Are my filters wrong?

I saw Chainik question the use of ffdshow audio in this thread and it got me thinking about my own filters. I'm using ffdshow audio but I have no idea why. I don't remember setting it up, same story with AC3Filter which I don't even remember ever using before. Some time ago I uninstalled everything and did a fresh install of SVP, so I don't know why these things are here.
Are these leftovers from something else? How do I get rid of everything I don't need and just use defaults?

Filters currently loaded:
  - Default DirectSound Device
  - madVR
  - Audio Switcher
  - ffdshow raw video filter
  - AC3Filter
  - ffdshow Video Decoder
  - ffdshow Audio Decoder
  - LAV Splitter (internal) (low merit)
  - File Source (Async.)