Fixing the Other Car Audio Problem

Carmakers have a problem. OK, I’m sure they have a lot of problems, but as this one has to do with sound, it’s relevant to us here at S+V.

As cars have gotten quieter, and as turbocharging finds its way onto more vehicles, we’re losing the sonorous soundtrack of the engines themselves.

So the engineering wizards are using technology to combat the progression of... technology?

If you drive a Camry, the lack of engine sounds in your beige automopliance is a good thing. Why disturb your sleepdriving?

For those of us actually interested in cars, the engine sound is a key component of the overall experience. From the clacky patter of a flat-four, to the thunderous gurgle of a V8, sound gives a car character. Unfortunately, this is largely at odds with the more popular goals in car design: gas mileage and the reduction of NVH (Noise, Vibration, Harshness).

A number of companies have developed odd “fixes” using various technologies to give the driver more aural feedback.

When I recently reviewed the Porsche Panamera Turbo S, I found the lack of V8 engine noise disappointing, especially from a company famous for the sound of their luscious flat-6 engines. Partly this was due to the quiet cabin, but it was also due to the muted sounds from the twin-turbocharged engine. Turbochargers, little turbines that use exhaust gasses to shove more air into an engine’s cylinders, suppress some of the lovely noises caused by the rhythmic expulsions of previously exploded air and gas. Knowing this would be a concern, Porsche’s solution was a button that opens valves in the exhaust, making it louder. Was it louder? Sure. Was it memorable? Not so much.

Ford has gone in a slightly different direction. With the upcoming Focus ST, they’re using what they call an Active Sound Symposer. It’s a “composite ‘paddle’ that vibrates with intake air pulses.” Well, vibrations are sound, so it’s transmitting the sound of the engine into the cabin. However, it does so only at certain frequencies, those between 200 and 450 Hz. In addition, it has an electronically controlled valve that opens and closes depending on engine speed and go pedal position. In other words, it’s loud when you want it loud, and quiet when you want it quiet (like on the highway).

You can hear for yourself how it sounds. It’s certainly a sound more fitting for a sporty car like the ST, more so than for the calmer tuning of the base Focus. Does it sound as good as my 10-year-old SVT? Not really, but I’m rather biased.

Other companies are trying other methods. BMW’s “Active Sound Design” augments engine sound using...the car’s speakers. I have so many questions. Is it an MP3? Can you hear compression of the compressions? Can I get it to sound like a different engine? Even better, why have a V8 at all when you can just make any old engine sound like one? Seriously, this like giving polyester a fancy name and charging a bunch of money for it.

Bottom Line

We’re likely to see more and more of this in the future. Even the fabled 911 Carrera will feature “sound enhancement,” thankfully of the mechanical variety.

As an audiophile and someone who writes and reviews audio, I have to say I’m highly skeptical of any electronic audio enhancement of the car’s sound. Not just for the inherent lameness of the idea, but also the unlikely ability of any such system to produce anything approaching realistic fidelity.

That said, and despite being a car fanatic, the push towards more efficient engines is unquestionably a good thing, even if the unfortunate cost is less charming engine noises (though not always). Adding excessive amounts of heavy sound deadening materials just for 1 dB less noise, well, that’s a conversation better suited for another time (and place).

But come on, engine sound through the car’s speakers? Give me a...brake.