DALI IO-4 Headphones Review

Posted on 20th October, 2019

DALI IO-4 Headphones Review

DALI launched its first-ever headphones at IFA 2019, Berlin last month. Of course, we were there and came back to HQ wearing a set of the new DALI iO-4 to review.





Danish Audiophile Loudspeaker Industries, better known as DALI, has brought its hi-fi speaker know-how to portable ear-pleasers.


Launched at IFA 2019, the Danes unveiled the Dali iO-4 and Dali iO-6 headphones. The latter boasts noise cancelling as an extra skill.

DALI is no stranger to wireless audio. However, the Danish company has noticed how popular Bluetooth headphones are. Moreover, the brand has obviously been waiting for Bluetooth audio to match its sound quality expectations.  

DALI iO-4 Design

Chatting with them at their stand at IFA, we could not help but admire the company's approach to creating these new cans. Basically, they have taken their hi-fi loudspeakers and miniaturised the drivers to fit over your ears.

The 50mm drivers are custom made and are fitted with paper/fibre cones, typical in loudspeakers.

DALI iO-4 headphones

Furthermore, the over-ear enclosures are braced and stiff, just like speaker cabinets. Finally, rubber dampeners inside eliminate unwanted vibrations.


The iO headphones sport Bluetooth 5.0 and support aptX, aptX HD and AAC to maximise the wireless music quality.

On the left side you have the 3.5mm jack just in case you run out of juice.

DALI iO-4 headphone review

Over on the right cup, as well as the power on/off/pairing switch and indicator LEDs, you also have remote controls for volume and track pause/play, rewind and forwarding. Those controls are acheived by tapping the central silver part of the cup-face a number of times depending what you are wanting to do.

DALI iO-4 headphone review

Finally, there is a USB-C port for charging as well as playback.


On the subject of charging, the iO-4 headphones have a noteworthy 60 hours of battery life. You can half that for the noise-cancelling iO-6 but, still, 30 hours is remarkable. A full recharge only takes two hours.


DALI iO-4 headphones

We have been wearing the iO-4 consistently for the past few weeks. The DALI headphones have been durable and cope well with being shoved in our bag. 

Additionally, as well as being resilient, they are also comfortable. 

DALI iO-4 Headphones

The headband and memory foam earpads are nicely padded; both are covered in synthetic leather. 

The headband is pretty flexible, and there is a decent amount of clamping pressure keeping the headphones in situ. Finally, the headphones are also extremely light, too.

Another nice touch is, just like speaker grilles, the earpads can easily be removed for cleaning.

DALI iO-4 Headphones

Finally, the iO-4 are IP53 certified, and the ear cups rotate 90 degrees both ways to fold flat for compact storage or to hang comfortably around your neck.

Sound quality

The DALI iO-4 presents a flat-response which is our preference. We prefer our headphones to be honest without any frequency-boosting shenanigans. If you're looking for 'phat beats' as they said back in the day, head elsewhere. 

DALI iO-4 headphones

We think this is a refreshing stance and stays true to the Danish audiophile's sound signature. Because of that stance, these headphones play the music as it was intended to be heard.

That faithfulness remains no matter what genre of tune you throw at them and enables you to hear the full spectrum of the sound exactly as it was dialled in by the studio engineer.

Don't mistake all that to mean the iO-4 are bass-light, far from it. Instead, the bass is reproduced accurately and naturally.

TOOL's latest opus, Fear Inoculum, had just been unleashed and has had plenty of playing time since. The album is well-produced, and the DALI iO-4 presented plenty of detail and expression from the technical alternative metallers.

Ned's Atomic Dustbin and their typical twin bass indie assault throughout Godfodder sounded fantastic. The two bassists weaving catchy low-end lines never muddied the midrange, or get in the way of the vocals, drums or guitar.

Some headphones and earphones can be a bit bitey in the upper frequencies to add clarity or accuracy. Thankfully, the DALI's are more laid-back but, without losing precision. Additionally, this lends the iO-4 to being more acceptable on long listening sessions. Those more shimmery headsets can be a tad fatiguing.

The typically 80s production of Def Leppard's Hysteria has all the pomp, strutting and posturing that made us fans of rock and metal in the first place. Listening to the Super Deluxe version on Tidal, the cymbals and guitars cut through without being harsh. Even Elliot's higher vocals/screams don't grate. 

Finally, Dido's latest album is like audio silk. Her semi-spoken song style is relaxed, but the DALI iO-4 still presents her backing faithfully and accurately.

All-in-all the DALI headphones impress without the need to be boastful. There is a certain poise and elegance to their performance.


For its first toe-dip into the headphone market, DALI has produced an impressive pair of headphones.

Perhaps not aimed so much at the high N-R-G workout types, the DALI iO-4 instead focus on DALI's hi-fi demographic. So, if you value a more honest reproduction of the music you love, then these headphones will suit.

Fit and finish are great and we love the clean Danish styling. 

The on-ear control took a little bit of getting used to finding us mostly controlling playback from our phone.

Bluetooth aptX HD does a great job keeping the quality up there, and we didn't suffer any drop-outs, even in the killing fields of Liverpool Street and Kings Cross stations during rush hour.

The DALI iO-4 is currently our go-to full-size Bluetooth headphones and because of that, surely deserve our Applause Award.

Finally, if you are a frequent flyer, we reckon you should check out the iO-4's active noise cancelling siblings, the iO-6.

Price and availability

Both the iO-4 and iO-6 are available in Iron Black and Caramel White priced at £269 and £349 respectively. 

For more information, go to DALI.


      Jay Garrett's avatar

      Jay Garrett

      StereoNET UK’s Editor, bass player, and resident rock star! Jay’s passion for gadgets and Hi-Fi is second only to being a touring musician.

      Posted in:Headphones Applause Awards 2019 Headphones Over / On Ear Bluetooth / Wireless
      Tags: dali  applause award  ifa2019 


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