Whether it’s Bach or the Beatles, blasting music out of a car stereo’s speakers is one of the unalloyed joys of summer driving. So one may well wonder, if two channels of music are so great, wouldn’t more channels sound even better?
For decades, cinemagoers have enjoyed multi-channel surround sound in theaters, and those with the inclination and budget have been able to recreate the sonic effect at home with multi-channel sound systems. But in spite of efforts by music and consumer electronics companies, music recorded in multiple channels has never caught on, partly due to the expense of playback equipment, the lack of standards, the paucity of multi-channel recordings, and, quite frankly, the hassle of wiring up 6 or more speakers in a room.
The built-in sound systems in today’s cars, on other hand, usually come with multiple speakers, front and rear, making them potentially ideal candidates for playing multi-channel music. With multiple channels, Bjork’s soaring vocals sound as if you are sitting on stage surrounded by her percussionists. Or Ron Carter’s bubbling bass lines take on a live sound as if you are seated in the front row at Carnegie Hall. Unfortunately, you can’t just pop a multi-channel disc in your dash to recreate such sonic effects. The reason: having multiple speakers in your car isn’t the same as having multiple channels.
For true—so-called discrete—multi-channel sound a CD or DVD player has to be able to decode and separate 6 or more audio signals from a disc, and then an amplifier has to steer the individual signals out to the speakers (versus “matrix” surround sound systems that try to recreate the multi-channel effect using just two channels). Compounding the problem is the fact that there are several competing multi-channel formats, including Super Audio CD (SACD) and DVD Audio on music discs, and Dolby Digital and DTS on movie discs. Most CD and DVD players cannot play these various formats and some play the discs in mixed down, two-channel mode. Furthermore, some formats adhere to a so-called 5.1-channel format (the “point one” referring to a low-frequency channel often handled by a subwoofer)—others bump the channels up to 7.1. So sorting through the options and looking for the right disc format to match your player can give even ardent music fans a headache.Sony, for example, is one of the companies that developed Super Audio CD, so its $279 MEX-DV2000 supports SACD, as well as DTS and Dolby Digital--but not DVD Audio. Conversely, Pioneer Electronics’ $2,200 AVH-P7800DVD entertainment system can handle DVD Audio discs in 5.1 surround sound mode, as well as Dolby Digital and DTS—but not SACD. And there are models, such as Alpine’s $650 DVA-9861 disc player, which can handle Dolby Digital and DTS multi-channel formats, but doesn’t support SACD and mixes down DVA Audio into two channels.
For those adventurous—or foolhardy—enough to try installing such a system in their own car, there are also the issues of wiring, amplification and, most challenging, the number and placement of speakers. Players need to be connected to multi-channel amplifiers, such as Alpine’s $300 MRA-F350, often using optical cables, which are needed to handle the additional data traffic required by higher resolution DVD Audio channels. And many 5.1-channel systems actually use10 or more different speakers, which have to be carefully placed, matched precisely with frequency crossovers, and then “tuned” so that they don’t generate added distortion, such as standing waves. Getting all of these elements just right within the confines of the car’s cabin and dealing with the interior glass, which further compromises audio quality by reflecting sound, is an audio engineer’s nightmare.
“There’s also the challenge that the driver and the passengers are not sitting in the center ‘sweet spot’,” which is ideal for listening to surround sound recordings, according to Caroline Johansson, senior sales manager at Dolby Laboratories. Listeners tend to hear the speaker that’s closest to them.
“So we do time correction and equalization to adjust the arrival times of the sound from each individual speaker,” explains Scott Neill, Alpine's product education and training administrator. It’s a complex task made possible thanks to digital signal processors in such entertainment systems—but it’s still best left to professionals.
Consequently, it’s simpler to choose a factory-installed multi-channel system when you check off the options on a new vehicle. Sound system manufacturers spend months customizing their systems to suit particular car interiors, and then spend additional weeks tweaking and tuning the systems to optimize the sound quality in selected models. But while many luxury car brands now offer surround sound options, the industry hasn’t settled on a de facto multi-channel standard—although the trend seems to be favoring DVD Audio for multi-channel music.
Mercedes Benz, for example, makes it easy for S-Class buyers by including Harman Kardon’s Logic 7 system as standard equipment. The Logic 7 package boasts an array of 14 speakers and can play Dolby Digital, DTS, and DVD Audio—but not SACD. Also offering DVD Audio support as an option are models like the 2007 Acura MDX with a $3,500 technology package. Cadillac offers an optional $1,000 Bose sound system on its 2008 CTS (starting price, $32,990) that plays DVD Audio in full surround and includes a 40-gigabyte hard drive for storing music files.
But what do you do with you do with your SACD discs? There is one universal disc player capable of playing nearly every acronym-laden format yet introduced, the new Bose Media System. Bose’s package supports both SACD and DVD Audio, and automatically plays music in the highest number of audio channels available on the disc. The system includes Bluetooth for hands-free calling, a navigation package, and, of course, the requisite iPod connection. Unfortunately, the ultimate disc player comes attached to the ultimate car: the 12-cyclinder Ferrari 612 Scaglietti, with a base “if you have to ask, etc.” price of over $260,000.
Will such universal support for multi-channel sound eventually become affordable for those of us with more domestic tastes? It depends on whom you ask.
Companies behind brands including Jensen and Panasonic say there is isn’t much multi-channel music available, and the discs that are in stores are more expensive than standard CDs. Furthermore, there isn’t much consumer demand.
“People are still in the two-channel mode when they think of music,” says Alpine’s Neill. “They associate surround sound with movies, and you can’t watch a movie while you’re driving.”
On the other hand, movies may be precisely what drives multi-channel sound adoption in cars in the future as more vehicles feature rear-seat entertainment systems with Dolby Digital sound. “Five or 6 years ago, there was hardly any mention of surround sound in cars,” says Dolby’s Johansson, “but now it’s taking off as people grow to love DVD in their cars.”
But whether one multi-channel format or another ultimately wins out in the car, one thing is for certain: more channels do sound better than two. J-Q.com