Can someone help me? Something is bothering me right now. Using my Avia disc, with the sound test for Low Frequency (200 to 20 Hz) Sweep, I seem to get a roller coaster ride with my Radio Shack SPL meter. I set it at C-weighting, Slow, and try to set the volume to produce around 70db. I also turned-off my sub to take it out of the equation. There are frequencies where in the reading would peak to the right end (around 150Hz and 55Hz) and there are others where it would go down to the left. Is this normal? That the sound level go from 60db to 80db using that test tone? I feel that because of this, the sound of the speakers doesn't scale smoothly when listening to music. My speakers are Wharfedale Diamonds.