I would go somewhere I could get a new wireless n router that will let you return it if it doesn't fix the problem. If you have a lot networks make sure it does 5Ghz

If you'd invite me over for some cocktails and a steak I'd bring one with me so we can start from the modem and work our way in.

Oh that's right, you're hours ahead of me.

The tried and true technique, start from the plug/source and work your way in.

Or is it your son expecting too much from your connection?