Some advice required from fellow members please! I'm probably going to splash out and go for three Arca 400 series units (www.arcafurniture.net) to place under my screen in a new dedicated room (DIY thread coming soon). I'll be using 2 units with solid doors for equipment and the third unit, in the center with grille doors, to house my sub and center speaker. After silly quotes for custom cabinet builds I've decided the Arca is the best compromise. My sub is a Velodyne CHT-15 (from UE) and my center is a Monitor Audio Silver 12i. The internal height of the Arca 400 cabinet is about 23" which just gives me enough for the sub (21"high) and the center (22" long) - if I place them side by side with the center in an upright position. I'd like to get an idea if this is going to cause me problems ... How do subs perform when not directly in contact with the floor? Can I sit the sub on something inside the cabinet (rubber base or granite slab etc?) Will the center speakers performance be affected in any way because it's in a vertical position rather than horizontal? Should I pad the remaining space in the cabinet with some kind of acoustic material - foam etc? Thanks guys.