Tunable Tailpipe

J.J. Eberspaecher GmbH & Co. KG says it hopes to have a unique system on the market by 2009 that will allow drivers to dial-in the exhaust tone of their choice for their vehicle.

The German-based supplier already has a prototype tuned-exhaust system installed in an Audi A4 2.0L Turbo that can produce up to five different tones, a company official tells Ward's.

The acoustical technology also includes an active silence system, which cancels exhaust noise by using a microphone and speaker embedded in the muffler that produce “anti-noise,” effectively canceling out most exhaust sounds.

By suppressing or amplifying the exhaust noise produced during the firing of a vehicle's cylinders, the tuned system can make a 4-cyl. car sound like a V-8 model or vice versa, depending on the driver's preference.

“If you look at BMW (AG), we have a different sound on the convertible, a different sound on the hatchback, the station wagon and for just the normal vehicle,” Mathias Keck, Eberspaecher vice president-research and development global exhaust technology, says of his company's largest OE customer.

“We already have that, but every time we have different hardware inside. With this (newest) system, we could have one exhaust system and create different sounds with the speaker and electronics.”

Eberspaecher recently patented its microphone and speaker tuning system, which can withstand the extreme heat of a vehicle's exhaust, Keck says, adding the Audi outfitted with the sound system has undergone more than 12,427 miles (20,000 km) of testing.

The supplier experimented with a similar tuned-exhaust system 15 years ago with less-than-stellar results, he says, noting it produced “terrible sound.” But engineers revisited the concept four years ago, this time with better results.

“Customized active sound design and an active silent system are an old dream of sound engineers,” Keck says.

Eberspaecher has demonstrated the system to several European auto makers.

The company, which in addition to conventional exhaust systems also produces catalytic converters and mufflers for gasoline engines, as well as particulate filters and catalytic converters for diesel engines, has a North American manufacturing subsidiary located in Brighton, MI, 65 miles (105 km) west of Detroit.

A 2005 expansion doubled the company's $10 million investment in the 46,000-sq.-ft. (4,274-sq.-m) facility, with 58,600 sq.-ft. (5,444 sq.-m) of additional manufacturing space and 2,500 sq.-ft. (232 sq.-m) of additional office space.

About 75 employees, mostly production workers and several engineering, office and logistics personnel, were added to the approximately 125 person-strong workforce employed at the plant.

One of the first North American vehicles to feature Eberspaecher's tuned exhaust system was the Chrysler 300, Keck says, adding Chrysler Group was pleased with the results.

Keck says some auto makers still are deciding whether such an exhaust-tune system has merit. “Some are not sure if customers would like (the system) if they knew the sound was coming out of a speaker.”

However, one European auto maker, who Keck declines to reveal, plans to put the system into production by 2009.

Keck says the exhaust tuning most likely will appear on a “high-end niche” vehicle, as the cost compared with a standard exhaust system is substantial. He declines to disclose what the difference would be.

Eberspaecher also could peddle its system to the aftermarket, where new technologies often are adopted before making their way to mainstream production, he says.

Eberspaecher's tuned exhaust system builds on a current trend that sees a growing number of auto makers looking for distinctive exhaust tones in order to differentiate their product in an increasingly segmented market, Keck says.

A U.S. survey conducted by J.D. Power & Associates supports Keck's claim. Owners surveyed in the 2001-2005 Automotive Performance, Execution and Layout Study expressed increased satisfaction with the sound of their vehicle's exhaust tone, both at idle and full throttle.

Yet, the study also revealed the importance of the exhaust sound to car buyers had declined.