Harmon Kardon Sub Grille
 

Good morning all,Does anyone know what diameter the sub grille on the rear parcel shelf is? How it fits on the parcel shelf?And will the cut out i presume is needed in the parcel shelf already marked or is guess time?.Reason for these questions is i have fitted a 10" active sub in the boot and it isnt very loud i have a seperate sub volume on the stereo but if i turn it up things(boot floor,Door cards etc start to vibrate.The boot floor has been upgraded to 12mm marine ply covered in close cell foam.My rear seat didnt have the ski hatch thing so i cut out where it should be and travel with the arm rest down.I have also adjusted the cutoff frequency of the sub(on the sub)and also the volume(on the sub) then matched things on the Stereo.Also fitted a power cap, i was hoping the hole in the parcel shelf would help with the sub loudness.

Hope someone can help

Cheers Chas