Audio AND video: A true partnership

Matching high-quality HD video with audio
Publish date:
Social count:

StarCity Recording Company’s “A” room, its surround mixing room, is outfitted with a Solid State Logic 9000 K console, Quested 412 monitors soffitted into the walls (five of them in surround fashion) and a Stewart Microperf screen.

The more things change, the more they stay the same. Take the motion picture industry, for example. Years ago, someone working as a projectionist in a high-quality cinema might be familiar with the following scene: a bright, steady lamp house; great optics; and a large concave screen. The visual product was gorgeous.

Audio integral to broadcast quality

But the sound system … yikes! Amps with wax capacitors melting from the heat of the glowing tubes of the amp below it, speakers that sounded like cardboard … you get the picture. It was the perfect recipe for developing an imbalanced sense of quality — exceptional visuals supported by a disproportionately lower standard of audio. That's a bit of an overstatement perhaps, but it's worth saying to make the point.

The HD viewing experience available from the networks and satellite providers on today's great display technology is jaw-dropping. It is obvious that a tremendous amount of care has gone into this consumer-level end product, as well as every step along the way: acquisition, post, output and broadcast. But has the audio component of these broadcasts kept pace? Does it matter?

Helen Keller was once asked if she could have either her sight or her hearing restored, which would she choose? Without skipping a beat, she replied that she would want to hear. Worth pondering, isn't it? The audio portion of your broadcast is arguably 50 percent of the experience. In an effort to put forth an audio presentation as quality-driven as its aforementioned visual counterpart, audio budgets on any HD (or SD, for that matter) project should be comprehensive enough to include an adequate completion time figure, the right equipment, accurate acoustic environments and, most importantly, qualified engineering.

The first step toward problems within the audio realm starts at the budgetary and strategic planning stages of production and can carry through to completion. These problems are compounded by the less than perfect handling of project flow, asset complexity and client interferences.

Proper equipment aids results

Department heads take note: When it comes to audio, do not underestimate the importance of proper project planning and project management. In the line of fire of a complex production, nothing can derail your timetable and budget quicker than the chaos of mismanagement. Many ill-conceived, poorly managed projects are saved only through the heroic efforts of highly skilled audio professionals functioning much like military Special Forces — against the clock, no help from the chain of command and accomplishing mission objectives with only spit, duct tape and chewing gum.

Now, not all productions are as complex as, say, a motion picture, but the same tight planning and managing necessary for meeting budget/deadline/quality benchmarks on a motion picture benefit even the smallest project. Installing regulating systems at a time when things are simple provide stable management structure as your production house grows.

When handling acquisition, whether in the field, stage or studio, audio professionals hand-select specific microphones to successfully capture a particular instrument, voice or sound. A deep mic closet is hugely beneficial. Capturing audio in a live setting, as for an HD concert broadcast, requires an appropriate isolation of the instruments through stage set-up, mic selection and mic placement. Signal chains must be pristine; no extraneous noise should be induced. The listening environments must be quiet enough to hear the slightest hums, buzzes and noise floors.

Figure 1. Shown here is the Optimized Cardioid Triangle surround technique. Click here to see an enlarged diagram.

The February 2005 issue of Broadcast Engineering featured an article titled “Monitoring Surround Sound Audio for Broadcast,” which focused primarily on phase issues that arise when down-mixing is performed on a 5.1 mix (as is often the case in the consumer environment). This is an important consideration both electronically (as in the interconnect scheme) and with the placement of the microphones. Phasing errors, at times barely audible when monitoring in surround, can become quite apparent when folded down. It takes trained critical listening skills to hear subtle phase issues.

Additionally, industry standards exist with regard to microphone technique in surround acquisition. One such example is the Optimized Cardioid Triangle surround technique, a methodology for acquiring true phase coherent surround field audio. (See Figure 1.)

Having the right tools in place to perform down-mixing in adherence to consumer-based standards is important. For example, the Dolby 570 monitoring tool provides precise emulation of the Dolby decoded consumer environment. With this tool, all flavors of down-mixing are accounted for, as well as the effects of any compression profiles applied. This can be extremely helpful.

End product dependent on environment

When producer Jeff Glixman worked on the surround remix of the Allman Brother's “Live at the Fillmore East” for Sony SACD release, he used the original multi-track transfers. Much care was taken to delay times on the open mics — especially the audience mics — so that under down-mix duress, the best phasing characteristics were achieved. Care was also taken when using mono-to-surround enhancement tools for the same reasons.

Having the right tools is essential to creating a high-quality audio experience. StarCity’s “B” room, its primary lock to picture editing room, employs a Dolby 564 reference decoder, Dolby 570 monitor, Dolby 569 digital audio encoder, Brainstorm Electronics timecode distripalyzer and Eventide Orville digital effects processor.

Working in a facility dedicated to surround is a huge advantage. The structure, room design and speaker combination can provide a trustworthy acoustic environment. Problems present during track and mix are revealed. When you have a competent engineering staff paired with the hardware and software you need in order to work without restriction, you are in an optimal situation. In this environment, audio engineers are capable of producing the finest in audio quality. They are able to “paint” with this subtle shade or that stark color. They can experiment, invent and define. They can correct. There will be no surprises when the mix leaves their hands; the frequency spectrum balance and mix proportions translate well to any given consumer or professional environment. And, most importantly, they sound fun to listen to because the mixes achieve the intended sonic quality goals.

When you see incredible looking content from your cable or satellite provider, don't you want incredible sound as well? The best that HD video and HD surround sound has to offer, combined, results in an unparalleled experience. Audio matters as much as video. Period. Do not settle for anything less than the same super highly-detailed level of quality in the audio component of your productions as you insist upon for your video.

Carl Cadden-James is vice president of production and engineering for StarCity Recording Company.