Today’s Show:
Surround Sound – The New Formats
We came across an article at Home Theater Magazine about the various 7.1 speaker configurations available today. It got us thinking. Do we take the standard 7.1 configuration: 3 in the front, 2 on the sides, 2 in the back, for granted? If we could put the speakers anywhere we wanted to, where would they go?
5.1 to 7.1
Traditional 5.1 surround sound systems place three speakers in front of the listening position, a left speaker, a center speaker and a right speaker. The additional 2 speakers were meant to add sound around you, and were traditionally placed immediately to your left and right, maybe slightly behind the listening position. The 7.1 speaker configuration added two more rear surrounds, they are meant to be behind you to the left and right.
Hearing is Important
So with 7.1 setups, you have more speakers off to the sides and behind you than you do in front of you. The human ear is very accurate at pinpointing sounds when they’re in front of you, that accuracy diminishes quickly as the sound wraps around behind you. You may be off by a couple degrees in front, but as many as 20 degrees behind.
Couple that with the fact that there is almost no 7.1 content available today. DVDs max out at 5.1, so they’re off the table. According to the website blu-raystats.com , roughly 7% of the available discs include a 7.1 soundtrack, only 162 of almost 2300. So if you can’t really hear it, and there really isn’t anything to hear anyways, how important are those extra 2 channels? That’s exactly what the folks at Dolby and Audyssey would like you to think about.
New Options
Dolby Pro Logic IIz
We’ve mentioned Dolby’s new Pro Logic IIz format before. The main takeaway is that it adds height channels to your home theater. To do that they move 2 of your 7.1 speakers from the back to the front, and raise them up above the listening position, pointed down. Obviously it’s easier to run a few more wires in the front than it is to run them all the way to the rear of the room, so that’s one plus right away.
Since there aren’t any movies mixed in IIz, the Pro Logic technology fills those two height speakers with ambient sounds from other channels in the track. Pro Logic can create the IIz effect from a 2 or 5.1 channel source. Eventually it will support a 9.1 configuration, the standard 7.1 plus the two height speakers. The results of the Pro Logic processing are mixed. A reviewer from Home Entertainment Magazine loved the effect, whereas the reviewers at CNET were underwhelmed.
Audyssey DSX
Another entrant in the modified 7.1 arena is Audyssey’s DSX technology. In addition to the height channels, DSX adds additional width channels to the front of t...