The most obvious use for a frequency tone generator is to test speakers. Knowing what frequency a speaker can reproduce is very important when setting crossover points.
To use this frequency tone generator to test any sort of output, you first need to attach the device you are viewing this site on to your audio equipment. How this is done will abvously depend on what device you are viewing the Frequencygen frequency tone generator on and what device you want to send the sound to. In my case, I am usually testing car audio so view the Frequencygen frequency tone generator on my phone and connect it to the headunit 3.5 aux in via the phones 3.5 headphone jack.
Play a test tone at the lower frequency that you want to start testing at, then gradually raise the frequency via the slider of the frequency buttons. While this method is not too accurate as everyones hearing is different, it should give you a general idea.
You can test speaker balance simply by shifting the balance slider to the left and right.
To test speaker phase, slide the balance from left to right and listening for when there seems to be more output. If there seems to be more output when the balance is centered it means the speakers are correctly wired in phase. If there seems to be more output when the balance is either to the right or left, then the speakers are probably wired out pf phase and you should check your speaker wires.
Typically when connecting a subwoofer to an audio system you will set a low pass filter on the subwoofer output/amplifier. When doing this you would not want you other speakers to output at these low frequencies which would be taken care of by the subwoofer. Using an audio tone frequency generator allows you to check at what frequency the non subwoofer speakers start to drop off in output and where to set the low pass filter on your subwoofer.
When selecting the record button, this Audio tone frequency generator will record the audio for up to 10 seconds. A link will then be generated so you can download the recording. The file type will be determined by the browser you are using and the audio formats it supports. Chrome will probably generate a ".webm" file and Firefox an ".ogg" file. You can convert these files to other formats with online audio conversion tools or with the Free software called Audacity