Hey, new member here! Look forward to digging in and sharing information where ever I can.

I have an '07 C280 4Matic with the 12 speaker Harmon Kardin sound system. Is anyone familiar with the speaker layout? I can only see 9 speaker locations. Very curious about what's under the center mounted speaker grill on top of the dash.Is there a subwoofer located somewhere in the car?

 

I have a C240, and has the subwoofer located in the trunk. I would say that is the best location for it, so take a look there. You could also adjust the sound to lowe and higher friquesncy and detect diffrent speaker location.
I hope this helped.
Thanks
KenZ