Using Room EQ or Headphone EQ as a system wide equalizer on Mac

Room EQ AU and Headphone EQ AU can be used as system wide equalizers to process all audio on your Mac (movies, music, games) and enhance your experience with iTunes, YouTube, Spotify, Netflix, etc.

You need two free programs: Download and install both AU Lab and Soundflower, then restart your Mac to have full access to the audio components. Once rebooted, follow along with one of the instructions below.

1. Instruction for Room EQ

1.1. Download and install Room EQ AU.
1.2. Launch AU Lab, found in /Applications/Utilities/
1.3. From "Factory Configurations" menu select "Stereo In/Stereo Out". From "Audio Input Device" menu select your microphone input and from "Audio Output Device" menu select the output which corresponds to your speakers.
1.4. Click the "Create Document" button at the bottom of the screen. Make sure that you hear the sound of the measurement microphone in one of your speakers when you touch the measurement microphone. If the sound is absent and you use USB speakers, you need to manually set the necessary inputs and outputs in AU Lab as it is described here.
1.5. At the next screen, look for "Output 1" column and click the "Effects" dropdown, selecting "MathAudio Room EQ".
1.6. Make sure that the green indicators show the presence of the mic signal (see figure below).
Indicators
1.7. Measure the frequency response of your room in accordance with the items 5 and 6 of the Room EQ Help manual. Make no less than 5-20 measurements within the area of possible locations of all listeners. Use the "Save preset" button to save the frequency response as a .snr file.
1.8. Quit AU Lab without saving.
1.9. Open System Preferences from the Apple menu and select the "Sound" panel, followed by the "Output" tab. Select "Soundflower (2ch)" from the Output list.
1.10. Launch AU Lab once again. From the "Audio Input Device" menu, select "Soundflower (2ch)", and then from "Audio Output Device" menu select "Line Output". Click the "Create Document" button at the bottom of the screen and select the "MathAudio Room EQ" plug-in.
1.11. Click the "Load preset" button to load the .snr file with the frequency response of your room.
1.12. Click the "Room EQ" radio button. Use iTunes or any other audio software to play music. Set the position of the vertical slider and other controls in accordance with the items 7..14 of the Room EQ Help manual.
1.13. Close the Room EQ window.
1.14. Hit Command+S to save the EQ settings file and put it somewhere easy to find like the Documents folder.
1.15. Now open AU Lab preferences from the AU Lab menu, click on the "Document" tab and click the radiobox next to "Open a specific document", selecting the .trak file you saved in the previous step.
1.16. Click "Hide AU Lab" in AU Lab menu.
1.17. If you want the Room EQ settings to load on every Mac OS X boot, right-click on the AU Lab dock icon, go to Options, and select "Open at Login". Then check "Reopen windows when logging back in" in the "Shut Down" dialog when you shut down your computer.

2. Instruction for Headphone EQ

2.1. Download and install Headphone EQ AU.
2.2. Open System Preferences from the Apple menu and select the "Sound" panel, followed by the "Output" tab. Select "Soundflower (2ch)" from the Output list.
2.3. Launch AU Lab, found in /Applications/Utilities/
2.4. From "Factory Configurations" menu select "Stereo In/Stereo Out". From the "Audio Input Device" menu, select "Soundflower (2ch)", and then from "Audio Output Device" menu select "Line Output". Click the "Create Document" button at the bottom of the screen.
2.5. At the next screen, look for "Output 1" column and click the "Effects" dropdown, selecting "MathAudio Headphone EQ".
2.6. Click the "Sweep" radio button in the Headphone EQ window. Correct the frequency response of your headphones in accordance with the items 5..12 of the Headphone EQ Help manual.
2.7. Close the Headphone EQ window.
2.8. Hit Command+S to save the EQ settings file and put it somewhere easy to find like the Documents folder.
2.9. Now open AU Lab preferences from the AU Lab menu, click on the "Document" tab and click the radiobox next to "Open a specific document", selecting the .trak file you saved in the previous step.
2.10. Click "Hide AU Lab" in AU Lab menu.
2.11. If you want the Headphone EQ settings to load on every Mac OS X boot, right-click on the AU Lab dock icon, go to Options, and select "Open at Login". Then check "Reopen windows when logging back in" in the "Shut Down" dialog when you shut down your computer.