Getting Great Sound: Part III

Somebody came up to me after my final seminar at the TAVES show last weekend and said that he had just heard a presentation in another part of the hotel about the uselessness of multichannel audio. He told me that the other presenter claimed that 2.0 channel stereo could deliver a completely immersive listening experience. You can get all of the depth and dimension you’ll ever want from just two speakers. Baloney!

After listening to me rave about the benefits of investing in and installing a 5.1 surround music listening space, the guy was obviously confused. Who’s right and who’s wrong. Obviously, both of us can’t be right. Either you need to have additional speakers in your listening space or you don’t. Here’s my case for surround music listening.

The usual argument goes that a well-recorded stereo program will present a completely convincing, spacious soundfield that is full of depth and ambiance. Alan Blumlein had it right when he invented stereo recording and playback back in the early 1930s. His model of using two bi-directional microphones does, in fact, capture a very good job of capturing a live musical event. His method of recording is still referenced by many as the “only true stereo” method of recording out there. There’s even a website and logo that promotes the idea of “true stereo”. Apparently, all of the other techniques for recording with spatial information are not “true”. And this doesn’t even begin to address the merits of surround sound recording and playback.

Figure 1 – Blumlein stereo microphone setup

I don’t think that the hard-core stereo buffs have actually heard great multichannel recordings. The difference between the best stereo recording and even a moderate surround recording are dramatic. Multichannel provides a much more compelling sense of space and dimension than stereo. And if you enjoy going beyond the acoustic realities of a performance hall, multichannel audio can be an active part of the creative process. It’s part of the art of mixing. That’s why I include two 5.1 surround mixes on every disc that I’ve produced. You can sit in the midst of the band or place yourself in the best seat in the house. Of course, I provide a straight stereo mix as well for those that haven’t yet experimented with surround music.

Having more speakers just makes more sense than a dedicated stereo pair…not matter how good they are. But it comes with the added requirement of where to put the left and right surround speakers (this is why sound bars are so popular…although they don’t really do the job as well as they should).

Even the center front speaker is a problem. In a home theater room the video monitor is smack in the front where the speaker needs to go. So speaker makers make a version of their left and right models except it’s turned on it side. These units usually use the same drivers but not always. My B&W 801 III’s have a 12″ woofer. There is no sideways version of this speaker. The center speaker is always a compromise in some way and that’s why I don’t put much information it the center in my mixes. I pan to the left and right and count on a phantom center image to project the singer or soloist.

I get asked whether the speakers should be “toed in” or left facing straight forward? The plan for any speaker setup should direct the speaker drivers towards the ideal listening position AND they should be equidistant to the listener to maintain phase coherence. This means there is an imaginary circle in your listening space with you at the center. All speakers should ideally be on the perimeter of that circle and pointed directly to the center point.

I know this is sometimes hard to accomplish in your living room or home theater…but it is the ideal. You’ll get the best sound if you have 5 identical speakers arranged in a circle outputting the sound directly towards you. The left and right front speakers form an equilateral triangle with the listener’s central position. The center front speaker is at the 0 degree position along the circle position and the left and right surround speakers are located between 110-120 degrees from the center line on either side. That’s how it is in my studio and that’s how you should position your setup…if possible.