What is the difference between the ETM, EFR and EMD formats?
There are basically three native file formats available in EASERA: EMD, ETM and EFR.
EMD is a time domain format that also saves the raw measurement data. Generally this is recommendable to use during measurement sessions as it allows for later inspection of the actually recorded raw input data.
The ETM contains the IR data only, but it is otherwise identical with the EMD. It is useful if you are not interested in keeping the raw data or if you just want to save some overlay files.
The EFR file format is the frequency domain file of EASERA, however with the inclusion of optimized FFTs it seems already a little bit obsolete today. But, if you work a lot for example with loudspeaker frequency response a format that always opens in the magnitude display may be more convenient.