Adidas Sennheiser CX680i Review

Reviewing audio equipment such as headphones/IEMs is often a tough task; audio quality is often quite subjective — different people have different preferences and expectations as to how their audio equipment should behave.   Having said that, Sennheiser’s audio products are known to be pretty good and I was thrilled to receive a review unit of the Sennheiser CX680i. Let’s see how it plays.

Box Contents, Design &  Look And Feel

Along with the earphones, the box pack comes with a shirt clip, a cleaning tool, few extra tips and an Adidas branded carrying case.

The Sennheiser CX680i at first glance looks like pretty much standard IEM. However, the CX680i’s funky color is the first thing that’s going to grab most people’s attention. Personally, I found the near-florescent yellow color a bit jarring and flashy for my taste. Having said that, it does grab attention and I was asked by few of my colleagues for more details on the IEM. You don’t see that happening often!

Color issues aside, the CX680i is tagged as a sports-optimized design and there’s a neat little fin which helps the IEM hit snugly in-between your earlobes, preventing the IEMs from falling down while jogging.

Earphone pictures courtesy Sennheiser’s product page


The CX680i also acts as a headset, with an inbuilt-microphone and remote control jack for adjusting volume/activating voice controls/picking up calls. Unfortunately, this seems to be optimized only across iOS devices – for neither the control for accepting calls not the buttons for adjusting volumes/changing tracks worked with my Android-based Samsung Galaxy S II.  A shame this, having it work universally across devices is what Sennheiser should have aimed to do, rather than limit it to iOS devices.

Audio Quality & Performance

While I’m no audiophile, I do like investing on a  quality set of earphones, since I listen to music quite a lot. With this in mind, I had to judge the Sennheiser CX680i against my current earphones – the Denon AH-C360 and the Klipsch S4a.

When compared to the Denon & the Klipsch, the Sennheiser CX680i performed admirably well. The CX680i didn’t have the same level of thumping bass that the Denon had, but nonetheless was well pronounced and could be felt well. On the mids and highs side, the CX680i was not too harsh, well balanced and was quite pleasant to listen to. Pumping up the volumes to high levels didn’t introduce distortions and when plugged into a Fiio E5 earphone amplifier, the CX680i responded well, especially with the bass response. Overall, the 680i responded well to sounds across the spectrum, making your gym workout a pleasure to listen to. The fins on the earphone tips did well enough to prevent the earphones from falling out during mild jogging and the passive noise isolation worked very well —  so much so that I often wouldn’t realize I had people calling me out despite them standing right in front of me.

Pricing & Conclusion

With a retail price of about $100, the CX 680i isn’t exactly inexpensive. But with features such as sweat and water resistance and a Kevlar reinforced cable, the CX 680i is ideal if you listen to a lot of music and have an extensive workout set that keeps destroying your earphones.

Product page – Sennheiser CX 680i