Builds updated today (beta 43) with these changes:
- Added: Measurements can be grouped
- Added: The SPL & Phase graph has an option to show the musical note corresponding to the cursor frequency
- Added: There are View preferences to set the tuning frequency for musical notes (default is 440 Hz) and choose the octave notation style
- Added: Audison/Hertz equaliser entries
- Added: Vector sum action in All SPL graph to add multiple measurements
- Added: API endpoints to get the UUID of the selected measurement and select a measurement by UUID
- Added: API endpoint /generator/full-scale-vrms to get/set the full scale rms voltage figure
- Changed: Ctrl+TAB through measurements right click menu cycles through name and notes fields only
- Changed: Voltage axis can go up to 1000 V
- Fixed: Deleting the current measurement selection changed the EQ target of the preceding measurement to the default
- Fixed: Flac file duration could be incorrect
- Fixed: Crossover frequency figure shown in notes of measurements generated from room sim responses could be incorrect
- Fixed: Typing a value in the right click menu SPL offset control and then clicking Add to data would not add the offset to the data
- Fixed: Importing responses via the API could cause an exception
- Fixed: Distortion overlay could show "None of these measurements have distortion data" when first opened
The big change is the ability to group measurements. That's covered in the
measurements panel help, here is an example view:
Measurements can be added to groups by right click and there are options in the groups menu (
) to add measurements of different types to groups, along with an option to automatically create groups from the filenames of measurements as they are loaded.
On the overlays graphs (including All SPL) collapsing a group will deselect all its measurements, expanding a group will select all the group's measurement though there is an option to disable that in the group menu.
There are
API endpoints for group management. Note that it is strongly recommended to reference measurements by their UUID rather than index, since the index is not reflective of the display order when measurements are grouped.
To preserve group arrangements for a set of measurements save the mdat file after setting up the groups. The mdat file contains group settings, but remains backwards compatible with earlier REW versions that don't support groups.
Adding groups has involved a fairly extensive rewrite of REW internals, if you notice odd behaviours please post about them here so they can be addressed promptly.
. I think a hit a bug on REW 5.40 beta 42 when importing impulse response through API. I'm just working with the great tool A1Evo from 
