Fitness earbuds that lack finesse

Sennheiser could have just trotted out a set of wireless earbuds that were rated IP55 and called it the Momentum Sport ($330), but it went further, adding heart-rate and body-temperature sensors to the made-for-exercise earbuds. These additions give you more insight into workouts, but also feed data to your existing third-party activity apps. Of course, the Momentum Sport also has to excel at the normal earbud stuff, and offer an ergonomic design, active noise cancellation (ANC), touch controls and other common features. Sennheiser has a solid track record with sound quality, but now it has to balance that with the expanded capabilities of the Momentum Sport.

What’s good about the Sennheiser Momentum Sport

The Momentum Sport’s overall shape is what I wish Sennheiser used for the Momentum True Wireless 4. The former’s rounder profile fits my ears better and feels more comfortable even though they’re slightly larger. Without the fit wing, the Sport version still rests nicely in my ears, though that extra part definitely helps keep them in place during workouts. Simply put, this design feels more refined and I’d love to see the company take a similar direction on its flagship model.

Sennheiser says it aimed for “vivid sound and impressive bass” that would help amp up a workout and it delivered. The stock tuning has noticeably more low-end thump on Justice’s Hyperdrama, bracing the electronic tunes with a thicker layer of tone. That’s definitely something that assists with your energy levels during physical activity. But, as I’ll discuss later, the extra bass isn’t always a good thing.

The Momentum Sport’s marquee features, which are heart-rate and body-temperature tracking, work well. Thanks to the earbuds’ secure fit, you can get constant, dependable readings in Sennheiser’s Smart Control app. Heart rate figures matched those on my Apple Watch, and I confirmed my temperatures with a forehead scan. The Momentum Sport’s readings were consistent with the other devices every time, which means the earbuds are as reliable as other at-home alternatives.

What’s more, there’s tight integration with apps like Polar, Peloton, Strava and Zwift, so you can use the Momentum Sport with their devices and not just Sennheier’s app, which is mostly designed to tweak settings. However, only Polar’s Flow supports the Momentum Sport’s body-temperature tracking. Sennheiser says this is because Polar is the only company with an ecosystem that keeps tabs on that metric and supports the appropriate sensors. No matter which third-party app you prefer, you’ll probably want to sync the Momentum Sport to one of them, since the Smart Control software only displays real-time readings and won’t keep tabs on trends or monitor stats during workouts.

Although it has to power more sensors, the Momentum Sport still delivers solid battery life. Sennheiser says a single charge offers five and a half hours of playback, and that claim holds up. I didn’t have any issues hitting that figure during my testing of looping audio at about 65-70 percent volume. That’s with ANC on normal mode and heart-rate and body temperature sensors active. The company says you can extend the battery on the Momentum Sport by 30 minutes if you enable Eco Mode in its app. This feature disables aptX audio and both of the body-tracking sensors.

What’s not so good on the Momentum Sport

The Momentum Sport lets you tap your cheek for playback and call controls. This is convenient when running, for example, since you don’t have to find the exact location of the touch panel while on the move or if you’re wearing gloves. The downside is that it can be activated by chewing. It is intensely annoying. During my tests, chewing gum or food frequently triggered the controls.

Sennheiser says this is because I have strong jaw muscles (yay?) in close proximity to the sensor, but that doesn’t make it any less maddening. I chew gum during both runs and lifting sessions, so this is a dealbreaker. Just clenching my jaw didn’t trigger it, so at least there’s that. The only way to remedy the issue is to turn off the onboard controls entirely, which disables both the cheek tapping and more common earbud tapping gestures.

The Momentum True Wireless 4’s ANC performance is solid but not amazing and that holds true on the Momentum Sport. Both sets of earbuds perform similarly with constant noise sources, lowering the volume of the external roar rather than blocking it completely. Like a lot of the competition (and the True Wireless 4), the Momentum Sport struggles with human voices. Overall, neither of them offer the kind of robust, world-silencing power that Bose and Sony muster.

Transparency mode on the Momentum Sport is serviceable, but it’s far from great. The earbuds let in your surroundings well, but don’t pipe in enough of your voice and I found myself getting shouty during a few calls. There’s also an anti-wind mode that comes in handy during outdoor workouts, but it’s a tool nearly all new earbuds are equipped with these days.

Unfortunately, good audio performance isn’t universal on the Momentum Sport. While some albums are detailed and crisp despite the added bass, others are missing punchy highs and a strong mid range. The sound profile compresses things like grungy, distorted guitars and bass lines. Vocals consistently cut through, but the more prominent kick drum in songs like Knocked Loose’s chaotic “Suffocate” relegates guitars to the backseat. In fact, guitars across a range of styles – including alternative, rock and country – lack the depth and detail the Momentum 4 provide. By dialing up the low-end tone, Sennheiser has sacrificed some of the dynamics that usually give its earbuds such great audio. And in a set of earbuds that cost over $300, that’s a shame.

Lastly, let’s discuss the case, which is less sophisticated than Sennheiser’s previous designs. These earbuds cost $330 and the charging case shouldn’t feel this flimsy. The lid closes securely most of the time, but the hinge is just a piece of rubber so the case doesn’t stay open unless you lay it all the way flat. The soft-touch coating feels nice, but compared to the accessories that come with the Momentum line, this case is what I’d expect with a set of earbuds that cost half as much. The good news is, there is wireless charging support and the case is rated IPX4, so it’s not all a loss.

Wrap-up

The Momentum Sport presents a dichotomy. On one hand, they’re excellent workout earbuds that reliably track biometric stats for an inside look at your training regime. On the other, they lack the overall sound quality I’ve come to expect from Sennheiser’s Momentum lineup and the overly sensitive controls are an extreme nuisance. The earbuds could improve with some software fine-tuning, but for now, they’re too expensive to buy just for workouts and don’t even perform consistently enough to be your go-to set.