I run a 7w Matamp through its matching 1x12 cabinet. It is capable of rattling the double glazing and, if I crank it, it can be heard in the neighbours garden across the road. Fortunately I live in a detached house so using it in the spirit intended is occasionally possible but it still isn't even remotely sociable!
If you're thinking that a 2x12 is going to be significantly kinder to your neighbours, think again.... A 1x12 is more than enough to get you an ASBO so perhaps turning down or (horror of horrors) looking at a modelling solution until you move might be better?
I obviously don't know your neighbourly situation but if your idea of appeasing them is running full blast through 2 12 inch speakers rather than 4 I'm starting to feel for them