"The SE310s use a single driver solution, but they also incorporate
Shure’s Tuned BassPort technology, to increases the bass response. This
is something that proved to be an issue with the Shure E4c earphones
that we reviewed about a year ago – although the clarity was superb,
they lacked bass, which sometimes robbed music of some of its drama.
Thankfully the SE310s are a definite improvement on the E4c set, and
there’s a far more balanced sound on offer."