Car audio systems reaching new heights music to motorists' ears

by Jim KerrAuto Tech . Dec 02 2016
Revel

Revel

Whether it be rock ’n’ roll, rap, classical, country or audio books, everyone has their own favourite type of entertainment — and we spend hundreds of hours a year in our vehicles listening to them. The car radio has undergone a tremendous change, especially in the past few years, and some of these systems rival the best professionally installed home entertainment systems.

Two new audio systems come to mind. Lincoln’s Revel Ultima sound system in the 2017 Continental and Cadillac’s Bose Panaray audio system in the 2016 Cadillac CTS.

Concert halls are designed so sound travels to all parts of the hall, while reducing echoes and extraneous noise from the outside. To accomplish this setting in a vehicle is difficult but not impossible.

First, you need a quiet interior. From suspension design to body-panel damping materials, everything contributes to the design of interior sound levels.

Both Lincoln and Cadillac use active noise control systems that “listen” to repetitive interior noise and use opposing sound waves generated from the audio system to cancel these sound waves.

These systems work even when the audio system is turned off.

Lincoln is also installing Soundscreen laminated glass instead of tempered glass in all four door windows to reduce noise transmission through the glass to the interior. Cadillac’s CTS uses high-strength steel in the floor pan rather than aluminum panels because there is less noise transfer through steel.

Multiple speakers are required have sound travel to all parts of the interior. To do this, the Lincoln Continental’s Revel Ultima system uses 19 speakers, while the CTS’s Bose Panaray system uses 34 speakers.

In both systems some speakers are very small tweeters that produce high-frequency sounds, some are quite large to produce the very low-frequency sounds and others produce the mid-range sounds. That full spectrum of sound waves transmitted to your ears gives you the fullness feeling of being in a concert hall.

Placement and the type of speakers received intense scrutiny. In the Lincoln, the Harmon engineers (Revel is a trademark of Harmon International Industries) looked at interior finishes, shapes and spaces to determine the optimum speaker placement.

Just like in a concert hall, the reflection of sound off different surface materials were considered and Harmon worked in conjunction with Lincoln’s interior designers to produce the best results. The result is that every seating position in the car receives equal quality of sound.

You might think the 34 speakers of the Bose Panaray system in the Cadillac CTS would sound better, but there is the law of diminishing returns. Each additional speaker does add to the evenness of the sound production but not as much as the first ones. Bose engineers analyzed every possible speaker location in the vehicle and place speakers in the A-pillars, footwells, headrests, doors, dash and rear passenger compartment.

The Panaray system uses multiple speakers in each location with each at different projection angles to fill the interior with sound in all directions. The headrest speakers use unique technology with their Truespace 2 digital sound processing to make the sound appear to come from a place further away rather than directly behind your head.

The “head unit” is the control centre of the system.

The entertainment controls on the Lincoln include their Quantum Logic software that decompresses music for that natural live music sound. Most recorded music is saved in a compressed format.

This means the music is digitally sampled and some samples are removed so you can store more music in the same storage space, but some quality is lost. The Quantum Logic software fills in the deleted samples for better sound quality.

Driver audio controls include three modes: On Stage, Stereo and Audience, so even though there are the typical fade and balance controls, you don’t really need to set them.

The Bose system uses CenterPoint 3 software to split two-channel stereo into multiple channels and directs these channels to the 34 speakers. Similar to the Revel system there are sound modes for Driver, CenterPoint, Rear and Normal, as well as manual settings.

Both of these vehicles have sound systems that rival the best home audio system, with a clarity and fullness that make you feel like you are at a live performance.

We spend a lot of time in our automobiles. Why not enjoy it fully?

james.kerr@sasktel.net