Take superb 5.1-channel home theater sound, and add a surround speaker. You've got 6.1!

If you remember the days of large, single-cabinet radio-and-turntable devices (my grandmother's was the size of a bureau, and highly polished, with a wicker front grille), then you remember what it was like when stereo was introduced. Suddenly, sound was so much more enveloping and detailed!

Clearer still in my memory was when I first connected my TV to my stereo system and sent sound out through my bookshelf speakers, instead of the little plastic grille on the front of my set. Wow. Dialogue was much crisper, and the music — especially the frenetic little "Simpsons" theme by Danny Elfman — had so much more impact. Suddenly, friends wanted to watch rented movies at my place.

Fast-forward 8 years. Instead of a VCR, I use a DVD player for all my movie watching. My TV's screen size is significantly larger than it was back then. And I have a full-fledged 5.1-channel surround sound system! My home theater is finally complete.

Or is it?

A few years ago, 5.1-channel sound was the standard. Sure, you could get a receiver that did 6.1 sound, but it cost a good bit more. Plus, since most traditional speakers were sold in pairs, it was hard to get a speaker system to go with it; salespeople looked at you funny when you marched in and announced you want a subwoofer, a center channel speaker, and five bookshelf speakers. Besides, very few movies were encoded for 6.1 surround.

Today, everything's changed. Let's take a look at what goes into 5.1-channel and 6.1-channel surround sound, and see why this change has come about. Along the way, I'll answer some of the most common questions people ask about 6.1 surround.

The basics of multichannel sound
In some ways, surround sound is kind of like barbecuing. If you're trying to grill some burgers, cramming the patties over one smoldering cinder is going to mean sloooow cooking time, and pretty uneven cooking. On the other hand, a superior gas grill, with 40,000 BTU of flamepower, and gas jets all over, is the barbecuer's best friend: food cooks evenly and quickly, and it's much easier to fine-tune the grilling.

Surround sound works on a similar principle. The more speakers you have dispersed around you, the more enveloping the effect of the sound.

Of course, multichannel sound is more precise than barbecue! When you're playing a movie with a specially formatted multichannel soundtrack, your home theater receiver is sending a unique channel of sound to each speaker in your surround sound system. Dialogue and on-screen action are sent to the center channel, which is placed directly above or below the TV. The front left and right speakers team with the center to provide a front soundstage — events on-screen, like a Harley zooming past, are emphasized as the motorcycle's guttural roar moves from the left speaker, to the center speaker, and to the right speaker, before dying out. It's a very effective way to enhance action.


Your surround speakers handle off-screen effects and ambient noises. Although this is a more subtle role, the right mix of sound in the surround speakers can turn good movie sound into great movie sound. A perfect example is in the movie Signs, when Mel Gibson's character and his family are hiding in their old farmhouse, listening to the light, rapid footsteps of alien creatures running along the porch outside. The creatures are searching all over for a way into the house, and the understated taps and creaks of their hunt encircle the watcher and add to the eeriness of the scene.

And finally, in a typical multichannel surround sound system, low bass is passed along to a powered subwoofer. This is the ".1" in "5.1-" or "6.1-channel," and boy does that low-frequency channel have an impact! Thunderstorms, explosions, the roar of a dinosaur — they all come to life with good home theater bass. (Quick note: Because a powered sub has its own built-in amplifier, this is the one signal in a multichannel system that doesn't need to be powered by the receiver. That's why 6.1-channel receivers have power ratings like "100 x 6.")

Got it? Great. Then let's take a look at the basics of 6.1.