Surrounded by Sound

Dec 1, 1999 12:00 PM, By Vance Galloway and Scott Wilkinson

           
 

WHY 5.1?
Most engineers, producers, composers, and musicians have been working in stereo for their entire careers, but they are becoming 5.1 converts in droves. Why? Because of the effect it has on the listener. The sense of realism, the apparent acoustic space, the impression of "being there" can be overwhelming to ears accustomed to stereo. Two well-known mixing engineers actually claim they've been driven to tears of joy while mixing in 5.1 because of the format's impact.

Others who are a little more restrained simply point out that humans are able to localize sounds that originate from any direction, and 5.1 is much more capable of stimulating this ability than stereo. Musicians and composers are particularly attracted to 5.1 because of the artistic possibilities it offers.

However, there is some disagreement about how 5.1 should be used. Most of these arguments revolve around aesthetic decisions that the producer, engineer, or composer must make. Some want to use the extra speakers to experiment with radical spatial placement of sounds. Others abhor this approach, and prefer to use 5.1 to heighten the listener's sense of being in an acoustic space. Debates of a more technical nature, such as which elements of the mix should be routed to the LFE channel, also abound.

It should be noted that 5.1 has its own technical limitations. This is not the ultimate be-all and end-all of channel formats. For example, experts agree that the surround-sound effect can be greatly enhanced by adding even more channels and speakers. Dolby is experimenting with a 6.1 format for commercial cinemas called Dolby Digital EX, in which a center speaker is placed in the rear. In addition, several surround processors synthesize 7.1 channels of sound from 5.1 material. Systems with 12 or more channels are being tested for use in theaters and other specialty locations. However, the advantages of adding more channels must be weighed against the immense difficulty of transmitting, storing, and reproducing an increased amount of audio data.

GETTING IN THE GAME
There are several pieces of gear that are unique to 5.1 mixing, but owners of modern project studios probably already have some of the items that are required to get started in 5.1.

First of all, you need to have enough speakers and amplification to reproduce five full-bandwidth channels and one low-frequency channel. Several companies, including Event, Genelec, Tannoy, Dynaudio, JBL, and Bag End, offer speaker packages specifically for 5.1 studio monitoring. Many of these packages include five matched speakers for the main channels and a subwoofer for the LFE channel. However, some engineers prefer to use smaller speakers for the surround channels, imitating the configuration common to many households.

Next, you need a way to pan sounds among 5.1 channels. Many newer mixing boards targeted toward the project-studio market are capable of mixing in 5.1. The Yamaha 02R and 03D, Mackie D8B, Tascam TMD-8000, Panasonic DA7, and the Roland VM series of digital mixers all provide this capability. It is possible to create 5.1 mixes with boards that do not include surround-panning features, but it is quite difficult, and the impressive cost/performance ratio of the new mixers makes them very attractive.

FIG. 2: Minnetonka Software’s Mx51 is a PC-based DAW with the ability to do 5.1 panning.

Several digital audio workstations now include 5.1 panning in their core software or allow the use of plug-ins that perform this function. Minnetonka Software recently introduced Mx51, a PC-based DAW with the ability to do 5.1 panning with the Digital Audio Labs V8 card or the Yamaha DSP Factory card as its audio hardware (see Fig. 2). Sonic Solutions' new Sonic Studio HDSP workstation includes surround panning as a standard feature.

Pro Tools owners can use the SmartPan Pro plug-in by Kind of Loud Technologies to perform 5.1 or even 7.1 panning on Pro Tools 24/Mix or MixPlus systems. SonicEngineering has introduced the Panhandler plug-in for DirectX hosts, Innovative Quality Software's SAW, Adobe Premiere, and Syntrillium's Cool Edit Pro. The 5.3 version of SEK'D's Samplitude 2496 includes extensive surround mixing, and Steinberg's forthcoming Nuendo audio production software will also offer surround support. Rest assured that many more 5.1-capable DAWs, plug-ins, and mixers will appear in the near future.

What sort of device should you use to record your 5.1 mix? Any machine that lets you record six full-bandwidth audio channels will do. At present, the most commonly chosen option is multitrack tape. The nearly ubiquitous DA-88 and ADAT formats are excellent choices because of their popularity and their ability to record a 5.1 and stereo version of the same mix on the same tape. Mixing to a DAW is a great choice, especially if it lets you achieve better-than-CD audio quality, such as 24/96.

Depending on the delivery format you are mixing for, you might need to encode your 5.1 mix using a data-compression method such as Dolby Digital. This requires an appropriate encoder. Hardware encoders are expensive and sometimes available only by leasing, so the best option is usually a software encoder. Sonic Foundry offers SoftEncode, a PC-based application that allows six audio files to be encoded into 5.1 Dolby Digital. Astarte has announced the imminent release of A.Pack, which performs the same feat on the Mac and PC. Sonic Solutions offers a Dolby Digital encoder for its Mac-based workstations that provides real-time encoding.

FINAL THOUGHTS
The new 5.1-channel format provides audiences with a greatly enhanced listening experience, and it provides artists and engineers with an expanded palette of creative possibilities. In addition, it produces these impressive results while remaining within the limits of the existing and emerging technologies that are (or soon will be) in the hands of the public. Enthusiastic acceptance by audiences and leading audio professionals indicates that 5.1's future is fairly well assured.

Of course, the 5.1 format does have its limitations, and debates about its "proper" use will simmer for quite some time. It is important to remember that this is typical for a new format. Nevertheless, 5.1 is an amazing advance beyond stereo, and the equipment to produce it and play it back is commonly available and relatively affordable. All of these ingredients add up to one conclusion: It is high time to take a closer look at 5.1.