Hi, I bought a Focusrite Scarlett 2i2 (2nd Gen) to use with REW and my Macbook Pro (El Capitan) for measuring my loudspeakers. When doing a soundcard calibration the frequency response is somewhat curtailed (-3dB at 18kHz). Exactly the same result was obtained when measuring the response of my amplifier using the Scarlett. Although the cal is not required as I am using a UMIK-1, this will surely compromise HF when performing loudspeaker measurements. Any idea where I am going wrong?