Ford adds 'Active Sound Symposer' to Focus ST
For most economy car drivers, engine sounds range from a high tinny whine to a struggling lawnmower growl. Not so for drivers of the new Focus ST from Ford.
The Focus ST features technology called "sound tubes," which Ford calls its Sound Symposer. This was added to and perfected in the Mustang and is a common feature of today's sports car, no matter the manufacture.
Ford's next-generation of the tech is the Active Sound Symposer. The sound tube in the Symposer is just what it sounds like: a simple tube going from the engine compartment to the passenger cabin to convey engine sounds to enhance the driving experience. The latest version appearing in the Mustang is tuned to enhance sounds specifically in the 200 to 450-Hz frequencies - the throatier engine noises.
In the Focus ST, Ford has added an electronically-controlled valve that adjusts the amount of sound going through the tube. This allows the car to open or close the valve, thus controlling volume, so that when the driver is not actively engaging the engine (pressing the accelerator), the noise will be dampened, but when the driver is putting their foot down, the throaty engine sounds add a muscular feel to the drive.
Gearing also plays a role, with the lower gears having more sound enhancement than higher gears so that when the vehicle is cruising, the driver and passengers can enjoy a quiet ride.