The Hi-Fi Plus with B&O Play aims to bring lush Bang & Olufsen (B&O) sound quality to LG's G5 modular smartphone and other compatible handsets.
It does this by incorporating hi-fi DAC (digital-to-analogue converter) technology. This converts digital data into an analogue signal so we can hear it.
Most smartphones (including the G5) have a built-in DAC. But standalone versions, such as the Hi-Fi Plus, can perform higher quality conversions for better sound quality.
But does it warrant a listen? Turn on, tune in, and rock out as we take it for a spin in our review.
First impressions and design
The Hi-Fi Plus isn't up there with B&O's best looking stereo equipment. But then seeing as it's hidden away and slots into the bottom of your phone, it doesn't have to be.
The rubber finish feels suitably premium, and it's simple – if a little stubborn – to pull out and plug in.
Like other add-ons in LG G5's range of Friends set up is easy. Simply remove the phone's base and take out the battery. Then slot the battery into the B&O Play unit and attach it to the phone.
Switch it on and plug in a pair of headphones and a logo appears in the notifications bar. You're now up and running.
It might look like just a black rectangle, but the B&O Play features some serious audio engineering.
The G5 actually has its own DAC technology built-in, but the Hi-Fi Plus with B&O Play overrides it.
That's very welcome, as B&O's tech is a lot more capable.
Songs sound much crisper, and there's a much wider soundscape encompassing a broader range of sounds.
Pipe through some songs stored as hi-res audio files (either by streaming them online or playing those stashed away on your phone), plug in a pair of decent headphones, and you'll really notice the difference.
The Play comes with a plush leather carry pouch, which is a nice touch. And there's a top section that contains a USB Type-C port.
Detach the Play from the phone, connect its two halves, and you can hook it up to a laptop or tablet using USB. So better sound quality isn't confined to your phone.
Downsides? It won't play a clip that you started before you plugged the headphones in, which is annoying.
The speaker grille is also easy to block with your hand when you're holding it, which muffles the sound.
It also didn't polish the sound from our tablet quite as much as it did that from the G5.
At £150, the B&o Play certainly isn't cheap. And if you're not fussed about sound quality, it's not the accessory for you. But those who are serious about sound will the Hi-Fi Plus with B&O Play.