I've configured my HDMI output for 7.1, going to an 11.1.4 soundbar+subwoofer+rears. In the 15-130Hz range, the SPL measurements I get measuring the sub (.1) channel are about 10 dB higher than what I measure on any of the other 7 channels. Which should I pay attention to when trying to balance levels? Or do I need to balance separately for stereo vs n.1 channel sound?