Welcome to REW

REW (Room EQ Wizard) is a Java application for measuring room responses and countering room modal resonances. It includes tools for generating test signals; measuring SPL; measuring frequency and impulse responses; generating phase, group delay, spectral decay plots, waterfalls, spectrograms and energy-time curves; generating real time analyser (RTA) plots; calculating reverberation times; displaying equaliser responses and automatically adjusting the settings of parametric equalisers to counter the effects of room modes and adjust responses to match a target.

REW uses a logarithmically swept sine signal for its measurements. This is much faster than manual measurements, more accurate, less likely to suffer from clipping at resonances, less sensitive to system non-linearity than MLS and allows the impulse response of the room to be determined, which in turn is the basis for many additional features. When using the Real Time Analyser displays REW can generate Pink Periodic Noise sequences for much better visibility of low frequency behaviour than obtained using random Pink Noise without the need for lengthy averaging.

Requirements

• REW can be used on Windows XP Pro x64/Vista/7/8/8.1/10/11, macOS 10.15 or later and Linux. 32-bit builds of Win XP are no longer supported.
• Minimum screen resolution: 1024 x 768
• Minimum RAM: 2 GB, 4 GB or more recommended
• The Windows and Linux AMD64 installers include private Java runtimes for use by REW if a Java 8 runtime is not already installed. A separate Linux installer without runtime is provided for architectures other than AMD64, a Java 8 runtime must be installed to use that. Do not install a headless version of the Java runtime, they lack audio I/O
• The macOS download includes a private Java runtime for use by REW. Java does not need to be installed. Microphone access permissions are part of the code signature and should be automatic. To force a mic access permission prompt for REW run

  tccutil reset Microphone

  from a terminal before starting REW
• RS232 serial communications (only used to communicate with TAG McLaren Audio AV32R DP and AV192R AV Processors) only function on Windows 32-bit systems.
• Midi communication (used to set filters on Behringer BFD Pro DSP1124P and FBQ2496 equalisers) is supported on Windows. macOS should also support Midi.

Windows XP Pro x64, Vista, 7, 8 or 8.1

When installing REW on Windows XP Pro x64, Vista, 7, 8 or 8.1 you may encounter a somewhat cryptic error message:

"The program can't start because api-ms-win-core-timezone-l1-1-0.dll is missing from your computer. Try reinstalling the program to fix this problem.".

This is caused by the Java runtime using components from the Windows Universal C Runtime which are not present on older Windows installations. To fix it see this Microsoft knowledge base article, KB2999226 at https://support.microsoft.com/en-us/help/2999226/update-for-universal-c-runtime-in-windows.

Linux installation

• Open a terminal window in the folder where the installation file was downloaded
• After downloading the installation file set permissions to allow it to run and install it as follows (example is for 5.19):

  chmod u+x REW_linux_5_19.sh

  sudo ./REW_linux_5_19.sh

• If your terminal working directory is not where the installer was downloaded include the path to the downloaded file. For example, if the terminal is open in your home directory and the installer was downloaded to the Downloads folder put Downloads/ in front of the installer filename.
• Start REW by running

  roomeqwizard

Diagnostics

REW saves diagnostic logs in the user's home directory in a folder called REW, the location is displayed in the Help → About REW window. The logs contain information from the last 10 startups, including any error messages or warnings that may have been generated. On macOS the logs are in an REW folder in the user library folder, which no longer appears in Finder by default. To display it either browse to ~/Library/Logs or open your Home folder in Finder (Shift Command + H), select View > Show View Options then select the checkbox to show the library folder.

REW saves a temporary copy of each measurement in a /temp sub-folder of the logs folder. Seven days of measurements are retained, any older than 7 days are deleted on shutdown. If REW did not shut down normally it will offer to load any measurements made since it last started up.

Java Runtime Environment options

The roomeqwizard.vmoptions file in the REW program directory contains settings for the Java Runtime Environment (JRE). The REW installer makes an entry in the file to define the amount of memory to request fore the JRE on startup using the -Xmx option, for example -Xmx1024m for 1 GB. The file could be edited to request a memory size larger than the installer offers, such as -Xmx4096m for 4 GB, but note that if the OS refuses the request for the memory size specified in the file REW will not start.

On Windows Admin privileges are required to change the roomeqwizard.vmoptions file: copy it to a user-accessible directory, make the edits, then copy it back using Admin privileges.

As an alternative to editing the roomeqwizard.vmoptions file parameters can be passed to the runtime via the command line (e.g. by editing the Target of a shortcut). To do that they must be preceded by -J, so to force REW to start with 4 GB allocation (for example) regardless of the contents of the vmoptions file the shortcut target on Windows could be
"C:\Program Files\REW\roomeqwizard.exe" -J-Xmx4096m

REW Preferences

By default the preferences for REW on Windows systems are stored in this registry key:

HKEY_CURRENT_USER\Software\JavaSoft\Prefs\room eq wizard

On macOS the preferences are stored under a key called room eq wizard in:

~/Library/Preferences/com.apple.java.util.prefs.plist

Linux preferences are typically stored in:

~/.java/.userPrefs/room eq wizard/prefs.xml

REW can alternatively use a file for its preferences. There are three ways to configure that, The easiest is to put a file in the REW log files folder with the name rewprefs.txt. If that file is found on startup REW will use it to store all preferences. To use a different file run REW with a -prefs argument or make a -Drew.preferences.file entry in the roomeqwizard.vmoptions file. The -prefs argument is checked first, then the -Drew.preferences.file entry and finally REW looks for rewprefs.txt. Switching to file-based preferences can be done quickly by saving preferences to rewprefs.txt in the log files folder using the entry in the Preferences menu and restarting REW. On Windows systems startup is faster with file-based preferences.

On Windows with the default REW installation a preferences file could be specified by launching REW using

C:\Program Files\REW\roomeqwizard.exe -prefs "C:\Users\johnm\Documents\myrewprefs.txt"

or editing the Target field of the properties of an REW Windows shortcut to add the prefs argument, so the target would look like

"C:\Program Files\REW\roomeqwizard.exe" -prefs "C:\Users\johnm\Documents\myrewprefs.txt"

On macOS it could be done from a terminal using

open -a REW.app --args -prefs "/Users/johnm/Documents/myrewprefs.txt"

To use the roomeqwizard.vmoptions file add an entry to specify the path to the file, for example:

-Drew.preferences.file=C:\Users\johnm\Documents\myrewprefs.txt

If a preferences file is being used the file name will be shown in the About REW dialog. If the specified file cannot be accessed, created or written to REW will instead use a file called rewprefs.txt in the REW log files folder and show a warning to that effect.

A preferences file can be created from an existing installation using the Preferences → Save preferences to file menu entry.

Preferences can be deleted with the Preferences → Delete preferences and shut down menu entry or by running the REW uninstaller.

Initial preferences

REW can be made to always start with an initial set of preferences by specifying a file with those initial values. There are three ways to do that. The easiest is to put the file in the REW log files folder with the name initialprefs.txt. If that file is found on startup REW will use it to initialise all preferences. To force preferences to be initialised from a different file run REW with a -initialprefs argument specifying the file name for the starting preferences, or add a -Drew.initialpreferences.file entry in the roomeqwizard.vmoptions file. The -initialprefs argument is checked first, then the -Drew.initialpreferences.file entry and finally REW looks for initialprefs.txt. If a preferences file has also been specified REW will copy the initial preferences to that file, if not it will create a preferences file and copy the initial preferences into it. Any file specified as the initial preferences should be different to the file specified for the preferences. Note that the initial preferences file does not need to contain all preference settings. It can be edited to contain only those preferences which are to be initialised, any not included in the file will not be altered.

No Warranty

THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE

Acknowledgements

Copyright © 2004-2023 John Mulcahy All Rights Reserved

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