Max db at 20hz?

[Extra Gravity]

I realize that when Devialet advertises Phantom Gold/Silver/White as producing 108/105/101 db, they are not referring to the bass spectrum at 20 hz.  Anyone know what the figure would be at 20hz?  More a curiosity than anything.

Thanks.

Can anyone remind me, at which numbers on the Spark volume indicator, do the low frequency's starts rolling off  slightly? Think it's 65 or 70 but can't quite remember.