In this second episode, Ben Duncan interviews three pilots in the cockpit of the monitor desk. ANDY SALMON recently returned from Passchendaele II (aka Glastonbury Stage 2) where he mixed the Poison Girls and 29 other bands in 36 hours. PAUL SAMUELSON (now retired to running his own studio in central London) did four supports a night at the Venue and the Brixton Ace in the late 1970s, then mixed on tour with the UK Subs, Funkapolitan, and Millie Jackson. JOHN NEWSHAM is a director at Turbosound Rentals and assists in TFA's management, but rather than "fly a desk" (1940s pilots' term for bureaucratic post), he prefers to be on the road, having a penchant for live sound mixing. People who agree include Roger Walters, Kool and the Gang, Judie Tzuke, and Styx.

Desks

The first step into more elaborate monitoring is the acquisition of a dedicated monitoring console — yes, that's another mixer, lads, up on stage. (The humpers nod, and trudge on wearily.) Having scored a desk, the scope for individual mixers is opened up — perhaps even enough for the whole band.

Andy: "A monitor desk is a different animal to the front-of-house (FOH) console. Usually there are no faders on the channels, but it has extra auxiliary sends instead. The exceptions are some Soundcraft and Soundtracs desks. The monitor desk may have six, eight or more groups, a typical configuration being the BSD 20-8, a real workhorse."

Paul: "The BSD 20-8 is the best basic monitor desk. There's also a Solo facility, so the monitor person can route any one channel into the monitor beside him/her. There's EQ on the inputs and outputs. So the wedges, sidefills, and drumfills can all be EQd individually, for the best sound, and quite separately to the input EQ for the mikes and instruments. Naturally, this avoids the extra cost of four (or more) graphic EQs. Also, I like consoles with a three-way toggle switch, that's ON-OFF-PFL. Then if something howls or if anything else goes wrong, you can soon turn off each suspect channel for a moment, to test the effect and find the fault quickly."

John: "There's been an escalation in just a few years: eight output groups on a monitor mixer used to be considered amazing. I used the first ever board with 12 output groups in 1979, the Amek M500. Now TAC/Amek and Soundcraft are doing models with 24 outputs."

Andy: "If the monitoring console is big enough to match your needs, you should be able to assign one output group to each individual musician, and, similarly, freely direct any (input) channel to any output group. Most desks have some sort of EQ on the outputs, but it's usually quite primitive, relative to the channel EQ. One exception is the TAC/Amek designs, where I've found the EQ good enough to make graphics unnecessary — even when mixing Misty In Boots."

Practical EQ-Tips

Andy: "Obligatory on most monitor systems is a rack of graphic equalisers, usually ⅓rd-octave, 27- or 31-band equalisers. These are either inserted in the output groups of the desk or between the outputs of the desk and the amplifiers driving the monitor speakers. The advantage of a 27-band is that feedback can often be traced to one or two spot frequencies which can easily be cut without drastically affecting the sound."

With input channel EQ, the monitor desk is used mostly to tune up the sound of the instruments, as in FOH mixing. The output EQ, meanwhile, is used to tailor the response of individual mixers to the band's requirements, and to tune out response peaks as and when they become troublesome. If you're wealthy, this latter function can be conveyed to a more elaborate rack-mounting graphic or parametric EQ.

John: "EQ is a characteristic of the particular desk maker. For me, a decent EQ is a four-band parametric. But (laughs knowingly) not everyone can cope with that. I wouldn't want to use it a lot: I'd hope that my 'acoustic compensation' would do most of the work for me. But there's nothing worse than wanting to EQ and not having the frequencies on the mixer. An alternative is to leave the graphic and instead plug a simple parametric into the outputs to soup up the mixer's own, basic, output EQ."

In a big rig, it's normal to have a ⅓rd-octave graphic, the sort with 27 knobs per channel, for each output group. The most popular pro model is the Klark Teknik DN27 because it's relatively cheap. If pushed for rack space, you'll understand why the big hire companies make extensive use of the Court GE60 which packs 27 bands in stereo (ie two channels) in the same three rack unit. But what of this "acoustic compensation" that John spoke of?

John: "Miking technique is very important. Not only using the right mike, but placing it so you can get by with the minimum amount of EQ. Any EQ you have to apply to force the monitors into sounding 'right' just screws up the quality of the out front sound.

"Set up the monitors first, before the main PA. This avoids you having to compensate for the monitors in the FOH. For example, you might get a really boxy kick drum sound coming off the drumfill. This may not be apparent on stage — the drummer hears what he wants. But out front, in the audience, without the main PA, all you hear is a boxy sound with 100dB-plus of 60Hz and 125Hz. And if you haven't sussed that this is what's going on when mixing out front, you could EQ the kick drum for days.

"Good results happen when the monitor engineer 'pink-noises' the monitors at the location where each musician stands." (In other words, pink noise is used to equalise the system flat, relative to where each mike is situated.)

Wedges'n'fills

Stage monitoring speakers come in three basic formats. The WEDGE is primarily for vocals, but the bigger models (with 2x15" drivers) will cope with bass and full blown percussion. SIDE-FILL monitors are typically full-range cabinets or mini PA stacks, being derived from the out front PA. Sometimes they're actually older PA cabs no longer respectable for out front duties. They're turned to face across the stage from each wing, and have a variety of applications. DRUM- and KEYBOARD-fills are specialist fullrange cabinets with two, three or even six drive units tuned explicitly to be intelligible in the midst of very high sound levels.

Andy: "Some PA hire companies still put out wedges containing only a cone speaker which can be quite acceptable for a folk or trad-jazz band who play very quietly and need only a smattering of monitoring. But these wedges tend to feed back very easily when you try to get any real vocal level out of them. This is mainly because the cone driver starts to lose sensitivity in the frequency range where most of the vocal's intelligibility is contained. Remembering clarity, power and quality, wedges generally need some sort of compression driver to give any life to a vocal sound. This is not necessarily an expensive thing. I've seen wedges containing one 12in speaker and a cheap Celestion or Fane bullet, giving a very acceptable vocal sound. They tend to be a bit limited in their power handling, particularly when we've put more than just vocals through them. I once used a pair of wedges containing one 15in speaker and an RCF TW101 — very peaky response and can sound very harsh at times. While these were fairly large and not particularly pleasant-sounding, they were loud and clear. Drummers in particular liked them.

"The most common configurations are 2x12 plus horn and 1x15 plus horn. Obviously, the more you can afford to spend the better quality the drivers will be, and so a smoother response. This fact is quite important when stage volumes start to rise. Feedback usually occurs first where there is a peak in the response of the speakers. Therefore, the smoother the response of the speakers, the less is the chance of feedback and the need for drastic expenditure on graphics to remove peaks. Also, the less you have to tamper with the sound, the better quality the sound will be."

John: "The best wedges I've heard have been two-way (that's with one or more drivers covering the high and low notes respectively). My ideal wedge is one with 2x15 drivers and a horn with a 2in throat. It's good to make use of natural bandwidths and resonances when tailoring the system. For example, the fundamental frequency of female vocals and the guitar is 160Hz, with harmonics up to 2kHz. This is exactly the range covered by a classic 12in speaker, so I'd prefer to use a 2x12 wedge for those particular instruments."

Paul: "If you've insufficient wedges — for example, you're doing a brass section in a hurry — just spread out the available wedges as much as possible. These musicians will be skilled and confident, regardless of how good or lousy the monitoring equipment."

John: "There are loads of theories on sidefills. Some people use them just for vocals, or for drums, while others put through a full mix. For rock'n'roll it's common to 'crossfire' — that means the stage-left guitarist comes out on the stage-right sidefill, and so on. Funk, R'n'B and soul bands tend to play in a fashion which relies either on lead vocals, or what you might call 'rhythm backups', kick drum and snare. So the sidefills end up with those elements, and maybe some bass too."

Andy: "Or we could look on the sidefills as the vocalist's way of getting a backline."

John: "I've usually found that the sound is much more controllable when there's no sidefills. In fact, the best monitoring system is no monitor system at all. That's a stupid thing to say, but there's definitely a law of diminishing returns. The louder the monitor vocals, the more difficult it is to get a natural out front sound on the voice. And drum monitors can absolutely ruin the sound of the drums. Often it seems that the actual sound of the monitor mix going down the mike is louder than the original sound itself. This happens when the sound from a wedge reflects directly off the vocalist's face and into the mike, putting a hard edge on to the sound — that's very hard to get rid of. If you can take away the hard edges on the sounds on stage you can avoid the escalation of monitoring levels. Really, there's no point in getting a good FOH PA together until you've mastered a good sound on stage."

Paul: "Large stages give separation (between mikes and speakers), vital for overall sound quality."

'Directivity' makes a good monitor cabinet. It will spread the sound over a relatively narrow angle: for example, the bullet horn common to many wedges projects a conical beam, like a flashlight, whereas an out front horn array is more like a tar sprayer. By focusing the sound, less power is needed to achieve a given sound level and, of course, less sound escapes out sideways where it's not welcome. This angle is particularly important on sidefills, but only at gigs with small stages where the audience may be unfairly afflicted by sound spraying out the side of the typical sidefill's radial horn. For bigger acts, the greater stage heights (up to 12 feet) and distances make this less of a consideration, and sidefill dispersion may be wide-angle to fill a big stage.

The Job

Andy: "Being a monitor engineer is usually held to be the worst and most thankless job of all. The basis of the job (making sure that the musicians on stage can hear what they need to hear clearly and at the right level to enable them to play) immediately raises two problems. First, the monitor man has to diplomatically get the musicians to distinguish between what they would like to hear and what they actually need to hear. Less professional bands, on seeing an onstage monitor mixer, feel it necessary to make maximum use of every facility in sight. In trying to sound professional, they'll airily say, 'Oh, just give me a bit of everything,' which invariably ends up with the everything-louder-than-everything-else syndrome, which in turn results in lots of feedback, much cursing, and an irate FOH engineer demanding that the monitor levels be turned down as they're interfering with the sound he's trying to get. At this point the monitor engineer either tears his hair out or seeks refuge in yet another bottle of tequila or some other dark medical substance.

"A boring problem facing every monitor engineer is that, unlike the FOH engineer, you cannot hear the results of your work. It's what the musicians actually hear, so you have to be guided by the musicians throughout the show. This obviously creates problems because only certain items of sign language are universally understood... the best guideline for the budding monitor man is summed up by the comment seen written on a monitor desk belonging to a major London PA Company: 'You ain't out front, so don't try to mix it, pal...' Not a lot of scope for subtlety there. Another problem arises if the band plays badly or the audience doesn't like them. According to most musicians this is invariably the soundman's fault — and who's the nearest one to hand? Well, yes, the monitor engineer, so guess who gets it in the neck?"

And if the band are going down well? Well, in this case the howling drunken mob (sometimes referred to as The Audience) decide they want to be on stage. As they invade the stage the only people left to drag them off are... yes, the monitor engineer, and possibly the band's backline crew. By this time the managers, promoters and assorted liggers have all fled to the bar to congratulate themselves on a brilliant gig. This is an awkward situation for the monitor engineer and backline crew, since it's to their benefit to keep the gear in good order. But is it worth risking life and limb? It's really no choice.

The Artistes' role

Andy: "Generally speaking, it should be the musician's responsibility to make sure that the engineer knows what is needed. Many musicians assume that monitor engineers have some strange, psychic, mind-reading powers, and they get quite upset when they find out that they have to tell the engineer what they want. In general, the fewer and the less different the things you try and put through the monitors, the clearer the sound will be."

Paul: "There's an ignorance amongst musicians of the problems and trade-offs faced by the sound engineer. I've had careless musicians wanting their wedges far too loud. Why? Because their backline cabinet was pointing in the opposite direction. Solution? Turn cabinet, so it faces the player. He'll then complain 'That's far too loud.' Because there's a lot of politics, a lot of people with a chip on their shoulder, you have to be quite a diplomat. I used to suss musicians out, guide them and nurture them whenever I had a chance. HM bands in particular have a responsibility to see that their manager doesn't upset the PA engineer."

Sign language

Paul: "When I first did the Four Tops at The Venue, vocalist Laurence kept waving his mike at me. I panicked and switched in his PFL to check his monitor sound. Then after a couple of gigs, I asked what the problem was. 'Oh, it's just the way I dance,' he replied. There's not much standard sign language — but most musicians know how to nod their head to one side to alert the engineer to a mike that's fallen over. In my experience, foreign musicians are particularly prone to exotic sign language. Then there are Rastafarians who speak perfect Oxford English when they're happy, but when they get pissed off, they'll snarl at you in Rasta lingo. When there was a little dissatisfaction at my monitor mix on the Sly'n'Robbie tour, I said firmly but politely, 'Sorry Robbie, we've all had a hard time, please, I don't understand you.' This is how you learn to talk to musicians, to respect their little idiosyncrasies. How to be a rock'n'roll diplomat!