The IMR Acoustics R1 Zenith is an excellent pair of IEMs that can be used by both bass heads and audio purists alike due to its excellent implementation of the tuning filters and I highly recommend buying these IEMs if you have the dosh to spare for them.
With an outstanding build quality, the RHA T20i is made to last. It even comes with a tuning filter system to change the sound signature with ease. But I wouldn't recommend it to hardcore audiophiles