McLaren has filed a patent with the European Patent Office that could spell the end of fake engine noise. The Woking-based manufacturer of visceral hypercars details a sound manipulation device, but not in the common fashion; this is purely hardware-based and has nothing to do with pumping artificial sounds into the cabin through speakers. Instead, the device, which can be used for both induction and exhaust amplification, essentially captures and magnifies the natural sounds of a combustion engine.
How It Works
Like a Porsche patent we discovered the idea is structured around routing natural engine sounds from the bay to the cabin. However, McLaren’s development can direct the sounds externally, too. The patent specifically notes that it is important for a high-performance car to sound like such, and losing an emotive sound may also mean losing the attention of onlookers and occupants alike.
The device, which can be placed anywhere upstream of the intake or downstream of the exhaust, comprises a first membrane, or chamber, potentially with flexible walls. This may be made of one or more thin sheets of metal, which may be corrugated. Within its walls are bellows, and these act as a pneumatic seal between the first and second membranes, keeping exhaust gases out of the latter.
Transmitting the sonic vibrations is a suspension system, which can be a rod, a spring, or a volume of compressed air. As this moves, the conical- or dome-shaped second membrane/chamber magnifies the resonance; in fact, it’s called a radiator membrane since the sound outlet is radial.
This outlet can be made of paper, plastic, or metal, so long as it has partial rigidity to prevent uncontrolled vibrations and low mass to minimise the starting force required to move the membrane.
If the right balance is struck, this promises acoustic efficiency high enough to recoup losses from the first membrane, which logically dampens some sound as it must be strong enough to withstand the temperatures and pressures of an induction/exhaust system.
As a side note, McLaren also notes planetary bushings for this sound manipulation device to keep the sound as pure as possible, even when riding over bumps or kerbs, although there may be benefits to such feedback, too.
Why It Matters
A device like this has the potential to drastically alter the quality of the induction and exhaust noises that are channelled to the cabin under acceleration and deceleration. Additionally, they can significantly improve the tone and timbre of the sounds that are heard outside the car without polluting the atmosphere with gasoline particulate filter/catalytic converter bypass systems. For the muffled turbocharged hypercar, this is great news. But McLaren points out that a device like this can be used on a combustion engine of any sort, regardless of layout, piston count, or application, specifically noting that a range extender could benefit, too. Wherever it may someday find a home, this sort of innovation underscores the need for emotion in performance cars, emotion that cannot come from sheer numbers and statistics.
