Something to keep in mind is that both my ISP and my company offer Virus Protection to their users at no extra cost. It's worth looking into before you choose to pay.
FWIW, I have not installed any Virus Scanner beyond Windows Defender in 10 years. One of the original purposes of Giant AntiSpyware which is the original source of what became Windows Defender was to protect your privacy by scrambling bits on your hard drive for old deleted documents and deleting cookies from IE... that sort of thing. This was removed from Windows Defender.
http://en.wikipedia.org/wiki/Windows_Defender BTW, if you want a search engine that is at least trying not to track you, check this one out...
https://duckduckgo.com/ It was the default search engine in my most recent Linux Install. I thought it was worth knowing about.
Lastly, notice that you can exclude File Types, Processes and Locations from the scanner. This can be pretty helpful in making sure it doesn't get in the way of your recording process. What's the chance that one of your WAV files will have a virus in it?