The phase of a measurement is usually not minimal phase, due to influence of the room (reflections). REW can calculate via FFT the minimal phase from the frequency response.

To create minimal phase copy for a measurement do the following steps:

1. Select the “All SPL” tab
2. Select the measurement that you want to create minimal phase for
3. Select “Actions” and “Measurement Actions”
4. Press “Minimum Phase Version”

This will create a new measurement with phase measurement replaced by a minimal phase version.

To create minimal phase trace for a measurement do the following steps:

1. Select the “SPL & Phase” tab
2. Select “Actions”
3. Press “Generate Minimum Phase”

This will not create a new measurement. But will add a minimal phase trace to the SPL.