These are some frequency response measurements of the 2012 Mercedes-Benz GL-Class’s optional Harman Kardon in-car sound system. While its frequency response is far from neutral, this 12-speaker sound system is quite enjoyable to the ear. The sub-bass boost compensates for the engine noise, and the treble roll-off makes a non-fatiguing sound, which is especially appreciable for long road trips.
Driver Seat
Front Passenger Seat
Fortunately, setting the bass level to -10 in the sound settings makes the low bass less exaggerated and the whole bass region flatter.
Normally, you would expect surround sound effects to adulterate the frequency response, but this is not the case with Logic 7, which significantly improves the soundstage while keeping the original frequency response intact.
Logic 7 does not add reverb.
Rear Seats
The rear seat passengers will miss some lower mids.
Overall, the Harman Kardon sound system in the 2012 GL-Class delivers good performance in terms of midrange neutrality, soundstage and spatial consistency. I strongly recommend keeping Logic 7 on and setting bass to -10.
