Sennheiser CX 686G Sport In-Ear Headphones Review

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Sennheiser continues to make quality audio convenient and affordable with the CX 686G In-Ear Sports headphones. These exercise buds provide supersecure, interchangeable ear inserts; an inline remote; and solid sound, all for only $69. If you're in need of a music companion for your next training session, the CX 686G will serve you well.


The Sennheiser CX 686G Sports earbuds make a strong statement. The bright neon-green design, accented with light- and dark-gray tones, is for athletes who want a pair of earbuds as sporty as they are. Like the Sennheiser CX 685 Adidas Sports earbuds, the CX 686G have an elongated design, using the curved piece of plastic as the backing of the buds. The top curve slides up and down, acting as the ear wing, and the bottom curve attaches each bud to the cord.

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The ear inserts are dark-gray pieces of squishy silicon that can be removed to change sizes. The cord, however, has been updated to a flatter design, compared to the superthin, round cord on the CX 685 earbuds. 

Another addition is the inline remote, which sits at the intersection of the cords and holds a volume rocker and a multifunction button to pause songs and answer calls. This is a huge improvement over the CX 685, because inline remotes let you control music more easily when you're exercising and can't whip out your smartphone. My pair of CX 686G earbuds were fully compatible with Android devices — the volume rocker won't work on iPhones.

However, the CX 686G's cords tangled just as much as the CX 685's, forcing me to fight with them every time I dug them out of my gym bag. The CX 686G earbuds are water resistant, as are the CX 685. 

Comfort and Fit

The Sennheiser CX 686G Sports earbuds come with three ear-insert size options. The largest size provided me the most secure, full fit. I went from lifting weights to jogging on the treadmill to working out on the elliptical without needing to readjust the earbuds at all.

You can move the slide-to-fit ear wings up and down to apply pressure to the outer part of your ear. Adjusting them is easy, and it adds extra security to the buds so they'll be even less likely to move or fall out.

In comparison, the SMS Audio Street by 50 Wired Sport earbuds have interchangeable ear wings in various sizes. Those are convenient when you first open the box, since you can try on all of them and decide the best fit. However, I did like being able to adjust the slide-to-fit ear wings on the CX 686G at any time.

I also prefer the CX 686G's design to the Shure SE112's wire-over-ear design, which was uncomfortable and made the headphones constantly feel like they were going to fall off my head. 

Audio Quality

In songs like Kanye West's "Love Lockdown," the Sennheiser CX 686G Sports earbuds shined with bone-chilling bass. The entire track sounded powerful, as if I were hearing it from inside my brain.

I had a similar experience when listening on the Shure SE112 Sound Isolating headphones but with slightly better bass than the CX 685's. As with other bass-heavy songs, this track also sounded great on SMS Audio's Street by 50 Wired In-Ear Sport headphones, but the CX 686G played the track with the loudest and richest sound.

The theme continued on other genres. The CX 686G earbuds played Twenty One Pilots' "Tear in My Heart" with the depth it deserves, with resonating lows and cherry highs. The CX 685 earbuds favored crisp highs, rich mids and slightly demure bass to make the song sound lighter, while the Shure's sound was balanced but softer. The SMS Audio headphones played a booming track with strong bass but quickly became harsh at its loudest points.

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While the SMS Audio buds are the loudest of the bunch, I much prefer the balanced sound of the CX 686G. 

Bottom Line

The Sennheiser CX 686G Sport earbuds have everything a good pair of exercise buds need: good audio quality with thumping bass, a sporty design with a steady in-ear fit and a convenient inline remote.

You could spend even less and get the $39 Sennheiser CX 685 Adidas Sport earbuds and get similar sound quality. However, you'll sacrifice that crucial inline remote that makes it much easier to control your music while running, sprinting or jogging. Overall, the CX 686G Sport buds are a great pair of headphones that can follow you in and out of the gym.

Valentina Palladino

Valentina is Commerce Editor at Engadget and has covered consumer electronics for a number of publications including Tom's Guide, Wired, Laptop Mag and Ars Technica, with a particular focus on wearables, PCs and other mobile tech.