>>As far as calibrating, the Sub sits at -8.5 db relative to the mains being at +9.5, so quite a difference there.
As far as I know this difference is just a function of where you have the level control on the sub set. If you were to turn the sub level control down 10 dB you could then change the sub setting on the receiver up 10dB to +1.5dB...
... or better yet you could turn the sub down almost 20 dB and then bring ALL the receiver settings closer to zero
Seriously, there is a small chance that because the sub level control is turned up so high some kind of subsonic noise is getting in and making your cone flap. I don't *think* that is the problem but if you felt up to another "calibrate the sub" exercise it wouldn't hurt to :
- turn the sub down a bunch (whatever 20 dB is on the unmarked dial
)
- shift all the speaker settings down the same # of dB (suggest 9.5 to get mains at zero)
- recalibrate, but you shouldn't have to change anything except sub
