I have tried a new way to record raw audio from any website online. You might refer to the steps below:

Step 1: download and install Replay AV from this link. You can try it for free. And then run it on your computer.
Step 2: go to http://lessthan3.com? and play audio.
Step 3: click "Record" button on streaming audio capture to begin to record audio.

Also, it has many other choices for you.