Do your backing tapes sound as if they were recorded in the shower? Does your tape machine have a tendency to eat your most precious tape at a crucial moment? Paul White examines some hi-fi solutions to these embarrassing problems.

A very large number of performers, from top festival acts to working men's clubs solo performers depend on the use of backing tapes or other pre-recorded backing material, ranging from a few additional musical parts to complete 'music minus one' arrangements providing the solo singer/player with a full backing band. Many people still use cassette tapes because they're cheap, easy to copy, and playback machines are cheap. Furthermore, commercially available backing tapes are often only obtainable on cassette. As the public's awareness of sound quality continues to increase, however, side effects such as hiss, wow and flutter, tonal dullness, and pitch errors are no longer acceptable to the ordinary gig-goer.

In this article, I will attempt to survey the alternatives, giving you an idea of their strengths and weaknesses. First though, I will identify the pros and cons of the tried and tested cassette tape that has served this marketplace for so long.

CASSETTE TAPES

Cassette tapes are definitely the poor relations in today's digital world. It is still possible, however, to achieve surprisingly good sound quality, providing the equipment is of good quality, well maintained, and used with good quality tapes. As mentioned in the introduction, there are several weaknesses in the cassette format, so I'll try to address those first.

A common problem is tape hiss, and many people still misunderstand tape noise reduction systems, which makes the problem worse. All tape noise reduction systems (Dolby being by far the most popular on commercial units) work by processing the signal in some way during recording and then applying an opposite process during replay. This ostensibly re-creates the original sound but with less tape noise. I say ostensibly, because noise reduction can have side effects which are most noticeable when recordings are made on one machine but played back on another. It is imperative that the same noise reduction system be used both when recording and playing tapes back — you can't record a tape using Dolby B and then play it back using Dolby C without experiencing some tonal changes. More importantly, you can't use noise reduction to process a tape that was recorded without it — the result will be a very dull sound.

For the best performance, use a high quality type II (sometimes called chrome type), preferably one of the brands recommended in the machine's handbook, and use a machine with Dolby C, or better still, the newer Dolby S noise reduction system. It is equally important that the tapes are recorded at a proper level — the meters should always go a little way into the red on signal peaks. If you record at too low a level, the recording will be noisy, whereas working at too high a level will result in audible distortion. The idea is to record as loud as you can without distortion.

It is also vital to clean the tape machine before making a recording, and it's also a good idea to clean it prior to each gig. A cotton bud moistened in head cleaner (isopropyl alcohol) can be used to rub away any dirt from the tape heads and guides. In practice, you just keep wiping until no more brown gunge comes off on the cotton bud, then wipe the parts again with a clean, dry cotton bud. Leave the machine to dry out for a couple of minutes before inserting a tape and you're in business. The whole business takes no more than a couple of minutes.

Assuming that your tapes now sound clean and bright, there's the problem of pitch to worry about. Tapes made on one cassette deck seldom play back in pitch on a different machine, and even the same machine can drift in speed from one day to the next. Using the same machine for both recording and playback helps, both as far as speed consistency is concerned and for making sure the noise reduction system behaves as well as possible. As some speed fluctuations are still possible, it is advisable to record a tuning tone at the start of the tape so that you can tune your instrument to the tape prior to the performance.

A better solution to the speed (and hence pitch) problem is to use a cassette deck with a variable speed control, but these are few and far between. However, most decks have an internal preset to allow the speed to be calibrated, and any competent service technician should be able to replace this with a conventional pot mounted on the rear panel. If this is possible, record a tuning tone at the same time as you record your backing tapes, then when you get to the gig, use the speed control to precisely tune the tuning tone to your instrument rather than vice versa.

If you find a good service engineer, he should also be able to fit start and stop footswitch jacks to any machine with electrical button controls (this isn't possible if the machine has mechanical transport keys). Having footswitch control makes your performance look a lot slicker, and it saves you having to walk to the recorder every time you want to start or stop playback.

Another practical problem faced by most types of tape machines is that they take longer than you'd like to wind through, so unless your songs are recorded in a fixed running order, cueing up individual songs can be a nightmare. If you're in the habit of changing your running order, then putting each backing track on a separate cassette might be the simplest option.

Always keep backups of your tapes, because even the best tape player has been known to 'eat' the occasional tape. To be fair, this is usually due to the tape being loosely wound or to the machine being dirty, so always keep your machine clean (transport it in a dust-proof case), and keep your cassettes in the type of storage boxes that include small tabs in the lid to lock the reels. If the reels aren't locked, the vibration involved in driving to a gig will almost certainly leave you with several inches of loose tape inside the cassette shell — which is the cassette equivalent of holding up a sign saying 'Eat Me'.

ALTERNATIVES

Having dealt with the cassette deck in some depth, it's time to look at the alternatives, virtually all of which offer some advantage over cassette. Having said that, some also have disadvantages that may not be immediately obvious.

Digital tape formats offer the very real benefits of virtually hiss-free recording, the elimination of concerns over noise reduction systems, and rock solid speed stability. In to this category falls DAT and Philips' DCC.

DAT

The most commonly used digital tape machines are DAT machines. They have incredibly fast wind speeds, allowing you to spin through a complete album in well under a minute. Start IDs can be placed before each song so that you can cue up new songs quickly and precisely, and because DAT is a 'single-sided' tape format, you don't have the problems associated with turning the tape over. Although blank DAT tapes cost between £7 and £10, they are still very cost-effective as the maximum playing time for a DAT tape is 120 minutes.

The down side to DAT machines is that good ones are quite expensive, while cheap ones are often unreliable. You also need to get the machines serviced after every 500 hours of use or so, otherwise you can suffer from mysterious dropouts and glitches. You'll also need to find a source of backing material on DAT as copying from cassettes will lose most of DAT's sound quality benefits. DAT machines can be cleaned with special head cleaning tapes in much the same way as video recorders, but thorough cleaning is best carried out by a qualified repair technician.

The tapes are physically compact and have door mechanisms, which offer some protection against dust. Even so, they should not be stored or transported in humid, damp or dusty environments, and, like any tapes, they should never be left inside a vehicle during warm weather or left on a window ledge in direct sunlight. Tapes should always be removed from the machine after use and wound to the start or end before storing. Again, this applies to all tape formats.

DCC

Philips' DCC system is a consumer digital tape format, designed to offer a high quality, affordable alternative to the traditional analogue cassette. The subjective sound quality is very similar to that of DAT, even though a digital data compression system is used to cram more information onto the tape. DAT uses rotating heads like those in a video recorder, but DCC uses a fixed head, which may bode well for long-term reliability. The machine can be cleaned in the same way as a conventional cassette machine and will even play back (but not record) conventional cassette tapes.

Prices are incredibly low — because DCC never made a big impact as a consumer product — and a good machine can be bought for as little as £250. DCC cassettes are comparable in price to DAT tapes.

Although you can use track IDs to locate songs precisely, the fast wind speed is closer to that of conventional cassettes than it is to that of DAT. DCC machines also feature an auto-reverse transport so the tape does not need to be physically turned over.

"Always keep backups of your tapes, because even the best tape player has been know to 'eat' the occasional tape."

Recordable Compact Disc

Now that having material transferred onto CD-R (Recordable CDs that can be recorded once only) is relatively inexpensive, it is perfectly viable to have all your backing material transferred to CD. If you're not working exclusively with your own material, however, you should consider any copyright implications in doing this (this applies to any recording format). The various aspects of copyright are outside the brief of this article, but will be explored in depth in the future.

CD-Rs may be treated in much the same way as conventional CDs, although exposure to bright sunlight for extended periods can damage them. All CDs should be treated with care — they're not indestructible — and as with tapes, it's prudent to get a backup copy made in case of unforeseen damage to your working copy. CD players are cheap; many come with useful remote controllers; and access to tracks is extremely fast. In most respects, using CD-Rs is the best option, based on convenience, sound quality, and cost. They do have a weakness though — like vinyl records, they can jump if knocked or subjected to excessive vibration, and occasionally a dirty or scratched disk will jump with no provocation. And nothing makes you look sillier than trying to play or sing in time to a jumping record! Because of the floor vibrations present due to your sound system and the (hopefully) dancing feet of your audience, some sort of vibration isolation system should be considered essential if the risk of jumping is to be minimised. At the very least, you should sit your CD player on a slab of furniture foam.

MiniDisc

Like Philips DCC, Sony's MiniDisc format was intended for consumer use, and data compression is used to squeeze a quart into a pint pot (pre-metric cliché!). As the name suggests, MiniDisc uses recordable disks rather than tape. MiniDiscs can be recorded onto multiple times in much the same way as tape, unlike CD-R. Although technically the sound quality isn't quite as good as from DAT or CD, the data compression system is remarkably transparent and few people would be able to tell MiniDisc apart from CD on typical pop material.

The practical benefits of MiniDisc are the same as for CD-R, with the added bonus that you can re-record the disks if you change your repertoire. MiniDisc recorders are more costly than CD players, but a further benefit (other than the fact that CD players can't record while MiniDisc recorders can) is that MiniDisc incorporates a powerful buffering system to prevent jumping in the case of vibration. This was included to make MiniDisc suitable for in-car use, jogging, rollerblading, and so on, but it's just as welcome for live performance. Even so, I believe paranoia to be an essential survival trait for live performance, so I'd still stand the player on a foam slab. The disks are about the size of After Eight mints, so losing them is probably just as great a risk as damaging them.

MIDI Files

While many performers buy pre-recorded backing tapes, there is a strong case for using commercially available MIDI files, either to create your own tapes, or to create a 'live' synthesized backing from a General MIDI sound module. Better still, you can create your own if your arranging skills are up to it. The great beauty of MIDI files is that they only contain data, they don't produce any sound on their own, so the sound of the end result can be changed depending on what synthesizer module (or computer soundcard) you use to play the file back.

Perhaps more important is the ability to customise the performance by changing the tempo, or by changing the key of the song, both of which may be adjusted independently. What's more, anyone with editing experience on a MIDI sequencer can modify the song arrangements — for example, to add or subtract verses, or to mute the part or parts that you want to add live.

Unless you have your own MIDI sequencer and synth (or PC with suitable soundcard and software), you'll need to buy your MIDI files, then take them to a MIDI studio to get them turned into backing tracks. Depending on the studio, and on your budget, you can use the files as they come or you can experiment with different sounds and different effects to make your version of the song distinctive in some way.

The alternative to backing tapes is to use a MIDI file player (eg. Viscount's RD800 or MDF01, or the Yamaha MDF2) plus synth on stage. The safest bet is to use a hardware (as opposed to computer-based) system as computers tend not to enjoy a life of travel. There are systems that combine synthesizer and MIDI file player in the same box, and these are very attractive to the performer wanting to travel light. Having tried both approaches in the past, I find having a finished backing tape or disk rather more reassuring as there's less to go wrong. MIDI file players and sequencers can occasionally be disrupted by mains-borne interference, and if you happen to be connected to a sound level cutout, your song will evaporate from the machine's memory if you trip the system.

SUMMARY

Backing tracks are an important part of live performance for a great number of players, but the commonly used cassette machine is less than ideal because of its inherent noisiness and potential for speed errors. Digital tape and digital disc systems are stable as regards speed and have a far better noise performance. Furthermore, the tonal quality of the recording isn't prone to deteriorate with time. Tape-based systems have the inherent disadvantage of the time needed to wind from one song to another, while CD-R is prone to jumping when subjected to vibration or shocks. Whatever other problems tape may have, it never jumps! Hopefully, by looking at the more practical options, and by exposing their weaknesses as well as their advantages, you'll be in a better position to choose a system that fits both your needs and your budget.