Sub Align
Helps to select a position for the microphone to align mains with subwoofers.
Original calculator was created by Merlijn van Veen as Excel file. It is a version than works as native application on all the platforms and doesn't need MS Office installed.
This project is also open-source, you can contribute to the project on GitHub!
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More useful calculators by Merlijn van Veen you can find here