Im a bit confused when it comes to the "check level" part. The guide says
Can someone explain what I should change and look at to get the -18db ?The input level should be around -18dB FS when the cal signal is playing, if it is lower or higher adjust the Input Volume either using the REW control (if enabled) or your soundcard's mixer or OS audio level controls. The target range is -24dB to -12dB FS. Levels higher than -12dB may result in input clipping during measurement, levels lower than -24dB give noisier results.