问题
Is it possible to access system audio using the Web Audio API, in order to visualize or apply an equalizer to it? It looks like it's possible to hook up system audio to an input device that Web Audio API can access (i.e. Web Audio API, get the output from the soundcard); however ideally I would like to be able to process all sound output without making any local configuration changes.
回答1:
No, this isn't possible. The closest you could get is installing a loopback audio device on the user's systems, like Soundflower on OSX, and use that as the default audio output device. It's not possible without local config changes.
来源：https://stackoverflow.com/questions/29594405/access-process-system-audio-with-javascript-web-audio-api