The best bet with the analog is to disable the Toshiba's bass management entirely and let the settings already configured in the 990 take care of bass management for you. To disable the Toshiba's bass management, go into the Toshiba's audio settings and set all speakers to large, the sub to on, and zero all the speaker levels. I hadn't heard about the sub signal on the Toshiba being low, but if that's the case regardless of source you can set the sub trim in the Toshiba's menu to +10 and if it's an inherent issue with the Toshiba's sub output that'll equalize it with the other sources you're using.