We’ve been talking about home theater sound formats for the last several weeks on the Home Theater Installation Orange County blog. We’re getting close to the end of this series now. So far we’ve covered all the major 5.1-channel and 7.1-channel formats, and we’ve shared a bit of a tutorial on what those designations are all about.

If you’re just joining us, we highly recommend you read the previous posts in the series before continuing.

9.1: The Next Frontier

For many consumers, a 5.1- or 7.1-channel system will meet their expectations and create a perfectly enjoyable home theater experience. But some of you want even more. The next evolution in home theater sound is 9.1-channel audio.

As you might expect, 9.1-channel configurations add two additional channels, which correspond to two additional speakers. One great thing about 9.1-channel formats and equipment is that both formats can automatically upmix any source to utilize all the speakers in your system.

Let’s look at the two 9.1-channel formats on the market today.

Dolby Pro logic IIz

Dolby’s 9.1-channel format can upmix any source, adding front height effects to what would otherwise be a 7.1-channel sound. These front height speakers are the two new channels, and they are placed high on the wall above your front left and right speakers. They add further depth and dimension to your sound.

Auro-3D

Auro-3D takes a slightly different approach. Remember those additional rear speakers we gained when we bumped up to 7.1? Auro-3D ditches those in favor of a “full 3D” soundscape. With Auro-3D, you add height speakers (up high on the wall) above your front left and right as well as your surround left and right. In a way, you’re sacrificing a bit of surround immersion, but the trade-off is a much greater sense of 3D sound immersion.