air absorption calculator

This calculator helps determine where to time‑align main speaker and subwoofer within an audience plance.

For an instruction video, please click here.

Sub Align is also featured in my article "Displacement is Key" which discusses the decision‑making process of whether or not to co‑locate mains and subwoofers.


  • metric and imperial

file type: Microsoft Excel Open XML spreadsheet (.xlsx)

minimum requirements:

  • Excel 2007 or higher
  • Excel 2008 or higher

download calculator:

I am proud an honored of having inspired Pavel Smokotnin — developer of Open Sound Meter — to volunteer and develop a free iPad app of my Sub Align calculator. Thank you so much Pavel for spending time and resources on creating this open‑source project!

SubAlign for iPad by Pavel Smokotnin

The iPad app is available from the App Store as well as for MacOS and Windows using this link.