I set up my home cinema speaker levels using SPL meter (slow response and C-weighting, according to various guides like "What Hifi" magazine). However, I find that the rear speakers are too quiet and I miss out on the more delicate sounds. I increase their levels up one or two notches and I hear background sounds that I would've never known (eg birds singing in beginning of 1st LOTR film, etc). However, when there are louder sounds from the rear channels, they are too damn loud and drain out the fronts, and it sounds unnatural. When I lower their levels back down to what the SPL suggests, so the loud moments are acceptable again, I still miss out on the quieter sounds. So how much is too loud and how much is too quiet, for rear channels? Thanks.