Looks like you have narrowed it down to the laptop, so I'd be looking at when your USB / ASIO drivers were last updated and see if you can roll them back.
I'm guessing that you are using the headphone jack or line out on the Focusrite as the output to your sound system, what is the quality like when using the headphone jack of your laptop to provide the feed.
Try it with the 2i2 both connected and disconnected, if the sound is good then there is a problem in the USB area only, if it goes bad with the 2i2 connected then it looks like an A/D issue to me