H20 Audio Sonar 2 Pro Review

Price

The H20 Audio Sonar 2 Pro was officially announced and launched in September 2025, with a launch price of £136 / $149.99. That makes them more expensive than the first generation Sonar (£96).

Despite that increase, it does stay in line with the price of other swimming headphones. The Shokz OpenSwim Pro costs £169, with the Shokz OpenSwim sitting at £139.

The solid-performing Nank Runner Diver2 Pro is another alternative and costs £148.54, while the Suunto Aqua is a pricey buy at £175. If you want to spend less, the Jabees 7Seven includes both music player and Bluetooth streaming for £61.

Design

• Revamped design
• More physical controls added
• IPX8 waterproof rating

The Sonar 2 Pro certainly bucks the design trend typically associated with swimming headphones. I’d call it a bit like wearing two flattened USB thumb drives attached to a flexible blue cable. They’re specifically designed to be worn when clipped to the strap of a pair of swimming goggles. That rules them out being all that useful out of the water.

H20 Audio has focused on making the Sonar 2 Pro lighter and slimmer than the previous Sonar. It’s also added more physical buttons. Interestingly, there’s now a fully waterproof microphone should you want to take a call mid-swim.

These aren’t headphones I’d say you can effortlessly slip on. Clipping them onto a goggle strap takes a bit of fiddling and often led me to leave them clipped on after swims to avoid going through that process again.

It’s always pleasing to see physical buttons on sports headphones, and there’s a good set on the Sonar 2 Pro. There’s dedicated buttons to switch between listening modes, adjust volume and to skip back and forward through audio. While buttons are packed quite closely together, you can feel for the raised surfaces on them to make it easier to distinguish between them.

The level of waterproofing remains as strong as the first Sonar. These are IPX8 rated, which means they can be submerged in water up to 3.6 metres deep (12 feet) for an unlimited amount of time.

In the box, you’ll also find earplugs to improve sound isolation in the water, alongside the proprietary charging and data syncing cable. There is a compact case to keep everything all together in one place.

If you’re interested in the prospect of streaming audio over Bluetooth from an Apple Watch (Ultra or Series), you can pay for the optional Apple Watch clip, which will cost you £20 / $24.99.

Features

• 8GB music player
• Optional clip for smartwatch Bluetooth streaming
• PlayList+ feature for adding audio via app
• Better battery life than first generation Sonar

Streaming audio is done over Bluetooth or the onboard 8GB music player. The latter gives you 130 hours (or 2,000 songs) to play with. There’s support for MP3, M4A, WMA and APE file formats.

You have two ways to get that audio on. You can either connect the headphones to a computer using the supplied cable to drag and drop files on. Alternatively, you can use the H20 Audio smartphone app (iOS and Android) and turn to the somewhat archaic PlayList+ feature.

This lets you record audio through the app and headphones over Bluetooth. A bit like you would if you remember using cassette tapes to record music off the radio. I’ve tried this on other H20 Audio headphones and while it does work, it’s an interesting workaround to try to increase your audio options. It just requires you really to leave your phone to stream audio for anywhere from 30 minutes to 4-5 hours.

There is another route to audio and that’s by streaming over Bluetooth. Most swimming headphones opt against this as maintaining a reliable Bluetooth connection in the water is challenging. H20 Audio seeks to solve this through a clip that’s compatible with the Apple Watch and lets you move Apple’s smartwatch from your wrist up to your head.

Like the headphones, it needs to be clipped to the swimming goggle strap. This shortens the distance of the Bluetooth connection between headphone and smartwatch to prevent connection drop outs.

H20 Audio says the Sonar 2 Pro can do this with any smartwatch, but currently only offers a clip optimised for the Apple Watch.

Adding that clip into the setup process makes an already awkward one even more awkward. It certainly tested my patience trying to get it in place while also getting ready for a swim. I did eventually get used to having the clip and watch sat behind my head, but I would definitely prefer a much more streamlined setup when wearing the clip and headphones at the same time.

The streaming itself did work better than I expected. I stored some offline music from Apple Music and Spotify onto my Apple Watch Ultra 3 and an Apple Watch Series 11 and it did work as promised. I wouldn’t say it was entirely free of some drop outs, which mainly happened when I turned to complete another lap.

They didn’t seem to love it during  breaststroke sections of swims, where my head was dipping in and out of the water. Connectivity was more reliable when keeping your head in the water.

The battery performance has been fine on the whole. As to be expected, this can vary depending on the streaming method. You can get up to 9 hours of battery when streaming over Bluetooth or six hours streaming from the music player. Those numbers largely represent my time with them.

Streaming from the music player, especially at louder volumes, does dent the battery quicker. You also have to deal with a proprietary charging cable to power them up again, adding another cable to your life you could probably do without.

Sound Quality

• Uses bone conduction technology

The Sonar 2 Pro delivers sound through bone conduction technology. It’s now a newer version of that technology featured on the first Sonar.

In terms of performance, I’d describe the sound quality as perfectly acceptable for swims. Is it the best sound I’ve experienced from a set of swimming headphones? No. It doesn’t quite match the balance, power and clarity you’ll find from the likes of the Shokz OpenSwim Pro. Overall, I was happy with what they could muster up in the water.

There’s some familiar bone conduction hallmarks to contend with however. If you’re listening at louder volumes, you will notice a bit of bone conduction vibration tickle. They’ll also leak audio in a noticeable way too.

On Caribou’s Can’t Do Without You, bass is punchy with a mids performance that’s battling to be smoother than how things actually play out. On the Eagles’ Hotel California, there’s some pleasing warmth, with trebles on the grainy side. It’s a very good match for listening to podcasts and audiobooks. It might not offer the crispest, clearest sound, but there’s more than enough in that performance when you need to swap music for voices.

Should you buy it?