REPORT: High-tech muffler speakers make diesel engine sound sporty, cut noise levels by 20 dB

An exhaust-system and heating-solution supplier has reportedly engineered an electronic way to modify the sound coming from a vehicle's tailpipe. The company, Eberspächer, claims the innovation can make diesel-powered vehicles sound sportier and add an audible sound track to near-silent electric vehicles.
While mechanical devices – including flaps, dampers, or acoustic materials – have become commonplace in modern exhaust systems, this unique technology utilizes a dedicated electronic control unit (ECU) to emit sound waves to counter much of the unwanted frequencies (similar to the process of noise-canceling headphones). Of course, the same speaker technology that generates the "white noise" may be used to create new exhaust notes.
The obvious benefits are more appealing exhaust tunes, but it doesn't just stop there. This sound-deadening technology allows automakers to reduced the size of the existing mufflers (saving both weight and cost), and it may add some needed noise to the electric vehicles navigating our roads and highways.
[Source: SAE International]












Reader Comments (Page 1 of 1)
Mark H. 6:07PM (9/11/2009)
Hmm, I had been hoping to make my car sound like one of those giant diesel trucks! Complete with a refillable can of soot that would belch a big black fart every time I accelerated.
Reply
vkchu 7:47PM (9/11/2009)
ill take one in tubi style, pls.
Jimbo 6:07PM (9/11/2009)
I don't think sound is the major issue when it comes to consumer acceptance of diesel. Modern diesels (with the exception of those in HD trucks) are very quiet. The big problem is lack of choice. If you want an affordable diesel, your only choice is the VW Jetta (and soon the Golf). That's it.
Reply
cool_ozzyfromkalush 8:37PM (9/11/2009)
U got it a bit wrong there, I agree that HERE in North America, diesel is not exactly popular but in Europe... Its very easy to spot a deisel in a traffic jam when you heard enough of them, and 20 db is quite a lot. But yea, I WANT MORE DIESEL around here, it would make so much easier picking your first car, I bought a 01 Mustang GT and a local Shell. :D
Dondonel 6:09PM (9/11/2009)
Right, this is what diesel needs, how about curing that angry lawnmower noise?
Look at this guy, he's revving his 'sportwagon', so hopeless/hilarious:
http://www.youtube.com/watch?v=lrL6cTJub0s&feature=related
Reply
Jimbo 6:15PM (9/11/2009)
That's an older version of the TDI. Here are videos of the new TDI. It is plenty quiet with the hood closed and silent from inside the car.
http://www.youtube.com/watch?v=NpDJ2yaI7F4&NR=1
http://www.youtube.com/watch?v=luL353r8fcg&NR=1
Dondonel 6:12AM (9/12/2009)
Jimbo, I can't decide which one sounds the worst, they're terrible.
Benfolio 6:12PM (9/11/2009)
I hope the sound it emits is user programmable. I want my electric car to sound like George Jetsons'. EBEBBEBEBEBEBEBEBEBEBEBEBEBBEBEBBE!
Reply
Julius 6:38PM (9/11/2009)
Just curious what the weight differential is between a muffler and this sound system setup with dedicated ECU. Also, I wonder how much energy draw there is to cancel the sound waves involved.
Reply
Jim 6:38PM (9/11/2009)
"This sound-deadening technology allows automakers to reduced the size of the existing mufflers (saving both weight and cost)"
I think the transducers and support electronics to power these things would way more than wipe out the cost savings from not needing conventional mufflers.
Reply
jerjozwik 7:10PM (9/11/2009)
loud pipes save lives!
Reply
Eric Bandholz 7:22PM (9/11/2009)
This article would be nicely complemented with a video or at least an mp3.
Reply
Rich 7:34PM (9/11/2009)
"add needed noise"
How about "honk"?
Reply
Stratatak7 7:54PM (9/11/2009)
Ah the next generation in rice technology :p
Reply
Fyrewerx 8:50PM (9/11/2009)
Walker Muffler (right here in the U.S.A.) did this with piezo-electrics years ago. They didn't make any diesels sound like sports cars, but they used the same technology to cancel out the exhaust note without needing baffles and packing to stiffle exhaust flow.
Reply
Aron 10:03PM (9/11/2009)
I'm having Deja Vu. A decade ago I worked for Walker Electronic Silencing (a division of Tenneco) which developed OEM systems for the Viper, Corvette, Prowler and A6.
http://www.nytimes.com/1999/03/18/technology/ah-the-sounds-of-almost-silence.html
The main problem? The speaker enclosures on the Viper would melt during hot testing in Death Valley. Ironically the transducers themselves actually survived the 1600F misfire testing.
The main benefit the automakers were looking for at the time was not reduced cost or weight, but to allow an increase in power from the straight pipe (no muffler) and still meet federal sound limits.
Reply
Keef 2:50AM (9/12/2009)
Yeah, straight pipes! That sounds like an awesome American innovation, and I love it. This new German guy is an idiot though. All he cares about is making diesels actually sound cool, like in that Volkswagen commercial. In terms of sound, I'd rather have a hybrid's whoosh as opposed to a diesel's clackety-clackety-brrghghhgrrr--wwssssssss-brrrrghhghghgh....
Nuieve 9:09PM (9/11/2009)
High-tech muffler on a car with mismatched tires FTMFW!
Reply
Keef 2:44AM (9/12/2009)
This new system makes it possible to get rid of mufflers, saving weight and money, eh?
Hmm.
Well, seeing as it costs approximately $3 to make a muffler, I'm going to call that a load of bollocks. Those big things in the picture up there are just about as big as mufflers too, and that means they probably weigh about the same. And they have their own computer!
So what we have here is an expensive, stupid muffler, basically, that makes fake, stupid noises. You've got to be kidding me if you say someone got paid to come up with that idea.
Reply
dukeisduke 1:41PM (9/12/2009)
So the Prius can emit the sound of unicorn farts?
Reply