Sennheiser CX 980

Design

As you can see, the two headphones have slightly different designs. The QC15s are over-ear headphones with an active noise cancellation feature that requires a single AAA battery. The CX 980s are a set of in-ears with no fancy-pants cancellation, and, as in-ears, are significantly more fragile than the QC15s.

Sennheiser CX 980	Bose QuietComfort 15

Frequency Response

The CX 980s have a much more even keel to their frequency response.

Sennheiser CX 980	Bose QuietComfort 15

Distortion

The QC15s have a bit more distortion than the CX 980s; when the QC15s’ active cancellation feature is enabled, the headphones suffer from a great deal of distortion.

Sennheiser CX 980	Bose QuietComfort 15

Tracking

The QC15s have a bit of volume wobble between the left and right channels towards the high end of the frequency spectrum.

Sennheiser CX 980	Bose QuietComfort 15

Isolation

The CX 980s don’t block out as much noise as the QC15s, especially when the latter has its active cancellation feature switched on.

Sennheiser CX 980	Bose QuietComfort 15

Comfort

The Bose QC15s are significantly more comfortable than the CX 980s in that they don’t seek to cram their entirety into your head.

Wear
Sennheiser CX 980	Bose QuietComfort 15

Verdict

The CX 980s are definitely the better set of headphones if you’re looking for audio quality or portability, but if you’re looking to take your headphones anywhere noisy, the choice is less clear. Audio quality doesn’t count for much when there’s external noise competing with your playback. If you find yourself mainly listening to music in obnoxiously loud locations, or you simply don’t like shoving stuff in your ears, you should consider the QC15s.