Analogue To Digital: Changing From 8-track Tape To Hard Disk Recording

Stephen Bennett chucks his trusty 8‑track tape setup in favour of one of the new hard disk multitrack systems — but not before doing some thorough research. Here he reveals the factors that influenced his decision...

Sometimes the high prices of desirable recording equipment can be a blessing. If it costs several hundred thousand pounds you just know there is no way to afford it, so you can comfort yourself with reviews and with popping down to the nearest music store for a quick ogle. When multitrack hard disk recording equipment cost the same as a semi in Fulham, it was easy for me to sigh and press my nose against the shop window. Now, however, systems are coming down to the price of a second‑hand car. So I start to think — well, if I do a bit of fasting...

But why change from my trusty Fostex M80 8‑track and Seck desks? After all, I've recorded three albums on this equipment and the last one came out on CD. Nine out of 10 of my friends can't tell the difference between this home‑recorded album and one recorded in a studio costing several hundred pounds a day. This is either a testament to the quality of budget recording equipment or to the fact that I have particularly deaf friends.

In fact, there are several reasons why I decided to change my recording system. Firstly, I hoped it would press me into a new way of recording, as I felt I had reached the limits of my present system. I decided I needed a change — if you become too familiar with something you tend to fall into the same way of doing things. I wanted to impress my friends, and I had been looking for an excuse to get a Macintosh ever since I first started reading Bloom County. And finally, I wanted a DAT editing and compilation system

Sound quality was not one of my reasons. As I stated earlier, my analogue system was easily capable of CD‑quality recording, and my noisy effects units make a nonsense of any 'digital silence'. I could have gone for one of the 8‑track digital tape machines or, indeed, an analogue 16‑track, though that that would have meant a much bigger, and more expensive, mixing desk. However, neither of these options would have given me the advantages of hard disk recording. But can a hard‑disk based system really replace a tried and trusted 8‑track analogue tape machine in a real studio? In this article I'll pass on my experiences on making the transition, as I'm sure a lot of you are thinking of doing this soon.

For the purposes of this article, I intend to concentrate on systems that could be a direct replacement for an analogue 8‑track, which excludes the 2‑in/2‑out, 4‑track systems such as Audiomedia, SAW and Card D. While these units are ideal for adding a few tracks to a MIDI system, or for compiling DAT masters, the lack of separate outputs or sends and returns limits them severely in a multitrack recording environment. I'm also assuming that the serious project studio owner will have a computer, a mixing desk or two, and some outboard, such as effects units.

The Options

At the sub‑ £5000 end of the HD recording market, there are two choices: stand‑alone systems, and computer‑based systems. Stand‑alone systems generally try to mimic the way tape recorders work, but with the added benefit of manipulating the audio after it has been recorded. The computer‑based systems are usually internal cards or peripherals hung off a computer. Both types of system have their advantages and disadvantages.

Stand‑alone systems are good in that they are reliable, with close software/hardware integration within one box; they can be used with or without a computer system; they're easy to understand since they mimic the multitrack tape machine as closely as possible; some can use inexpensive IDE drives rather than more expensive SCSI ones; and they can be more cost‑effective than other systems. On the downside, third‑party software support may be limited or non‑existent, and these systems may be relatively 'closed', with limited upgrades to hardware and software.

The advantages of computer‑based systems include the fact that they allow the visual editing of audio data; they can be more open, so you can mix and match software from various companies; they can integrate well with other music peripherals and MIDI software such as editors and sequencers; they use standard components, making hardware improvements, such as slotting in a more powerful computer, simple; and you get a powerful computer for other tasks. Less positive aspects of stand‑alone systems are that they can be more prone to computer crashes and unreliability caused by software incompatibilities; and they can be slower than stand‑alone hardware systems.

Hard Disk Advantages

Whatever type of system is chosen, hard disk recorders have some advantages over conventional tape‑based systems — as well as some disadvantages. They allow you to achieve more complete integration with your sequencer — if you use an audio version of a popular sequencer, such as Opcode's Studio Vision Pro, you can record MIDI data along with audio and almost treat your audio material as you do MIDI data. This can also be achieved by synchronising audio‑only software, such as OSC's Deck II, with a conventional MIDI sequencer. This is not as convenient as using an audio sequencer, though, as you will have to swap between the two programs to record MIDI and audio. The software supplied with hard‑disk recording hardware is often more powerful than that integrated into audio sequencers. For example, while the software supplied with the Digidesign Session 8 hardware allows punch‑in on the fly, four EQs per track and the bouncing down of audio tracks, the present versions of Cubase Audio and E‑Magic's Logic Audio do not. But these are software limitations — forthcoming versions should allow all these things and more.

• VIRTUAL TRACKS
  With 8‑track tape you get eight tracks — period. If you don't bounce tracks (which will add to noise and distortion) the only way of adding extra audio recordings on each track is to punch in and out. Hard disk recorders usually have a fixed number of tracks that can be output at the same time, but the number of audio tracks that can be recorded is usually much greater. For example, in an 8‑track HD system using an audio sequencer like Cubase Audio, up to 64 tracks of audio can be recorded, though only eight can play back at any one time. (Figure 1). This means, for example, that you could record six tracks of backing vocals, bounce them down to stereo and then mute the original tracks. You don't need to delete the pre‑mixed tracks — they just don't play back. If later you don't like the vocal mix, you can simply remix. Any permutation is possible, the only rule being that no more than eight tracks can be output simultaneously.

Different systems have different methods for specifying which tracks are output if there are overlaps. Punching in and out can be done to millisecond accuracy and, usually, each take is kept so you can recall it at any time (Figure 2). You can also compile the 'perfect' take from all the recordings. Software‑based EQ can usually be applied to each audio track and to each separate portion of that track.

• AUDIO EDITING AND CUT 'N' PASTE
  It's well known that using a hard disk recording system makes it easy to copy bits of music around, reverse them, fade them and generally muck about with them to your heart's content. After all, it's only data. But you can also load in other audio from CD or DAT, stretch parts to fit your MIDI data, and change the pitch of an audio file. Generally speaking, anything you're used to doing with MIDI data is possible with audio — and in real time, thanks to the DSP (Digital Signal Processing) in hard disk recording systems.
• COMPILING PROJECTS
  A multitrack HD recording system is invaluable for compiling your finished project. Because transfer between the HD recorder and a DAT recorder is digital, it brings many benefits. You could, for example, mix tracks in sections of a couple of minutes at a time onto DAT. This is really useful for complex mixes, as it allows you to concentrate on one small section of the track at a time. The whole lot can then be re‑loaded back onto the hard disk and 'glued' together to produce the finished piece. People often used to do complex mixes like this onto stereo reel‑to‑reel and then splice them together. Think of what Mike Oldfield would have given for hard disk facilities when he was recording Tubular Bells!

Even adding links between tracks is easy with a HD system. Load the first song onto tracks 1 and 2, the link onto 3 and 4 and the second song onto tracks 1 and 2 again. Then use the software to fade into and out of the link — instant Pink Floyd. When you've finished compiling, you can digitally transfer it back to DAT (Figure 3).

Problems

• RELIABILITY
  You don't get something for nothing, and hard disk recording is no exception. In my five years of running a Fostex M80 8‑track, I had not one problem with the machine — no drop‑outs, no crashes. HD systems, whether stand‑alone or not, are based on computers. Think about that for a moment — computers, the same computers that deduct £14 from your bank account without asking, that suddenly convert all the characters in a letter you are writing into 'z's, for no apparent reason... Luckily, some computers are more reliable than others, but HD systems still seem to crash fairly regularly. Usually you don't lose recorded audio when this happens but it can still make you start to sweat.
• BACKING UP
  When your hard disk is full, or when you want to back up your precious recordings, you'll need some way of offloading your data. Removable disks or dedicated tape backup devices, such as Exobyte or DAT (not audio DAT) are the best. These provide good data integrity, but are either expensive to buy or expensive to feed. But most HD systems also allow you to back up to your audio DAT recorder. This seems like a good deal — after all, many studio musicians also already own a DAT recorder. Some systems also allow backup of all non‑audio data to DAT. But there are some problems you should be aware of:

1. Each minute of audio recorded at 44.1kHz takes up about 5Mb of hard disk space. Eight tracks need 40Mb per minute. So a five‑minute song with, say, several takes and muted tracks could easily fill up your 1Gb drive. As the backup to audio DAT is in stereo and real time, it could take around 100 minutes! And you can't skimp on backing up — hard disks crash when you least expect it. Neither does audio DAT have the error‑correction and logging that the dedicated backup devices do. You may not know you have lost data until you reload the session. Remember that you won't just be backing up data for safety — you will be wiping the hard drive, recording a new session, reloading earlier work, and so on.

2. Will you be able to use your existing DAT recorder for DAT backup? You may need an SCMS (Serial Copy Management System — the code that inhibits digital copying on many domestic DAT machines) stripper, as the backup is done digitally. Without it, you may not be able to do a second digital copy of your data. Most HD systems use SP/DIF coaxial cables for DAT backup. If your DAT recorder has only a SP/DIF coaxial output (like the popular Sony DTC690), or just optical in and out, you'll need an adapter. There are some units that solve both these problems. Turnkey, for example, make a combined SCMS stripper/optical‑to‑SP/DIF converter for about £120. Just make sure you sit down before they tell you the price of the optical cables. It goes without saying that you should only use the best quality DAT tapes and follow the DAT manfacturer's instructions. If possible, back‑up the backup!

Other Potential Problems

The other problems HD recorders bring are generally ergonomic ones. A mouse and a computer keyboard are no replacement for faders and the start/stop buttons on an 8‑track tape machine. MIDI fader boxes, such as the JL Cooper CS1, go some way to alleviating this. The cramped conditions on the computer screen created by using several pieces of software, each with several windows open, can be overcome by using a larger monitor, though these can be very expensive. There are also some questions to be asked about the speed of the computer. Screen redraws and disk saving can become so sluggish as to really try your patience. That said, I have had few problems in this repect with my Mac IIfx, a 3‑year old '030 machine.

Another problem I came across when starting to use the HD system was noise from the computer. Many of you, like me, will have one room that is both the control room and recording room. The fans inside a computer and external hard‑drive can make a hell of a noise. The answer is to put the computer in a box or cupboard or in another room! I use a large wooden box. A couple of 12v fans move the air around the box. Don't completely seal it, though — your computer needs air‑flow if it is not to overheat. Remember, too, that while you can freely extend monitor and keyboard cables, SCSI disk drive cables cannot be more than a foot or two in length.

What You Need

One of the hardest tasks I faced when I decided to go HD was determining what equipment I would actually need. I wanted to set up a fully‑functioning 8‑track system that would at least equal the capabilities of my tape‑based system, which consisted of: Fostex M80 8‑track; Seck 18:8:2 mixing desk and 18:2 sub‑mixer; Casio DA2 DAT; various effects units and synthesizers; Atari ST computer running Cubase and MIDEX+ SMPTE synchroniser.

There are several possibilities for integrating a hard disk multitrack into this type of system:
• Replace the 8‑track with a stand‑alone HD system.
• Replace the computer and 8‑track with a computer‑based HD system and, perhaps, an audio sequencer.
• Replace the computer, 8‑track and multitrack mixer with a 'studio'‑type HD system, like Digidesign's Session 8.

You'll also need the following:

• A large hard disk: In general, this should be an additional drive and not the drive you store your software on. Its capacity should be about one and a half times bigger than you think you'll need, and then usually plus some! You must take the advice of the manufacturer of your chosen hard disk system on the type of drive to buy, as not all drives are suitable for HD recording — most hard drives pause occasionally to perform a thermal calibration, and this disrupts the data flow to and from the disk. Lists of suitable drives are available from the hard disk recording system manufacturers, and on the Internet.
• Disk defragmenting software: as files are recorded and deleted, the bits of information making up the file become spread across the disk in discontinuous fragments. When this happens, it takes longer for the HD system to find the data on the disk, leading to 'disk too slow' messages. Defragmenting the disk can be done without deleting data.

The Computer

Regardless of which computer you decide to buy, the following applies: get the most powerful computer you can and as much memory as you can afford. There are some guidelines to follow:

Atari Falcon: get the maximum memory of 14Mb.

PC and Mac: 16Mb is the minimum memory you need to do HD recording. If you want to use a sequencer or editor, get more.

You should also be aware that most computers have 1‑, 2‑, 4‑ or 8‑SIMM memory slots. This means that if you have, say, 16Mb of memory, as 2Mb SIMMS in an 8‑slot system, you may have to sell all these and replace them with 4Mb SIMMS to upgrade. Different computers have different configurations and it is essential to check these when you buy the computer. It may be cheaper in the long run to get more memory straight away.

Your choice of computer can depend heavily on the use you want to make of your system aside from music. As I write, there are three computers suitable for 8‑track HD recording systems:

• Atari/C‑Lab Falcon
  Though Atari have exited from the Falcon scene to concentrate on the games market, C‑Lab have taken over production of the Falcon and are optimising it for audio use. The Falcon still represents the most inexpensive way into HD recording, but there is less audio software available for this machine than the PC or Mac.
• IBM PC & Compatibles
  Several computer‑based and stand‑alone systems are available for the PC. These usually require you to synchronise the recording software to existing MIDI sequencers, as few 'audio' sequencers support the PC‑based systems directly at the moment. You need a pretty powerful PC just to run the Windows operating software at a reasonable speed, so for HD recording the fastest is definitely best. The bottleneck in a Windows‑based PC system is usually the video hardware, though there are video/Windows hardware accelerators available. They can, however, cause problems with peripherals like HD recorders. There are some improvements coming soon that may make PCs more suitable for HD recording, including the new, Mac‑like, Windows 95 operating system, Opcode's OMS for Windows, and better MIDI integration into the operating system. These should all come about in 1995, so watch this space.
• Apple Macintosh
  At first glance, the Mac appears to be the ideal computer for HD recording. It is simple to use, reliable, and has the longest history of HD recording. Software like Digidesign's Digital Audio Engine (DAE) and Opcode's Open MIDI System (OMS) make it easier for various manufacturers to write integrated HD and MIDI programs. Sound files created by different software is generally in the Sound Designer II format, allowing easy data transfer between different programs. This, combined with the widest range of add‑on software and hardware, such as DSP‑based reverbs, CD mastering, NuBus‑based Lexicon reverbs and Emu Proteus modules, makes the Mac a powerful recording tool.

There is something nasty in the woodshed, though. The first difficulty comes when trying to buy a new Macintosh for HD recording! There has been much discussion on the Internet about the incompatibilities of the MacOS emulation and NuBus slots on the new PowerMacs. The '040 Macs available don't have NuBus slots, which are essential for HD recording. The AV series of Macs that do have NuBus slots are also reporting problems with HD systems. AV Macs, using their on‑board DSPs, do not have multiple outputs or effects sends. Luckily, the secondhand Mac market is healthy at the moment, as people move to PowerMacs. Many a bargain is to be found. Even some '030 Macs are easily as powerful as the latest 486‑based PCs. (For a rundown of the capabilities of the older Macs see SOS January '95, page 78.)

Macs less powerful than the IIci are not recommended by manufacturers for HD recording. The ideal Mac for HD recording, in my opinion, was the Quadra/Centris 650, which had three NuBus slots and was very fast. Some music suppliers still have a few of these, but be prepared to pay an arm and a leg for them. Apart from the caveats above, any Mac more powerful than the IIci and with more than one NuBus slot can be used for HD recording. For the record, I finally got a second‑hand '030 Mac IIfx. It came from a dealer in used Macs and has 20Mb RAM and a 170Mb Hard drive. I got a six‑month guarantee, it cost £700, and it works just fine!

In general, when you decide on a software/computer/hard‑disk combination, you should contact the HD and software manufacturers to make sure the components you're buying will work together. If you decide to go the 8‑track, output‑only route you'll just need to sell your old 8‑track. If you decide to go for a system that provides effect sends, returns, inserts and automated mixdown all in the one box, you could sell your desk too! Or, alternatively, you could use it as a sub‑mixer for your MIDI keyboards.

Buying The Gear & Getting Advice

I found it very difficult to get accurate information and advice when I decided to buy a HD recording system. Retailers, in general, only knew the overall capabilities of the systems they were supplying. The companies who specialise in HD recording tended to be the most informed. After a few phone calls and demos, I found I was a bit bewildered. What did I really need to buy? How much was it going to cost? None of my colleagues had much experience with HD recording, so I turned to the Internet for advice (see box on help on the Internet elsewhere in this article).

I posted several queries in newsgroups and mailing lists and was bombarded with helpful advice. This came from both users of systems in real studio situations and from on‑line manufacturers. A lot of replies came from the USA where, inevitably, HD recorders are much more common. This help, along with software upgrades and bug fixes available from FTP sites, became invaluable. My advice is — add a modem and on‑line costs to your purchase.

A Typical Session

Using the HD system on a day‑to‑day basis has required a little more concentration on my part than with my old tape‑based system. Routing inputs to tape tracks is done in software, and there are no flashing lights and meters to guide me if the relevant windows are hidden. Using an audio sequencer, I now tend to record several takes and either choose the best, or do a cut and paste. I don't need to worry about levels so much either. As long as I'm well under 0dB, I can normalise the data later if I need too. This doesn't seem to add much noise if the source is quiet.

Mixing is suprisingly easy. It's so simple to loop a small part of the song I'm working on, set the level, EQ and effects on each track in turn and then move on to the next bit. Crashes are a regular occurrence, but as data is read directly to disk, I have usually been able to recover the recordings. I had to put a mains on/off switch on the flying power lead of my Macintosh for rebooting — remember, it's in a box! All in all, I think I can live with the HD system, especially with regard to the benefits it brings. If I was working to the clock, or had paying customers, I would be more wary. Many people use a multitrack tape machine for recording, transferring the results to a HD system for editing. This is a much safer bet if you have customers looking over your shoulder as you reboot the computer for the tenth time that session.

The Future

With the advent of more powerful and less expensive computers, it cannot be long before a complete recording environment becomes available all in one box. This system could contain a multitrack hard disk recording system, DSPs, software‑based effects units and perhaps software‑based 'synthesizers'. The integration with video editing will improve too The major problems at the moment are software reliability and data storage, though these are being overcome by mainstream computer innovation. Because the major manufacturers seem to be engaged in an evolutionary development of their systems, there is no reason to put off buying a system 'till tomorrow'. The TDM system available on the Mac from Digidesign is a particularly exciting step forward. It promises the prospect of buying a modular HD system, starting off with an inexpensive basic unit and adding more tracks and features as the budget allows. The interface between MIDI, software plug‑ins and audio recording is becoming more integrated and open between manufacturers. The future of HD recording should be a rosy one indeed.

Oh, and by the way — a hard‑disk recorder can replace an 8‑track analogue system. It's up and running in my studio!