Ever borrowed a brilliant tape from a friend, only to find it sounds terrible on your system? Here's how you can avoid risking the same problem when your precious demo reaches a record company fat cat.

LETS SAY YOU'VE laid your hands on a four-track, or even just a mixer and a cassette deck. An instant studio for your music is yours at last. Lovely. Now there's just one problem. How are you going to hear what you're recording? And, ultimately, what you're mixing?

Headphones are an easy and relatively cheap answer, and they do have positive advantages. If you're engineering a complicated mix, you can hear what's going on a lot more easily with a pair of cans (gosh, he knows the lingo!), especially when you're trying to pan accurately — ie. position tracks right and left in the stereo mix. The greatest benefit of headphones is that they isolate the sound from the rest of the room. That makes it much easier to tell whether that funny buzzing noise you can hear is really coming from the guitar, and not just from a kazoo someone unhelpfully placed on top of one of the speakers.

Unfortunately, this is where the problems start. If you make a mix that sounds excellent on headphones, it'll ring true when someone listens to it on a personal stereo, but go down like a ton of bricks when they slam it into their home hi-fi. Then again, if you mix something to sound good on a pair of bassy hi-fi speakers, chances are it won't be much cop on a suburb-blaster. And so on.

In the end, you have to compromise, or you'll be doing a different mix for every possible sound system. And the compromise to go for in monitoring your recordings is an amplifier/loudspeaker combination with the most neutral sound you can achieve.

Any monitoring system works on the principle of getting the purest possible source signal, and converting it into sound with the least possible distortion along the way. In this chain from signal to sound, the signal deteriorates in two ways. First, it loses a certain amount of accuracy - in other words, the fine details of the music. Second, the equipment adds certain characteristics to the sound; for instance, making it appear "full", "bright" or "bassy". This is known as presentation. In a home hi-fi system, you might well choose equipment whose presentation suits the type of music you like. But in monitoring a recording or a mix, you need to find equipment which offers not only accuracy of detail, but also a neutral presentation, leaving the sound as uncoloured and close to the original as possible.

A lot of producers and engineers like to reverse this idea, and check their mix on the sort of equipment they think it will be heard on. They do a preliminary mix on outrageously expensive studio monitors, and then play it through a pair of 3" car radio speakers, to see if it'll "come over" in its target context. Likewise, producers of records aimed specifically at clubs do their monitoring on systems that have the characteristics of dancehall PAs.

It's worth bearing these ideas in mind, but concentrate on a decent neutral monitoring system first.

AMPLIFICATION

SPEAKERS REQUIRE AMPLIFIERS. So let's talk amps. Most domestic hi-fi amps are what's known as "integrated". Nothing to do with integrated circuits or chips (though the amps may well contain some), this term means that they combine the functions of a preamp and a power amp. A power amp is a machine which boosts a signal by a fixed proportion. If a very good signal goes in, a not-so-quiet signal goes out, and if a loud signal goes in, a very loud signal goes out. The confusingly named preamp then takes that boosted signal, and "attenuates" it. (That's technospeak for "makes it quieter".) So a volume control actually works in exactly the opposite way to what you'd think. When it's turned right down, the preamp is attenuating like the clappers. And when it's on full, it's doing next to nothing at all. The more expensive hi-fi systems separate these "pre" and "power" bits into two boxes.

So, you could take a line from your four-track or mixer and plug it into a normal integrated amplifier. Fine. But that means putting your signal through a lot of unnecessary circuitry, which will deteriorate that pure, neutral sound quality you're after. The preamp function isn't needed at all for this purpose, because you control the levels directly from the four-track. Ideally, then, you should try and get a power amp. Alternatively, some integrated amps have a link between the pre and power sections, so that you can bypass the preamp. If so, jump the signal in there. Old versions of the NAD 3020 amp (still widely available secondhand), for instance, have this link. You simply plug into the "Lab In" input, rather than the "Amp In" one. Check with a dealer if you're unsure about what you can plug into what (particularly if you're buying it off them!). If you can't avoid the preamp part of your integrated amp, use the CD input, as it's likely to have the widest frequency bandwidth, and the least EQ.

SPEAKERS

HERE GOES ANOTHER little physics lesson. Hold tight, though — it's worth it. A loudspeaker works like this: an alternating electrical signal coming from the amp goes to a coil placed within a magnetic field. The electrical flow within the magnetic field creates movement. This "voice coil" is linked to the speaker cone, which moves in and out as the current varies, pumping air back and forth, creating different waves of pressure in the air and... sound!

As you can imagine, converting electrical energy into mechanical energy is a pretty inefficient process, so this is the point in the chain at which the most distortion occurs. It's a lot easier to tell speakers apart than amps, so when you're buying equipment, pay a lot of attention to the speakers.

There are two main schools of thought in choosing speakers for monitoring, and these are represented by two speaker types: near-field and room monitors. Nearfield monitors are speakers that sit close in — say, on top of the desk you're working on — while room monitors stand on their own, and act within the room. The difference is distance. Near-field monitoring is the more popular approach, and uses fairly clear, bright speakers for detailed examination. Room monitoring is known as the "pipe and slippers" method, attends more to the sound as a whole, and is favoured by the BBC for classical music. It also entails rather more expensive speakers, so that consideration, as well as fashion, will probably persuade you to take the near-field approach.

There are four factors to think about before you buy speakers:

Bandwidth: How low (and high) can they go?

Tonality: What characteristics do they give the music (eg. bassy, bright)?

Dynamics: How quickly do they react to sudden changes of volume (eg. a snare accent)?

Overall clarity: Do they sound muffled, or open?

If you're after a full bass sound on a budget, go for cheaper so-called "ported" speakers. This means they have a hole at the back behind the bass unit. When you put the speaker near a wall, this kids the bass unit into thinking that it's in a bigger cabinet, so it "pushes" harder. It's a question of quantity rather than quality, though.

Almost as important as your choice of speakers is where you put them. Remember the three Rs: right stands, right height, right angle. As a speaker moves air back and forth, it does it relative to your head. So it's important that the speaker doesn't move about, and that what you put it on isn't going to absorb half the detail. Speakers should be mounted on something solid and rigid, so they don't rock about, and something that's not too heavy, either. Otherwise, when the bass unit kicks, a lot of that energy will be absorbed. Ready-made speaker stands are the ideal thing, but if you can't run to them, you can buy spikes to mount the speakers on a suitably rigid surface. The right height and the right angle are important if you're going to receive the maximum possible high frequency (which is very directional), and if you're going to get a good stereo image. So mount the speakers so that their tweeters are at the same level as your ears, and angle them so that the line of action from the units crosses just in front of your head. (This is a general rule. There are exceptions with some smaller speakers, which can be less strictly directional. And note that some larger speakers which work out in the room need special positioning. Check with your dealer.)

Inevitably, the room you're working in will have a massive effect. If it's sparsely furnished, with a lot of reflective surfaces, it will sound very "live" and echoey, in which case you should avoid very bright-sounding speakers. If, on the other hand, it's full of heavy furniture and Laura Ashley fabric, you may need bright speakers to give you a clear sound. Avoid putting speakers in corners, or you'll get a very boomy sound. And if you have a long, narrow room, don't fire the speakers down the length of the room, because you risk creating "standing waves", with areas of very low and very high bass.

Getting the best out of your monitors is something that requires experimentation. There is no scope for damage — unless you drop the speakers! Play around with positioning. Remember, you're after the most neutral, uncoloured sound, and the room can have a lot to do with achieving this. If possible, buy from a dealer who will lend you the equipment first, or give you your money back (or exchange credit) if you're not happy with the final result.

Finally, if all this sounds completely out of your league, there is a reasonable alternative. Try a pair of "active" speakers. Designed originally to be used with personal stereos, these are simply speakers with amplifiers built in. Just plug them into the mains, take a line or headphone jack into your four-track, and Roberta's your Aunt.

THE FINAL MIX

ONCE YOU'VE GOT your final mix on the four-track, you'll need to make a master copy on ordinary two-track (stereo) cassette. To do it well, you need a three-head cassette deck. On most decks, the functions of recording and playback are performed by one head. A three-head machine separates the two. This has the advantage of optimising each head for the job it has to do.

But the main point is that, unlike two-head machines, where you only hear the signal you're inputting, a three-head recorder can monitor what you're recording as you're recording it, because the playback head is positioned just after the record head. This gives you infinite scope for adjustment of levels and equalisation. For instance, if you're recording very dynamic music, with a lot of highs and lows, you have to get the recording level precisely right. With a three-head machine, you can flick from the input signal to the recorded signal, and modify the latter until the two match.

The motto is this. If you've spent some time (and some money) on your monitoring system, you can end up with a tape that will do your music justice on any system.