What this is for
Soundz is a set of browser tools for checking headphones, speakers, microphones, and the arithmetic around audio. Tones are generated on your machine. Microphone audio stays in the tab.
How to use the result
The limit is the point of the writing under each tool. A sweep is not a hearing test. A decibel formula is not a sound level meter. A Bluetooth frame count is not a codec report. The tools stay inside those lines.