Here are two spreadsheets for use in audio design.
Loudspeaker Design
This spreadsheet may be used to calculate Thiele-Small parameters from driver measurements or, if parameters are known, enter these into the spreadsheet and use these parameters to examine the driver response and tuning for various sealed and vented enclosure designs.
Loudspeaker Design Spreadsheet
Room Acoustics
A simple spreadsheet that shows the room modes when the room dimensions are entered. This allows examination of room dimensions and an estimation of where the problem frequencies will be. It only applies to rectangular rooms.