Without knowing any more than you have provided my guess would be that when you are watching T.V. or listening to Pandora you are not getting a LFE signal. Many Televisions do not support 5.1 over the SPDIF\TOSlink. If your TV has an HDMI output that would be the best way to get the LFE from television shows but will do nothing for Pandora. Most likely what you want to do is change you subwoofer setting in the receiver from LFE to LFE+MAINS. With this setting you will send all bass below your crossover set point to the sub and not just the LFE signal.