Reference¶
These pages are the background theory behind what cftscal does. You don't need any of it to run a routine calibration — start with Calibration Concepts and the plugin workflow pages for that. Come here when you want to know why a number looks the way it does, check cftscal's arithmetic against your own, or design new hardware that cftscal will later calibrate.
-
Calibration Math
Every equation cftscal uses, from pistonphone to "what voltage do I send to the speaker for 80 dB SPL?", plus the sign and unit conventions you need to interpret the numbers the GUI reports.
-
Signal Analysis
Windowing, power spectral density estimation, spectrum level vs. band level, chirps, and reproducible filtered noise. Read this if a measured level or spectrum isn't what you expected.
-
Hardware Design
Choosing safe drive voltages for a speaker, estimating its maximum output, sizing a voltage divider, and the cable and acoustic-tube resonances worth (and not worth) worrying about.