Right. Swifty55, i tried that test socket.
I plugged into my BT master socket downstairs and got the same 4mb with the same lame attenuation. BUT then i unscrewed the cover thing off the master socket, and plugged in my line into the test socket, connected to the router through the laptop and BAM i get 6mb instead of 4mb. Which would fall in line with your nice useful little graph there.
So i'm getting 4mb in the master socket, but 6mb in the TEST socket on the master socket. I'm guessing the test socket bypasses that ring wire thing? So the next step, is to disconnect this ring wire thing?
I need help doing this guys. I took a quick look before i put everything back in it's place, and i saw 3 wires. One going into terminal 2, one into terminal 5, and this other orange one in the middle somewhere in either 3 or 4.
I assume this is the ring wire? What do i do? Pull on it? Cut it?