The Dali IO-4 delivers the most unique sound I’ve ever heard on a wireless headphone. Remarkably precise and clean, the IO presents a very nuanced sound signature. And anyone who enjoys an acoustic track will undoubtedly be impressed with how natural the sound feels. Furthermore, for those who like a lightweight sound profile, it doesn’t get any lighter (or thinner) than this. But that’s also the problem with the IO-4. It’s not necessarily a crowd pleaser, given that most crowds go for a richer and warmer feel with a lot more bass. And the bass is certainly lacking. That being said, my colleagues who tried the noise-cancelling IO-6 did mention that it offered plenty of warmth and sufficient bass. So, if you don’t mind spending the extra 100 bucks on the IO-6, you can get the best of all worlds.

The Dali IO-4 offers the same convincing sound quality as the larger model the IO-6. And they are equally comfortable to wear and straightforward to use. The only real difference is the lack of active noise cancelling, which saves the buyer one hundred euros; for this sacrifice, you get a battery life which is twice as long. At a price of 299 euros, we really recommend the IO-4 for sound-conscious music lovers.

This is a beautiful pair of elegant, long-lasting and capable headphones, but the performance errs on the side of caution

The only things I could find to complain about when I reviewed the IO-6 headphones were the so-so noise canceling and the fussy reverse track skip function—but with the IO-4s, the former is not applicable and the latter doesn’t seem to be a problem. Really, the only thing I can complain about is that the price is pretty high for a set of Bluetooth headphones without noise canceling, but the IO-4s easily rank among the best-sounding Bluetooth headphones I’ve tried. So if you’re looking for non-noise-canceling Bluetooth headphones—say, for the home or office, where noise canceling does little good anyway—these are well worth checking out.