Well today I changed it all back again - well almost. The bass hump wasn't completely avoided by the new layout. It just depended what I played. Overall the sound was far too resonant and boomy. So now the system is back firing across the width of the room but I didn't put the furniture back. It stayed down the far end. The Dynaudios are sitting on chairs (I know but it's all I have at the moment  ). The kit is on slabs on the floor. It sounds better this way but still too lively and confused. I tried hanging a duvet from the picture hooks and light fittings. This lead to a much calmer drier sound and it was easier to hear what was going on. Removing the duvet bought the confusion back again. So now I need:

1) Speaker stands

2) A small equipment rack

3) Absorption

I have some of the carpet so I think I can make some simple absorbers for the lower part of the wall behind the speakers that should look alright.

Not sure about the upper walls. Some rockwool or foam covered in the curtain material perhaps.

Oh, and the Castles are still for sale