denon avr 2307 volume issue

After auto calibration???
If so, try turning down the sub on the actual sub and redo it.

What are the individual speaker volumes at?

Either on your reciever's digital display or the on screen menu it will show you each speakers individual volume ranging from -12db to +12db. Press enter or select on your remote and the FL speaker should come up first with it's volume. If it's closer to -12db you probably just have to turn them up as needed. My first reciever was a 2802. Good unit, clean power.

Cool, now crank it up all the way..........