Beware of false information.
There are 2 misconceptions about surround sound in cars that need attention if there is any chance of this wonderful concept to ever become widely accepted in this industry.
1. Misconception #1 – Multichannel surround sound in the car is only worthwhile if you have specially made recordings. DVD movies and audio qualify. Because DVD Audio is a dead format there is no good reason to build an aftermarket surround system.
2. Misconception #2 – If you decide to add surround sound to your car any 5.1 DSP will get the job done.
These 2 points go hand in hand. Really effective multichannel audio reproduction in the car needs a DSP which creates a discreet center signal and rear speaker signals which add ambiance and increase the illusion that you’re listening in a bigger space than the car’s interior. The center signal and the way the DSP steers sounds is critical. Today this requires on-chip software which has licensing attached. The associated license costs are one reason proper multichannel DSP options are sparse today. Lack of understanding of how this technology works and lack of understanding of how to sell, install and tune these systems is another major hurdle.
I will use the term “multichannel” in place of “surround sound” at times.
Stereo vs Surround Sound
Stereo has been around since before most of us were born. Multichannel surround sound in the cinema came about in the 1940s; multichannel in the car is much newer and is the focus of this post. Before we can talk about multichannel we have to have a basic understanding of how this differs from the stereo sound that we all have grown up around.
The source is Between Monophonic, Stereophonic and Surround Sound.
Stereo or Stereophonic sound is created by two independent audio channels or speakers and provides a sense of directionality because sounds can be heard from different directions.
Multichannel sound, also known as surround sound, is created by at least four and up to seven independent audio channels or speakers placed in front of and behind the listener that surrounds the listener in sound. Multichannel sound can be enjoyed on DVD music discs, DVD movies and some CDs. Multichannel sound began in the 1970s with the introduction of Quadraphonic sound, also known as Quad. Multichannel sound is also known as 5.1, 6.1 or 7.1 channel sound.
Multichannel Music in Your Car
Multichannel sound reproduction is found in many premium factory sound systems, or it can be added with a DSP. The scope of this discussion is the way multichannel in the car is useful for getting better sound for 2 or more seats, not just 1 seat at a time. Some factory premium systems have a setting for the listening position, and if you’ve tried this you have probably heard a significant change in the sound. Some aftermarket multichannel DSPs do a good job of this; others fall short. Aftermarket head unit manufacturers have tried 5.1 surround sound, although a “listening position” setting is much more common.
Improving the sound of music for more than just the driver’s seat requires 2 front left and right speakers, a center speaker, 2 rear left and right speakers, and a subwoofer. Some form of multichannel digital signal processing is required, and the DSP needs a way to “upmix” 2 channel audio into 5.1 “better stereo”.
If you have questions about multichannel audio or anything else on the topic of car audio, feel free to contact me.