Professional singers and musicians looking for a high-quality in-ear monitors should check out the Westone Pro X30, a pair of universal-fit in-ear monitors for onstage monitoring by vocalists, guitar players, keyboard players, drummers, and sound engineers. The Pro X30 ear monitors deliver both comfort and proper in-ear coupling, increasing sonic detail and clarity. The soundstage features powerful lows, articulate mids, and crystal-clear highs that produce performance, power, and output that's great for any stage or venue. The earphones employ three of Westone’s balanced-armature drivers with a 3-way passive crossover to deliver a frequency response of 20 Hz to 18 kHz at a sensitivity of 124 dB SPL.