Hi,
Typical settings would be to keep the sub on and volume on subwoofer kept at 40 to 50% and then run auto setup on the AVR.
The AVR setup will calibrate tonal frequencies and levels for all speakers and you can enjoy optimal playback.
Still if you feel something is lacking and levels are low, refer to AVR operations manual and do some adjustments slowly as listed for each channel etc.
If the subwoofer is found to be too boomy in the placed area, reduce the volume slightly on the sub and check again with your favorite music and movies....sometimes you may need to do the SUBWOOFER CRAWL method to find the best placement..
Do these things and get back on if it worked or not. You need to do all this with patience, never rush!