Car Speaker Size

Measurement speakers ( speakers, jargon " unit " ) to calculate the size of the effective vibration radius. Ie not pressed into the outer edge of the cone fixed apron diameter count , it is customary for the speaker diameter in inches .
Most people use mostly Car Speaker metric ruler , measure how many centimeters the cone diameter , divided by 2.54 ( 2.54 centimeters equals one inch ) , is an inch.
4 -inch speaker : the screw holes on the angular distance is 11.5 cm , adjacent pitch 8 cm , horn diameter is 10 cm ;
5-inch speaker : the screw holes on the angular distance is 13.5 cm , adjacent pitch 9.5 cm , diameter 13 cm ;
6.5 -inch speaker : the screw holes on the angular distance is 15.5 cm , adjacent pitch 11 cm , diameter 16.5 cm ;
4X6 inch screw holes adjacent bookshelf speaker distance is 12.3 cm and 7.3 cm ;
6X9 inch screw holes adjacent distance is 16.5 cm , respectively, and 11 cm .