The Heil Pro Set 3 stereo headphones feature excellent audio clarity and balanced frequency response, ranging from 10 Hz to 22 kHz. Suitable for a wide variety of applications such as studio recording, broadcasting, and streaming, as well as just an enhanced listening experience. The Pro Set 3 also features a phase reversal switch to run the speakers out of phase. When switched to the OUT position, the polarity will be reversed, providing the listener with different perceived sound positioning in their head.