210 sixty five much louder thru 2x12?

I just put some reconed k110 jbl's in my 210 sixty five, sounds great but doesn't get loud really.
However when I add the 2x12 extension its nice and loud.
Is this normal, or have possibly got the k110's wired up wrong?

yes

yes its wired wrong?
or
yes its normal that this happens?
TIA

If you have the extension cab and the onboard speakers going, it should be louder since you're moving more air.
At the same time, incorrectly wired speakers will also be quieter. I think as long as the positive and negative terminals hooked up to the appropriate leads, that should do it.

alex got it ,it was yes to the wiring possibly being incorrect.