, except that here you’ll also find some modular magic at play to ensure the tech stays up to date.

Design: A glass act

The Transparent Speaker is an undeniably gorgeous creation constructed from a single aluminium uniframe and tempered glass. Apart from the black chassis, black components, and red wiring, it’s completely clear and generally looks the part wherever you place it.

At the size of a small briefcase and weighing 11kg it’s noticeably heavy, so this is one wireless speaker where you’ll want to decide on a spot and stick with it. It also comes with a pair of white gloves for impromptu mime artist sessions and ensuring you don’t get grubby mits on the glass when wall mounting or positioning it in place.

To the bottom left you’ll find a rectangular control module branded ‘Transparent Speaker’ with an on/off switch, separate knobs for volume, bass and treble, and a 3.5mm auxiliary line-in.

On the rear you’ll find another 3.5mm line-in, a 3.5mm line-out and a USB power socket. The speaker comes with two audio leads of different lengths and two power power cables (USB and mains). Elsewhere, red speaker wire leads to the two exposed cones and woofer.

Curiously you’ll also find slightly cryptic wording and an arrow pointing to the wonderfully named ‘Tinker Tool’ – this is where the Transparent Speaker’s modular magic comes into full effect.

Features: Minimalism impact

Transparent Sound want you to really get to know your speaker, so much so it includes instructions on how to disassemble the device. This is more than just a gimmick to get audio nerds salivating, it’s central to the company’s philosophy.

According to another Scandinavian design principle, things should be made to last and so the Transparent Speaker is designed to become better over time by swapping out components if they stop working or new technologies become available – this is a speaker is for life, not just for Christmas.

It also means you have the ability to add plug-in upgrades to your Transparent Speaker, such as an Amazon Alexa Echo Input for voice smarts and multiroom capabilities – although the sharp-minded among you will realise this means they don’t have them in the first place.

Indeed, this is a basic Bluetooth speaker in every sense of the word – no Apple AirPlay 2, no Chromecast, no built-in streaming services, no battery, and there isn’t even an app. Some will find the lack of features baffling for £900, others will thrive on the blank canvas for continually adding the latest connected components.

In practice taking the speaker apart is child’s play and you don’t need to be a certified electrician to get to grips with it. It also gives you another use for those white gloves, plus retrofitting your own features can be pretty empowering.

Performance: Kicks in glass houses

The speaker’s glass cabinet houses a Class D active amplifier and a high quality DSP (digital signal processor) feeding two 3in full range drivers and a 6.5in subwoofer. They’re well spaced out, never appear cluttered, and offer a maximum 100W output. Obviously it’s stereo from the off, so no need to pair multiple speakers.

Glass gets a bad rep from some audiophiles, with some saying it deteriorates sound, plus if vibrations become too large it can break. No such problems here where the Transparent Speaker’s tempered panes remained resolute throughout. In fact, at no stage did sound quality suffer even when placing it on another glass surface, which frankly feels like witchcraft.

Running the speaker in with ‘Ghosteen’ by Nick Cave and the Bad Seeds, the synths, pianos and electronics at play all sound pleasingly warm without becoming overbearing. Switching to the retro-soul of the Free Nationals self-titled debut, frequencies feel like they’re all in the right place and when a little more low end is desired it’s refreshing to instantaneously toggle from front of the device and not wade into endless app sub-menus.

Boom bap beats on Foreign Beggars’ ‘Matriarchy’ is a different story, and on hip hop in general where some of the impact is lost, but that’s arguably a consequence of the clean and natural sound virtually trademarked by Scandaniavian brands.

Transparent Speaker verdict

Simplicity is the Transparent Speaker’s greatest strength and its greatest weakness. There’s something incredibly refreshing about unboxing a new gadget that doesn’t need to be connected to the Wifi, have the firmware updated and a companion app downloaded.

However, the chronic lack of features will grate, and buying a wireless speaker in 2020 that doesn’t come with voice smarts and multiroom capabilities fresh from the box feels crazy – especially with one costing £900.

The speaker itself is striking, with flawless build quality and materials that will last a lifetime, and given Transparent Sound’s deeply admirable modular philosophy that’s entirely the point.

It sounds fantastic, overcoming any lingering acoustic doubts about its glass build with aplomb, and the little attentions to detail from its cute messaging to the bundled white gloves, make using it a real occasion. The test is whether you can go without the connectivity or be bothered to add it yourself.

Half the price: Small Transparent Speaker

At £450, the Small Transparent Speaker is half the price and half the size of its sibling. You lose the subwoofer, swap black components for white and reduce the stereo output to 30W, but as a sensible Bluetooth speaker it actually makes more sense.

Perfectly sized for bedside cabinets, kitchen worktops, wall-mounting or moving around the house, it uses the same aluminium uniframe and tempered glass, and the white components and wires sit smartly in any environment. It carries the same modular options hidden in the base, but with one difference: you can wirelessly connect two Small Transparent Speakers without a multiroom upgrade.

We found it plenty loud enough to fill an open-plan kitchen diner, giving the Apple HomePod a run for its money in the sound stakes, while the lack of on-speaker controls is easily remedied with your phone’s EQ. And yes, you still get the white gloves.