Feedback from a new REW user (Spinorama / ground plane measurements)

[Finnito]

Hi John and all,


First of all: REW is a great program and I really enjoy switching to it. For context, I have used Systune and ARTA for several years. I mainly measure loudspeaker Spinoramas on a turntable, plus ground plane measurements. I’m far from an REW expert and use the German UI, so please excuse any wrong terminology. Some observations, in no particular order:

1. Window settings in the Measure dialog. Default IR window settings for new measurements can only be set in Preferences. It would be very helpful to set at least the right window directly in the Measure dialog.
2. Applied time offset is not visible afterwards. I use the time offset a lot to align all measurements to one driver, and it works well. But afterwards I can’t see which offset was applied to a measurement. If I forget to change the offset during a session, I can’t find or correct the mistake later. Could the offset be stored in the measurement info?
3. Window reference with loopback timing reference. With a loopback timing reference, the window reference is always set to the IR peak. On the turntable, the reflection is sometimes stronger than the direct sound, so the window ends up in the wrong place. An option to reference the window to the IR start (or the first arrival above a threshold) would solve this.
4. Measurement selection for All SPL. Selecting which measurements is selected All SPL requires going back to the SPL & Phase tab, which I find confusing. I don’t have a better solution, I just wanted to mention it.
5. Comparing phase between measurements. Currently this only works via Overlays. It would be great to compare two measurements directly in SPL & Phase, e.g. via Ctrl+click. I often merge ground plane and gated measurements for the on-axis response, and a quick SPL and phase check there would save time.
6. Native file dialogs. I struggle with the Java file dialog. Almost all other software uses the native OS dialogs. An option to use them would be much appreciated.
7. Log/lin frequency axis button. The log/lin button is quite large. It could move into the GUI elements settings, like the scroll bar buttons.
8. FDW cycles: definition compared to other software? With FDW set to 1 cycle, REW smooths noticeably more than Systune with the same setting. How does REW define the number of cycles: full or half window width, and which window shape? Knowing this would help when comparing results between programs.
9. Language is fixed on system language
10. Naming of “Merge B to A”. The name doesn’t make clear that B is used below the transition frequency and A above it. Something like “Merge: B below / A above”, or labelling the frequency field “Use B below: X Hz”, would make this obvious without checking the manual.

Thanks for all the work on REW!


Finn

 

[John Mulcahy]

Applied time offset is not visible afterwards

Click the Info button.

Measurement selection for All SPL

You don't mention which version you are running. If it's 5.40 beta double click the measurement you want selected for the individual graphs.

How does REW define the number of cycles

Full width at half maximum. Shape is Gaussian.

Naming of “Merge B to A”. The name doesn’t make clear that B is used below the transition frequency and A above it.

Seems obvious to me, going from B to A.

 

[John Mulcahy]

Window reference with loopback timing reference

Go to the on-axis measurement and use Apply windows to all on the IR windows dialog.

 

[dcibel]

Window reference with loopback timing reference. With a loopback timing reference, the window reference is always set to the IR peak. On the turntable, the reflection is sometimes stronger than the direct sound, so the window ends up in the wrong place. An option to reference the window to the IR start (or the first arrival above a threshold) would solve this.

When measuring spatial data, typically one would want to utilize the same window and time reference for all measurements in the data set, so default set by the measurement is not relevant. For my workflow, it would be to measure all spatial measurements, then set the desired window using the 0deg on-axis measurement, then "apply window to all".