If luxury car manufacturers are to be believed, more speaker hardware is the best way to deliver a quality in-car audio experience. But a concept from Continental suggests ditching speakers altogether, and instead creates sound by vibrating some parts of the car's interior trim.
Continental likens the Ac2ated Sound concept to a string instrument. Rather than using a combination of tweeters, midrange speakers and subwoofers to deliver sound, the system relies on a set of compact actuators. They're made up of a magnet and coil, and operate in a very similar way to the coil you'd find on a conventional speaker.
Rather than connecting the actuators to an oscillating membrane, Continental uses them to excite existing pieces of interior trim and, in turn, create sound. The company says a few different parts of the cabin are suited to different frequencies – the A-pillar lends itself to higher frequencies, door linings have good proportions for creating medium frequencies and bigger areas like the roof lining or parcel shelf could play the role of subwoofer.
A similar approach to creating sound has been used in home audio like a TDK CD player and mini speakers from Damson, but it hasn't really made any real impact on the market. Although they can create a bigger sound by vibrating the surface to which they're attached, they're also heavily reliant on having the right surface nearby.
Combined, these existing elements of interior design could be used to replicate the "3D sound" effect some manufacturers are trying to deliver with optional sound systems that include between 10 and 20 speakers. Whereas these systems can weigh around 15 kg (33 lb) and require around 30 liters (1.05 cu.ft) of box volume, the Ac2ated Sound setup weighs just 1 kg (2.2 lb) and requires just 1 liter (0.035 cu.ft) to deliver the same effect.
Although it's a small thing, being able to remove speaker grilles and chunky subwoofers will make interior designers happy as well. It will be interesting to see if these benefits are enough to make manufacturers look seriously at cutting speakers in their cabins. Given many have partnerships with the likes of Burmeister and Naim, there might be bigger factors at play...
Continental will be demonstrating its concept sound system at the Frankfurt Motor Show.