Listening Helps Cadillac ATS Shape Interior Acoustics

[Bruce Nunnally]

Advanced sound deadening features make for a serene interior

DETROIT – The all-new Cadillac ATS sport sedan employs high-tech electronics to manage interior noise, following a simple piece of parental advice – “Listen!”

The new ATS contains three microphones inside the cabin that carefully monitor, and then adjust, interior sounds to create a proper environment for Cadillac’s sport sedan.

Active sound control technology proactively monitors the ATS’s cabin for unwanted noise and works to eliminate it. Alternately, passive sound-deadening in the form of covers, foams and other materials built into the vehicle absorb, block and eliminate vibrations, wind noise, and noise from passing cars.

Working together these technologies reduce the ATS’s overall sound levels by 3 decibels while idling, or the equivalent of making the vehicle nearly 50 percent quieter.

“Not all noise is unwanted, especially in a vehicle like ATS,” said vehicle performance engineer James Murphy. “While wind rush penetrating a closed window is undesirable, the driver does want to hear the vehicle respond with power during spirited driving.”

On the “active” front, Cadillac sound engineers worked with audio experts from Bose to create sound management technology that offsets low frequency “boom” noises between 40Hz and 180Hz.

“Imagine the feeling that goes through your chest at a rock or hip-hop concert when the bass hits you,” said Kent Ting, noise and vibration engineer. “That is similar to the ‘boom’ noises the Bose Active Sound Management system addresses by providing a cancelling noise signal.”

Three Bose microphones constantly monitor sound quality and deliver a counterbalance of noise through the vehicle’s speakers to cancel unwanted noises. The microphones are strategically placed above the interior door frame on the front driver and passenger and rear driver’s side to listen to the same sounds the occupant would hear.

“Passive” noise cancelling materials are woven into the vehicle in unassuming places, following the attention-to-detail-approach taken by ATS engineers. Some examples include:

• Roof – between the roof’s base sheet-metal and the interior lining, the ATS is treated with sound- deadening material that lessens noises like rain hitting the vehicle.
  
• Windshield and front side windows – Instead of traditional tempered glass, the ATS features acoustically laminated glass, which is made up of a sheet of sound-absorbing laminate sandwiched between two layers of glass. This limits the sound of wind rush and other traffic while driving.
  
• Rocker sections are injected with sound-absorbing foam that reduces noises made by the tires on varied road surfaces.
  
• Undercarriage – An underbody aero shield and wheelhouse covers serve a dual purpose of blocking road noise while driving, and trapping powertrain noise at idle.
  
• Powertrain – The ATS’s engine uses laminated steel, acoustic covers, isolation, and glove-fitted foam materials that contribute to reducing noise and vibrations under the hood. All of these materials are especially helpful in minimizing noise from the high pressure Spark Ignition Direct Injection system, which typically produces a “tick-tick-tick” diesel engine type of noise when the vehicle is idle.
  

Cadillac has been a leading luxury auto brand since 1902. In recent years, Cadillac has engineered a historic renaissance led by artful engineering and advanced technology.

[hjb981]

It makes me very happy that Cadillac continues to focus also on comfort, even after their "remake" to make cars with superb handling. A luxury car must be comfortable, and it is of paramount importance that its ride quality is good and that it offers a quiet cabin, both on good and bad roads.

[BodybyFisher]

Love this technology and the attention to detail and passenger comfort. One of the things that I noticed recently was how much sound penetrates windshields, even my 96 Deville permitted noise from vehicles in front on you. Cant wait till I see a review of it