REW hints and tips

[John Mulcahy]

Here are a few hints and tips for using REW

• REW's mdat files can be opened by double-clicking on them or by dragging them onto the REW window
• Impulse response files in .wav or .aiff format can be imported by dragging them onto the REW window
• The measurement list can be navigated by using Alt+UP and Alt+DOWN to go up and down the list, or any of the first 9 measurements can be selected directly using ALT+1 or 2 or 3…9
• A measurement can be moved up or down in the list by selecting it then pressing and holding the left mouse button and dragging the measurement up or down to where you want it
• The graphs can be navigated by using Ctrl+LEFT and Ctrl+RIGHT to go to the next pr previous graph, or Ctrl+1 or 2 or 3…9 will go to the 1st, 2nd etc graph
• Moving the cursor over the name of a trace in the graph legend will highlight that trace in the graph
• If a measurement's name is shown in blue on the measurements panel it means it has been modified since it was loaded
• Use Ctrl+Shift+3 to apply 1/3rd octave smoothing, repeat to remove the smoothing. Ctrl+Shift+X applies variable smoothing
• If you accidentally delete a measurement use the Restore Last Removed entry in the file menu to recover it
• You can clear or select all traces in an overlay graph by right clicking in the legend area
• The graph can be moved by pressing the right mouse button and dragging
• The mouse wheel can be used to zoom in or out on a graph
• Variable zoom is available by pressing and holding the right mouse button, then while the right button is down pressing the left button, then drag the mouse
• You can measure between points on a graph by holding down the Ctrl key, pressing the right mouse button and dragging the mouse
• There are also keyboard graph controls: the cursor keys move the graph cursors; shift+cursor keys move the graph; x and shift+x zoom out/in on the x axis, y and shift+y zoom out/in on the y axis
• There are keyboard shortcuts for most actions
• To make more space for the graph (e.g. at lower screen resolutions) use the expand/collapse button above the measurement panels to reduce the width they take up and turn off the graph scroll bars using the button above the graph. You can also remove the labels under the toolbar and graph buttons by unchecking boxes in the View preferences to make more vertical space. You can also remove the toolbar by unchecking the Show toolbar box in the View preferences (everything in the toolbar has a corresponding menu entry and a keyboard shortcut).

High DPI screens

On MacOS REW automatically adapts to Retina displays. On Windows and Linux builds from V5.20 beta 54 onwards are high DPI aware. If the screen is above 96 DPI the fonts and icons will be adjusted to suit. Scaling of fonts can be enabled or disabled via a View preference setting Scale fonts for display DPI. Fonts will only be scaled if the resolution is more than 96 DPI.

On Linux it may be necessary to set the display DPI figure, for example using xrandr --dpi 192 to set 192 DPI.

Scaling will have no effect on Windows unless the High DPI scaling override is enabled with scaling set to Application. That property can be changed by right-clicking on the REW shortcut, selecting Properties, then the Compatibility tab, then the Change high DPI settings button.

 

[John Mulcahy]

Linux installation

• A Java 8 runtime must be installed first using sudo apt-get install openjdk-8-jre or equivalent. Do not install a headless JRE, they lack audio I/O.
• After downloading the installation file set permissions to allow it to run and install it as follows (example is for 5.19):
  $ chmod 777 REW_linux_5_19.sh
  $ sudo ./REW_linux_5_19.sh
• Start REW by running
  $ roomeqwizard

 

[Ballle Clorin]

How do I safely upgrade to a later release? Do I just install newer version or delete the old first? I am afraid to loose my old measurmentt files...

 

[John Mulcahy]

Just install the newer version.

 

[Hans - Peter Kreipe]

How to change the font size for an UHD display. The limit for me is 24 I would like to go to 36 or above.(Linux version used in Ubuntu)

 

[John Mulcahy]

I'll allow up to 48 pt in the next beta.

 

[Hans - Peter Kreipe]

That would be great. BTW: will the icons based on the value of the font size skaled, too?

Independent, thank you for the response and for the program?

 

[John Mulcahy]

No, but the underlying problem is with the JVM. It behaves properly on OS X but not on Windows or Linux (see this for more: http://openjdk.java.net/jeps/263 ). Java 9 looks to have addressed this, the fix might be backported to Java 8.

 

[Roald Theisen]

Using the REW V5.19 Beta 8 with macOS 10.13.3 there appears to be no way to change calibration when measuring impedance. The Change Calibration button, present in the Measurement Pane for sound measurements is simply missing in the same pane for impedance measurements.

Assuming this is a bug in this beta version (?), is there a workaround?

 

[John Mulcahy]

Calibration files don't apply for impedance measurements, they are ratiometric so cal effects fall out. There is only the impedance calibration that accommodates channel gain mismatch, that is done by setting the sense resistor value to zero before taking a measurement per the help.

 

[Krešimir Bikić]

John hi! Hi to all actually!

I have a question regarding surface apsorbtion values in Room Simulation Panel. Sorry if it's a dumb question but I'll give it a try anyway. I have found all over the net many tables with different materials and their values. That's clear. But I'm finding that these values vary in f(Hz) from lowest to highest... Should there be placed an average value in Room Panel (if I'm about to make measurement on the full spectrum, please see screenshot)? This is unclear to me. Please take into consideration that I'm an amateur and a noob in this field!

Thank you very much!

 

[John Mulcahy]

The simulator only covers the range up to 200 Hz, so use an average absorption value for that range.

 

[Castore]

I always copy the measurement note text and use it as the name for the mdat-file. I got used to the following routine: Click in the note area - Ctrl-a - Ctrl-c - Ctrl-s - Ctrl-v - Return. It worked for me for years until now (V5.19 Beta 9). Now the default file name (date) is not selected automatically. I need to select it manually to overwrite with "Crtl-v". This slows down mass savings. I hope you understand what I mean. Is there any preference option which could help my case? I'm using Win8.1
Is there any way to chain multichannel measurements to run sequentially with one start button click?

Thank you for a super nice and versatile measurement tool! I've been using it over ten years. I have made 1000 saved measurements during the last 12 months and at least 10 times more unsaved. REW is practically a standard among the hifi and home theater enthusiasts here in Finland.

 

[John Mulcahy]

I'd noticed the same. Seems that is a bug in the Nimbus look and feel, a bit of googling turned up a workaround that I'll include in the next beta release.

 

[Niklasmagnus]

Hi, I´m not able to remove smoothing, it´s "like" default 1/48 if I click "no smoothing". I´m missing some function here?
Run newest 64 bit version.

 

[John Mulcahy]

That's a side effect of the "Allow 96 PPO log Spacing" Analysis preference. With that option selected measurements may be converted to 96 points per octave log spacing rather than linear spacing, which greatly reduces the file size and memory use of the measurement. The conversion only happens if the result will be smaller than keeping linear spacing, which is usually the case for full range measurements. The tradeoff is the measurement needs to have 1/48 octave smoothing to prevent aliasing. If the option is deselected then using "Apply windows" in the IR Windows dialog will regenerate a linearly spaced measurement.

 

[Niklasmagnus]

Thanks, i found the setting. Have unchecked it now and I get "no smoothing" by default on measurement.

 

[Michael Beck]

If you hover the mouse cursor over the name of a measurement in the overlay panel it will bring up a tool tip showing the measurement notes

I can't get this to work on my Win10 machine running REW v5.19 . It's probably a setting in the pc but any help appreciated.

 

[John Mulcahy]

That was removed in 5.19, I'll remove it from the tips.

• No longer show measurement notes in tooltip for overlay graph legend selectors (gets in the way)

 

[Michael Beck]

I find the tooltip feature extremely valuable when viewing a lot of measurements on the overlay screen. Could it be added as an option in preferences in a future release? Meanwhile I'll downgrade. Thanks

 

[John Mulcahy]

Yes, I'll add that to the todo list.

 

[CAAudiophile]

Hi John,
I am trying to time align my speakers using the Step response however my question is regarding the "Minimum Phase" vs "Excess Phase" how are both calculated in the REW?
My understanding is the:
( Excess phase = Frequency Response - Minimum Phase)

Regards.

 

[John Mulcahy]

The minimum phase response is calculated using the real cepstrum, though it isn't really relevant for time aligning speakers. For that the speakers need to be measured with a common timing reference (a loopback connection or an acoustic timing reference) and REW will directly provide the delay relative to the reference.

 

[CAAudiophile]

Thank you John, I'm using the soundcard "Focusrite" with a loopback. not sure how to relate the Delay to it unless it is done automatically ... If you could please explain the proper way to do the time alignment.
The way I am currently time aligning my speakers is by taking the excess phase response from the frequency response curve for each driver Mic at the listening position, "say" left channel (3way system) and time align the drivers using the excess phase curves for each one.
A- I am not sure about how to reference the loopback to the delay.?
B- Do you use the Peak or the Rising edge of the signal for the alignment?


Regards,

 

[John Mulcahy]

Using a timing reference is described in the help. If you have a loopback connection and select "Use loopback as timing reference" on the Measure dialog REW will calculate a delay figure relative to the loopback and show it in the notes for the measurement and in the System Delay entry in the measurement Info panel. Excess phase (or excess group delay) can only be compared between measurements if the measurements used a timing reference of some sort.