Let’s look at how the system is laid out.
How Revel Works
The Revel system in the MKX is available in two versions: a 13-speaker version and a 19-speaker (although 20-channel) version. The core of the system is an array with an 80 mm midrange and a 25 mm tweeter, which you can see pictured below. (You can barely see the midrange driver through the grille.) It’s designed in much the same way as the Performa3 speakers, with a waveguide on the tweeter to smooth the transition between the two drivers. The two drivers are positioned closely together to function more like a single sound source. Even the crossover points and slopes are similar to the ones used in the home speakers. (In the car, the crossovers are done in digital signal processing, not with passive components such as capacitors and inductors.) Each of the four passenger doors has a 170 mm midrange woofer, and there’s a tweeter in each passenger door. A rear-mounted subwoofer provides the bass. The 19-speaker system, which carries the Ultima designation used on Revel’s top speakers, includes the following:
A full midrange/tweeter array in each passenger door. Two midrange/tweeter arrays in the rear. A dual-coil subwoofer that can take advantage of an extra amplifier channel.
In all, the 19-speaker system has 20 amplifier channels. The amplifier is a hybrid design, with traditional Class AB amps for the tweeters and high-efficiency Class D amps for the other drivers. This is intended to deliver the best mix of efficiency, compactness, and sound quality. It mounts in the left-rear corner of the car, opposite the subwoofer.
The Sound
We were happy to hear how much of the sound quality of our home system seemed to carry through into the car systems. We couldn’t hear the transitions between the drivers. As with home speakers, the colorations are minor. The system sounds remarkably neutral and engaging—unlike most car audio systems, which can sound somewhat dull. Just as important is the system’s sound staging, which doesn’t sound like that of other car systems. There is a broad expanse of sound stretching across the dashboard. It sounds almost as if there are virtual speakers atop the dashboard, placed about one foot in from either side, similar to a home system. It’s difficult to localize the side-panel midrange/tweeter arrays. When listening to an EDM tune with massive, ultra-dynamic bass cranked to full blast, we didn’t hear any distortion, nor did the sound grow thin or the woofer obnoxiously boomy. It sounded much the same, just a lot louder. This is due to advanced limiter circuits. The speakers run 35-volt power supply rails into 4-ohm loads. “Typically, the audio people get about a week to tune a car,” Alan Norton, Manager of Global Entertainment Systems for Ford Motor Company (Lincoln’s corporate parent), told us. “With this one, Harman had the car for several months.” The company set up a Revel speaker system in an adjacent room so that during the tuning process, engineers and trained listeners could hear the Revel system. Then, they could walk next door and hear the Revel system in the car. It should be no surprise that the car system sounds so much like the home speakers.
The Technologies
That’s in stereo mode. The Revel/Lincoln systems are the first to feature Harman’s QuantumLogic Surround, or QLS, technology. QLS analyzes the incoming signal, digitally separates the instruments, then steers instruments into the speakers in the surround array. Conventional matrix surround decoders such as Dolby Pro Logic II and Lexicon Logic7 (which QLS will replace) only analyze the differences in level and phase between the left and right channels. These decoders steer sounds into the surround channels without much regard for frequency content. We’re hypersensitive to the steering and phase artifacts that most matrix decoders produce. We were amazed to hear not even a hint of them in QLS. It sounded like actual 5.1 or 7.1 audio. “What I like about QLS is that it’s not adding anything,” Ford’s Norton said. “You can add all the signals back together, and you get the exact same stereo signal you started with.” Two QLS modes are included:
Audience provides a fairly subtle, ambient surround effect.Onstage steers sounds more aggressively into the rear channels.
There’s a straight stereo mode, too. The factory setting defaults to Audience mode, but you might enjoy the dramatic, wraparound effect of the Onstage mode. One cool thing about the system is that there’s no muting or clicking when you switch modes. It just fades imperceptibly from one mode to the next. Both Revel systems have Harman’s Clari-Fi system running full-time. Clari-Fi is designed to restore high-frequency content to audio files compressed using MP3 and other codecs. The more compressed the music is, the greater the effect Clari-Fi has. On low-bitrate satellite radio signals, Clari-Fi does a lot. When you play CDs, it does nothing. We got a brief Clari-Fi demo at Harman’s Novi facility, and it seems to work pretty much as advertised. The Revel system sounds like a different kind of car audio system. Give it a listen and see if you agree.
