Sorry, I have taken you down the wrong road, but this in your first post mislead me.-
"Have recently received new 'splitters' from Sky as the Sky BB guy, said the Noise was massive and needed to do something about it."

Splitters, or more correctly microfilters have nothing to do with wireless signals. Your stats show you are getting as much speed as you can, unless your noise margin improves in the test socket. You ca try that if you wish, but unless there is a lot of interference where you are plugged in now, you are not likely to get much more.

With regards wireless, do not trust the Auto setting on your router, even Sky's latest router is not too good at picking the correct channel. Look for a channel which is 2 channels clear of other users if at all possible. If all the channels are occupied, try No 13, although it is lapped by 11, it is often the best.