the invention the front side comprises a plurality of controls in this respect one may find a volume control knob 1 a knob 2 for station tuning and push buttons 3 for example for selecting the frequency range such as fm mw lw or usw the front side of the car radio further has an aperture 4 located for example behind a grille 5 however the grille 5 is not necessary the aperture 4 has a rectangular shape and a width to height ratio of for example 3 1 if the width of the aperture 4 corresponds approximately to the diameter of the loud speaker 6 incorporated in the car radio cf fig2 it may be assumed that the height of the aperture 4 is about equal to 1 3 of the diameter of the loud speaker 6 the height of the aperture 4 however may also be taken smaller which is to say smaller than 1 3 of the diameter of the loud speaker 6 fig2 shows a cross sectional view of the car radio along the line a a in fig1 when installed in a facia or dashboard 10 of a motor car fig2 shows a loud speaker 6 accommodated in the housing 7 of the car radio the loud speaker is a cone loud speaker of the electrodynamic type these loud speakers are known per se and need no further explanation the loud speaker 6 acoustically cooperates with a channel 8 which is also accommodated in the housing of the car radio one end of the channel opens into the aperture 4 at the front side of the car radio mechanical vibrations of the diaphragm 9 of the converter 6 are converted into acoustic waves reaching the motor.