REW Room EQ wizzard
Download: http://roomeqwizard.com/installers/
Support Forum: http://www.hometheatershack.com/forums/rew-forum/
Installation:
- Run the installer
- Replace open JDK java by Oracle Java, otherwise it is impossible to generate sound.
https://launchpad.net/~webupd8team/+archive/ubuntu/java
http://www.wikihow.com/Install-Oracle-Java-on-Ubuntu-Linux
http://www.oracle.com/technetwork/java/javase/downloads/index.html
Calibrating the microphone:
Umik-1 comes with a downloadable calibration file to compensate the non flat frequency response
http://www.minidsp.com/products/acoustic-measurement/umik-1
It is not possible to make reliable SPL measurements, as the microphone input level can be controlled by
the PC's sound mixer.
Also setting the microphone input level with the sound mixer is not accurate as you don't see the exact value
of the input gain, therefore it is necessary to be able to set the input gain via the command line to a well
defined value.
In linux, this can be achieved with the following command:
marc@marc-tec:~$ amixer -c 1 set Mic 10
Simple mixer control 'Mic',0
Capabilities: cvolume cswitch cswitch-joined
Capture channels: Front Left - Front Right
Limits: Capture 0 - 55
Front Left: Capture 10 [18%] [-21.00dB] [on]
Front Right: Capture 10 [18%] [-21.00dB] [on]
amixer controls the Alsa soundmixer,
-c selects the soundcard (0 = PC soundcard, 1 = Umik-1)
set Mic 10 sets the value of the microphone to 10
the output shows the values of the microphone input gain settings
In Windows there exists a tool that enables to set all kinds of parameters via the commandline nircmd
http://blog.nirsoft.net/2011/06/29/3-new-nircmd-commands-to-control-the-sound-volume-on-windows-7vista2008/
http://www.nirsoft.net/utils/nircmd2.html#using
You can download it at
http://www.nirsoft.net/utils/nircmd.zip
http://www.nirsoft.net/utils/nircmd-x64.zip
You need to set the input gain to a value that does not saturate the mic or PC input amp at the SPL you want to measure.
In order to do that:
- Generate the desired sound via REW SPL meter by clicking on Calibrate and use the speaker or subwoofer cal signal.
- Measure this sound with a calibrated SPL meter and set the volume to the desired SPL you use for testing (typically 75dB(C))
- Adjust the REW SPL reading Calibration to match the reading on the calibrated SPL meter and hit "Finished" to store this in REW.