Good time to go digital

Sound recording technologies change very quickly. This is mainly due to the fact that hard disk recording and digital tape today offer us accessible alternatives to traditional analog equipment.

Even though many post-production studios use multitrack digital tape recorders (which combine high-quality sound with ease of handling), the tape is still unwieldy. While digital tape is very useful for studios that work exclusively with audio, most of those that produce audio for video prefer hard disk recording systems.

If one of these systems can record, edit and mix an entire audio program in the same work environment , we call it the Digital Audio Workstation EAD or DAW. These types of equipment are excellent for editing, but they also have many other advantages.

Hard disk recording converts sound into computer information. Once digitized, we have almost the same flexibility as that of a word processor: we can cut, copy and paste different fragments with ease; audio can be displayed graphically on a screen. It is even possible to revert several levels of editing, so that we can return several steps, if necessary.

Most EADs provide signal processing functions, such as equalization and dynamic processing (compression). However, digital processing does not necessarily occur in real time, since the equipment only handles a certain number of tasks simultaneously. The software can resort to procedures such as background processing: for example, it processes signals only when a high-priority function is not being developed.

Of course, all EADs generate a lot of information. Typically, each minute of material uses about five megabytes per channel (44.1 kHz digital audio at 16 bits). Thus, for example, a four-minute program that uses 16 tracks will require 320 Mb of memory.

Nowadays this is not a problem because of the size of today's hard drives. The problem occurs when the user has to make backup copies of their material. Most use some form of portable storage (such as rugged magneto-optical cartridge discs) or digital tape (such as Exabyte). Of these two formats, tape is slower but cheaper.

While we can buy EADs of all prices and configurations, it is possible to classify them into three main families: dedicated equipment, personal computer controlled equipment, and systems based on the expansion of a personal computer through port cards and peripherals.

Before, all EADs (like the legendary Fairlight) were dedicated systems that one simply connected and used. Thus, although dedicated high-profile digital systems are still manufactured, equipment that looks more like a traditional recorder than a computer is also achieved. This is the case of the Otari Radar systems, the Roland VS-880 and the DR8 and DR16 Akai of Akai, among others.

Some of these devices bring the option to expand tracks and memory, or to add a video screen that allows editing by means of waveforms. The main advantage of these systems is their ease of use; its main disadvantage, the lack of flexibility compared to computer-based equipment. Therefore, although they are suitable for recording audio, they are not very common in post-production.

A good example of this type of EAD is the Soundscape SSDR1 and the TimeLine Vista DAW-80 system, which use the computer to control a dedicated audio processor. Since the specific hardware does the job of signal processing, it is not necessary for the computer to be particularly fast or powerful, since its basic function is to run a graphical interface that allows the system to be managed.

The performance of personal computer-based computers depends more on the performance of the PC than on the audio equipment itself. Faster computers allow the use of more tracks, more agile editing and more real-time functions (such as the equalization of signals while listening to a track).

As computers improve, EADs become faster and cheaper. Digidesign's Pro Tools systems dominate the audio field for video (figure1 shows the editing window of version 4.0, and Figure 2 shows that of the mixer). One of the important features of Pro Tools is the TDM bus option, a modular architecture that allows additional functions to be integrated through plug-ins from other companies – from voice processors (Figure 3) to guitar amplifier simulators.

However, there are many other EADs such as those manufactured by Sonic Solutions, Spectral, Micro Technology Unlimited, Ensoniq, etc. Like Pro Tools, these solutions typically include an audio interface that allows sound signals to be digitized on the computer; a card that speeds up audio processing and provides DSP functions, and the software to integrate the system.

It is up to the user to get hard drives, monitors and some accessories (such as computer controls with faders, switches and buttons in the traditional way, without relying only on the keyboard and mouse). There are even low-cost systems (Creamware, Digital Audio Labs, Korg, Metalithic Systems, among others) that include the sound interface as part of the computer card. There are also "a la carte" systems in which one can use the card of one manufacturer and the programs of another.

So, while you're looking for the right EAD for your needs, remember that specifications aren't everything: pay close attention to your intuition; you should feel comfortable with the equipment you are going to acquire, among other reasons because you will have to work intensely with it.

On the other hand, EADs usually have a large number of windows open simultaneously, which allow you to view the audio, the list of events that occur at certain SMPTE times, signal processing parameters and many other things. The larger the monitor, the easier it will be for you to see the information on the screen.

If anything, EADs have greatly simplified the world of post-production and made it easier than ever to add audio to video in an accurate, fast and relatively cheap way. If you haven't digitized yet, you certainly will soon. Whether you're making audio for video or upgrading your equipment, now is a good time to go digital. TV&V