Ask any car guy (or gal) about what can make or break the perceived quality of a perfect car — and they’ll likely tell you that sound (or noise) can play a huge role in the highly subjective assessment. Managing noises and sounds that a driver (and the vehicle’s other occupants) may want to hear (such as the engine note) and others that they don’t (such as wind noise or the drone of an exhaust system) has become an essential element of vehicle development, and a tell-tale sign of an automaker’s engineering prowess as appreciated by consumers.
“Not all noise is unwanted, especially in a vehicle like ATS,” said vehicle performance engineer James Murphy. To that end, Cadillac’s compact-luxury performance sedan — the ATS — makes use of active and passive methods to manage cabin sound, including high-tech electronics and sound-deadening materials.
On the active noise cancellation side of the equation, the ATS utilizes three Bose microphones inside the cabin that monitor and adjust interior sounds to create an optimal driving environment for the occupants of the sport sedan. The three mics use sound control technology co-developed with Bose to proactively monitor the ATS’ cabin for unwanted low frequency “boom” noises happening between 40Hz and 180Hz, and then neutralize it by offsetting the noise with a counterbalance of sound through the car’s speakers. The microphones are strategically placed above the interior door frame on the front driver and passenger sides, as well as the rear driver’s side, to listen to the same sounds the occupant would hear.
When it comes to passive noise cancellation, the ATS features sound deadening materials (such as covers and foams, among others) woven into the vehicle in unassuming areas. These materials work to absorb and block noise from passing cars along with eliminating vibrations, and speak to the overall attention to detail by engineers. The areas of the ATS containing sound deadening materials 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.
Working in tandem, the active and passive noise-canceling systems reduce sound levels by three decibels — which is the equivalent a car that’s 50 percent quieter.
Given that most initial ATS buyers traded in a vehicle from another make, it seems that consumers are taking notice of the high level of detail invested in the ATS by Cadillac. Now, how about that eight-speed transmission?