Check Levels generates a subwoofer or speaker calibration signal at the Sweep Level (the level at which REW generates its measurement sweep, -12 dBFS by default). The replay volume controls, AV processor volume and (if necessary) the Sweep Level need to be adjusted to achieve the in-room SPL at which you wish to measure, typically 75 dB. This level should be checked using your SPL meter, if the SPL is lower or higher than desired adjust the replay volume, AV processor volume (preferred) or the Sweep Level (if connected directly to an equaliser, subwoofer or amplifier). The initial setting for the AV processor volume should be the level you normally use for listening.

If you are using a USB microphone put the input volume control to its unity gain (0 dB) setting, which is selected by default when the mic is first plugged in. The input level with a USB mic will usually be around -30 to -50 dBFS. If not using a USB microphone the input level should ideally be between -30 and -12 dBFS 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 interface or the OS audio level controls. Levels higher than -12 dB may result in input clipping during measurement, levels lower than -30 dB give noisier results, but neither is a hard limit.

Press Next to start the calibration signal or Cancel to quit.