Supertrout

I've been using Avira for years on my pc's and never had a problem got paid for on one and the free version on the other. The free version is good if you don't mind a pop up every so often, stick it out for a while and they often offer you the paid for version for cheap, got mine £12 for 2 years.

Hard to say really its still got a crack to it as I've only ever used normal carts with it and not the subsonic's which would be quieter as you would loose the crack, but its not as loud as an unmoderated 4.10 and the sound doesn't appear to carry as far with the standard carts.