The last time we talked about the business of putting sound on tape, the question of using sound-on-sound techniques for 2- to 4-track set-ups was raised. We even gaped, nay, applauded at the prospect of Marvellous Multitrack. Well now, from the magazine that delves deepest, we enter the racy, glamorous world of the 8-track. No more sound-on-sound as a prerequisite to complex recording, dear me no.

One inescapable fact about 8-track recording is that you must have an 8-track stereo mixer to use the medium properly. Sounds obvious? Well, on a 4-track machine you can often fudge the result on a small mixer — and a small mono mixer at that — by track bouncing so that one side of the final stereo mix has one instrument or voice more than the other. Suffice it to say that an 8-track is the first proper rung on the multitrack ladder (for reasons discussed in the February article), and should be used as such. To not do so would represent the same heresy as running a Rolls Royce on paraffin — the waste of a good investment.

So first, let's distinguish once and for all between true multitrack recording and sound-on-sound techniques — and clear up a bit of jargon in the process. Figs 1-4 show, very simply, the different ways of recording several channels of sound on a tape. Only two tape tracks are shown in each case to illustrate the point.

Fig 1 shows a multi-microphone 'live' recording arrangement — which after all is still the original way of recording several channels of sound — while figs 2 to 4 show processes relying on a pre-recorded tape track.

Sound-on-sound

The sound-on-sound configuration shown in fig 2 is the mainstay of the 2- to 4-track recording we discussed in the February issue. The technique allows a composite sound to be built up in tracks, in a mix-as-you-play fashion. An advantage is that the pre-recorded track is replayed via dedicated replay head and electronics, thus optimising quality — but a serious disadvantage is that the new track, comprising pre-recorded original plus 'live' extra vocal or instrument, suffers a delay from the original. So the prime benefit of the multitrack recording — the ability to postpone mix decisions until after recording — is lost. For truly multitrack work therefore the sound-on-sound method can be forgotten about, and it won't be mentioned again.

Overdubbing

Fig 3 shows the basically simple process of overdubbing. Here, pre-recorded tracks are replayed via those tracks' record heads (which you will remember are more commonly called sync heads in the multiworld) and the fresh track recorded in synchronism. Clearly tracks on the tape can be mixed together as required after recording; mixing-as-you-play is not essential. Having said that this method is basically simple (as all tracks are independent of one another), some complexity does arise in the monitoring of the pre-recorded tracks, and that will be discussed later.

Track bouncing

Fig 4 shows track-bouncing, a technique used in multitrack to release tracks on a tape for further recording. A typical example would be the 'squeezing' of several backing vocals — whose relationship to one another can be set at an early stage — down to a stereo pair. The tracks are replayed from their sync heads, mixed and re-recorded across two tracks as they will appear in the final mix. The component backing tracks can then be erased, making way for fresh recordings.

'Track it'

Whenever you hear this customary studio expression, normally prefaced by the suggestion, 'Lets', you know posterity beckons and the sequence you just spent the last hour perfecting is actually going on tape. So what happens when at last the engineer decides to entrust your musical attempts to tape? And why can it sometimes seem to take so long, even in an efficient studio? To answer these questions we must look at the operating modes of the mixing desk, and in particular the all-important monitoring chain, which can take time to set up correctly. Let's take an 8-channel mixer as an example. Table 1 shows the basic inputs and outputs and figs 5-7 the way they are used.

Foldback

Several mono foldback outputs are provided so that each musician gets a rough mix best suited to individual needs (on cans); getting this right can take some fine adjustment. Some large studios provide several different foldback feeds, sometimes in stereo, each mixed to suit on the desk. Others send a small number, say four, of pre-mixed (nothing to do with musique concrete) foldback channels for musicians to mix together for themselves, on their foldback sockets. This can simplify matters until you get a musician who can't operate it. At the opposite end of the scale is the simple stereo (or even mono) single foldback feed which every musician listens to — this is a compromise, but it's cheap!

Recording mode

Fig 5 shows the mixer in recording mode. Adjustments for sensitivity and eq (frequency emphasis or de-emphasis) - plus a load of other processing and patching facilities on sophisticated consoles — are carried out on the input section. This houses pan and fader controls. Just to confuse things, monitor and foldback is sometimes taken after the pan pots and faders — but this is not shown in the diagram. In addition, large mixers frequently have more input channels than output channels, in which case inputs have to be routed to output channels — but again fig 5 omits routing switches for simplicity. The eight outputs go directly to an 8-track recorder.

Overdub mode

Fig 6 shows two microphone signals being overdubbed. There could be more or fewer inputs, which need not be microphones but rather guitar, synthesiser and what have you. Sync head outputs are brought up on channels 3 to 8 and used for rough mix monitoring and foldback only, in conjunction with the new inputs. Meanwhile the new inputs are recorded on to tape, in this case tracks 1 and 2.

Mixdown mode

All necessary components of the final sound have now been assembled on tracks of multi-track tape, and the only thing to do now is exploit multitrack's main advantage — mix it all together in a separate operation. Obviously replay rather than sync heads are used for this as they are designed specifically for the purpose. Frequently, ancillary equipment — phasers, compressors, delay devices — are patched to particular input channels. All output channels are routed to group mixer modules which produce the required stereo master output. The monitor system takes its feed from this master output. Foldback is redundant.

Solo

There are occasions during the setting up of a mix when tracks may have to be monitored individually to check eq or quality. Some consoles have a 'solo' facility which enables you to exclude all tracks from the monitor section input except that particular track at the touch of one button. Thus solo gives you post fader level of one track (in stereo) and mutes all other tracks to the monitor. It does not affect the master output to the mixdown recorder. Most small 8-channel mixers of the Teac and Turnkey variety do not offer such refinements, to keep the cost down. But it is possible to achieve similar results with some external switching matrices. Foldback and monitor facilities tend in general to be rather rudimentary on low cost mixers, but add-on modules are available for most of these. A significant factor in the cost of expensive consoles is the provision of switching and patching facilities, with their associated buffer/mixer amplifier circuitry. If you don't need sophisticated patching options, you can very often save money by opting for the modular approach.

Next: Making the most of a multitrack desk.