Aug
11
Mixing monitors can be hugely rewarding, and working with a stage full of monitor wedges is really fun! However, if you are not in complete control at all times, it can very quickly become a nightmare.
I put forward my own procedure and techniques for mixing wedges, although as with all types of mixing, it is hugely subjective and down to personal opinion. Everyone who reads this article will develop or will already have their own unique method that works for them, and as long as you can operate efficiently, retain control and keep the band happy, no one can say that one technique is better than another.
Monitor Mixing Essentials
In order to effectively mix monitors, you need to be able to hear what each band member is hearing. The only way to do this is to go out and stand in the same spot as them but performers don’t tend to like the monitor engineer upstaging their act, so we have to use a listen wedge, the second best solution.
Monitor World
A listen wedge should be an identical monitor wedge to all the others on stage, positioned for the monitor engineer as they operate the console. If everyone on stage is using pairs of wedges, this means the listen wedge should be a pair too. It also means that all the wedges on stage must be identical. This is a non-trivial matter; if you have a mishmash of wedges on stage, you will find it very difficult to make decisions and you will end up mixing blind. It’s a bit like mixing FOH in an isolated room on a pair of near-field monitors.
The listen wedge should be connected to the ‘monitor’ or ‘cue’ bus on the console, enabling you to switch between monitoring any of the mix outputs or channel inputs by using the PFL/AFL/cue switches. I find it helpful to make sure the ‘cue auto-cancel’ or equivalent function is applied when mixing monitors to prevent inadvertently listening to 2 or more sources at the same time. The listen wedge should not have an output EQ assigned, but you need to hear any output EQ changes you make on any other mix with the listen wedge. This means you should ‘insert’ all your outboard EQs rather than running them ‘inline’.
Even though you have a listen wedge, use the soundcheck to walk around the stage, stand next to the band, listen to what they’re hearing and check they’re happy as this is the only time you’ll have this freedom. Take advantage of it!
You should ensure the monitor position has good sight-lines to the whole stage as communication is key to effective monitor mixing. If the band can’t see you, they can’t communicate any changes they need which leads to frustration. Similarly, you should set up a talk-to-stage (TTS) microphone at the monitor console which is routed to all wedges, allowing you to talk to the band during soundcheck without shouting and flailing arms! Just remember to turn it off when you’re not using it; a switched mic may be handy.
Figure 1 - Cardioid Polar Pattern
Wedge Positioning
A monitor engineer’s job can be hard, delivering skin-peeling monitor volume to a whispering vocalist for example. Of course, we have tools to help us increase the volume while staving off feedback, but the best tool of all is education and good mic/speaker selection and positioning.
Stage vocal microphones typically have a cardioid, hypercardioid or supercardioid polar pattern. Very briefly, cardioid microphones (figure 1) have a wide pick-up area at the front (known as a lobe) and a null at the rear (180°), supercardioids (figure 2) have a narrower front lobe, a very small rear lobe (with reverse polarity) with nulls at 120° and 240° and hypercardioids (figure 3) are slightly narrower still with a slightly wider rear lobe and nulls at 109° and 251°. You should bear in mind that while these definitions are the theoretical standards, microphones in the real world don’t conform exactly to the pattern that the manufacturer’s marketing department decided they should be. Indeed, the pattern will change over frequency, and the line is often blurred between the standards. A good quality microphone will not necessarily have a text-book supercardioid definition, but it will be well-defined and manageable.
Figure 2 - Supercardioid Polar Pattern
Vocal microphone choice should be based on the singers style; a singer who’s lips don’t leave the mic grill for the whole set but requires high foldback levels would benefit from a hypercardioid design for higher gain-before-feedback (GBF) whereas a quiet singer who moves relative to the microphone would be better with a cardioid microphone which will be more forgiving to source displacement due to it’s wider front lobe.
Because of the different location of the null point of these microphones, care should be taken when positioning monitor wedges relative to the microphone. Ideally, the wedge should be placed in the null point of the microphone, which means directly behind for a cardioid mic, or slightly angled in for super-cardioid or hyper-cardioid. Care taken at this stage will greatly benefit you when voicing up.
It’s worth noting that often such choices are out of your hands. Quite often, microphone choice will be dictated by the FOH engineer or singer who may choose a microphone based purely on on-axis sonic quality, and wedge position may be dictated by the band or the stage layout. Keyboard players often like their wedges behind them, the setup lending itself to this configuration, but a vocal microphone in the middle of the keyboard would result in a wedge pointing directly at an on-axis microphone. In these cases, you must do the best you can with the tools and knowledge that you have. This is combat audio.
Figure 3 - Hypercardioid Polar Pattern
Everything in it’s Place
After patching the microphones and positioning your monitors, the first thing to do is to verify that every input is plugged into the right channel on the console and every output is routed to the right monitor.
It is useful to use a pink noise generator, commonly featured on the console, to ‘ID’ each wedge by turning on 1 output at a time and verifying the noise is coming out of the right wedge. If your console does not have a noise generator, you can do this with any sound source, such as a microphone or music source. It is also helpful to mark each wedge and speaker cable with the mix name and number with a piece of electrical tape and sharpie. This is essential on a festival stage where the wedges will be frequently moved around, in order to keep track of what mix is where.
To verify the input channels are correctly patched and operational, get someone to go around each microphone on stage and scratch them or tap them with a drumstick. This will reveal without doubt which microphone is plugged into which input, and reduce the confusion of a spoken voice being picked up by multiple microphones at the same time. For DI inputs, a dynamic microphone with an XLR-TS jack cable can be used to plug into the input.
EQ
The chances are that you will need EQ to make your wedges sound good and free of feedback. There are many points in the signal chain where you can apply EQ, and each position has a different purpose. Generally speaking, the channel EQ should be used to correct frequency response problems with the source and the microphone, the output EQ should be used to correct frequency response problems with the speaker and room and the DSP/spectral divider EQ should be used to correct frequency response problems with the individual drivers, as set by the manufacturer to create a decent, consistent, starting point. Generally, the DSP EQ will not be touched on a gig.
Graphic Equaliser
Following these rules, it may be difficult to decide whether to apply EQ on an input or the output, but experience will tell you what problems are caused by what symptoms. For example, all directional microphones exhibit proximity effect, which results in an overly bassy sound when used close up. This is something that is attributed to the microphone and should be fixed on the channel EQ. Depending on the vocalist and the microphone, I find a high-pass filter set to about 150Hz and a LF cut of 3-6dB at about 200-250Hz will tame this problem. Room problems tend to consist of standing waves and reflections, which should be fixed with the output EQ, frequently a graphic EQ in an analogue system. If you find yourself applying the same filter to every input, consider moving that filter to the output, as it is probably a speaker/room issue.
This may seem to be a trivial issue, but if you apply EQ that is required to fix a microphone issue to an output, this will apply the same EQ to all channels routed to the mix equally. This is fine for the original microphone, but the chances are you will not want to apply the same fix to every other input. It is well worth the effort to get this right, and will help to greatly improve the tonality of your mixes.
Voicing-Up Wedges
The aim of voicing up monitors is to make them sound subjectively good but equally to keep them ‘safe’ from feedback at the required volume. There may have to be compromise in one or both of these requirements in order to fulfil the other.
I have outlined the process I use to voice up monitors in this section. You may find it useful to have a system tech or competent person ‘drive’ the monitor console while you talk into the microphone, listen and call the changes. You can spend the whole gig behind the console, don’t be scared to actually go and listen to the stage when you have the opportunity!
With a simple rock band setup, often the most important thing in the monitor mix is vocals. As a general rule, everybody needs to hear their own vocal, and they have no chance of keeping up on a loud stage without amplification. Vocal microphones are the best way to voice up your monitors, as they are often most prone to feedback, and often need to be the loudest component of the mix.
Set up the vocal microphone to be used at the correct position in front of the wedges. If the performer will be static, there is little point moving it from the position they prefer, but if they are moving, you better make sure that you test it by walking wherever they’re going. Sometimes this is an unknown, and it may be better to play it safe and cover every eventuality.
Set the input gain to an appropriate level and while talking into the microphone, slowly bring up the level in the monitor using the auxiliary send until it just starts to ‘ring’ at a single frequency. If the desired volume is reached before this point, apply any EQ necessary to make it sound good and no more work is required. If not, cut the ringing frequency just enough to stop it feeding back and to keep it clean.
If you are not sure of the frequency, have a guess and slowly push up the frequency you think it is. If the feedback gets worse at the same frequency, then you got it right and you can apply a cut to that frequency, but if it doesn’t get any worse or doesn’t make as much of a difference as it should, then you need to try a different one. As you boost the frequency, you will hear the tonality change and this will give you an indication how far off and in which direction you were. Always return each band of EQ back to it’s previous position if changing it didn’t affect the sound the way you expected.
Recognising frequencies is a hugely important skill for a monitor engineer to work efficiently. You need to hear and remove it before it takes hold. Like everything, this skill will improve with experience, but you need to take the plunge and have a go first. Simple Feedback Trainer is a highly recommended application for PC only which plays back random feedback tones and makes you guess the frequency. This is a great way to start the learning process without annoying everyone on stage with feedback!
Small Stage Monitor World
Once you’ve eliminated the first feedback, you can continue increasing the volume slowly until another frequency starts to ring. Repeat the procedure until the desired level is reached. You should end up with up to 3 or 4 cuts on the EQ to get the desired level. If it is still not loud enough, or you find yourself cutting lots of frequencies by large amounts, you probably need bigger or better wedges!
Remember that you also need to make the wedge sound good, as well as preventing feedback, so if at any point you feel you need to apply EQ for this purpose, do it.
Once you are happy with these settings, you can copy the output EQ to every other output with an identical wedge on, and the input EQ to every other input with an identical input (i.e. SM58 vocals to other SM58 vocal channels). Here you will benefit from using EQ in the right place; you do not want to apply EQ required for an SM58 to every other input in the mix.
You should then go around the stage and verify that each wedge and vocal mic combination sounds good and is safe from feedback. You may need to repeat the process for different mic/wedge combinations or wedge pairs if you voiced up with a single wedge. After you have verified and are happy with every wedge, turn them all on together and go around again, making sure everything on stage is clean, clear and free from feedback.
Sound Quality vs. Safety
You often have to make a decision to make a microphone more prone to feedback in order to increase the sound quality. For example, some singers like to hear an extended high frequency response or ‘air’ which can easily lead to feedback problems. Sometimes this problem happens with volume too, where the performer requires more level than you can give without giving up your safety margin. These are situations where the only advice is to keep an eye on it. If you apply EQ, you lose the desired HF extension. Ensure the mic is not going to feedback in normal use, but watch them, and back it down slightly when they move too close to the wedge.
How to Construct a Mix
Every performer has a different idea of a good monitor mix, so it is up to you to retrieve this information from them. This is sometimes easier said than done!
First of all, you should simply ask what they usually need in their wedges. If they give you a concise list of particular things, then you can go and dial in these things as a starting point. These performers are usually used to working with monitor wedges and separate FOH/monitor engineers, generally know what they want and will tell you. If they reply with ‘a bit of everything’ or ‘a general mix’ or something to this effect, then a bit of educated guesswork is in order. It is not a good idea to give them everything as this will clutter the mix, reducing the clarity of what they actually need to hear and increase the stage volume.
If you are having trouble getting any detailed information, then you should be thinking ‘What are they not likely to be able hear?’ and ‘What do they need to hear?’. A bassist stage left will probably need to hear some guitar stage right unless it is a small stage. They will probably also need to hear kick and snare in order to create a tight groove. Similarly, a drummer also usually needs to hear kick, snare and bass for the same reason. They may not need guitars if the guitar amps are behind the drum riser, and they may not need lead vocals if the lead singer is right in front of the drummer.
As a general rule, I would start with putting everyone’s vocal into their own wedge only, kick and snare into the drum-fill/bass wedge and bass guitar into the drum-fill. Quiet or acoustically silent instruments, i.e. keys and acoustic guitars, will need to be put into the player’s wedge. From this point, you can ask during the course of the soundcheck who needs to hear each instrument while checking it.
Running the Show
In an ideal world, once the soundcheck is finished and the band are happy, you would be finished, time for a beer. Unfortunately, things change. Once the show gets going, they want things turned up, the vocalist’s voice starts to die so needs more level, the stage volume increases along with the potential for feedback. You need to keep your wits about you and you need to keep your eyes on the stage all the time. An inattentive monitor engineer is pretty frustrating for a band.
Conclusion
This is generally the process that I use to mix wedges. You will find that you often don’t have the time to follow the guide to the letter, neither do I, but I have developed a way of working that works for me and gets me repeat bookings based on these guidelines. As a band monitor engineer, use the system tech, get them to operate the console during soundcheck/changeover and other tasks to allow you to do the most important thing which is keeping your artist happy. Whatever you need to do to get there is what you have to do.