Live Sound Mixing Tips

There is a question posted on the comment page on the main site about monitors. This topic deserves more space than I would like to take up as a reply there so I am writing this blog entry to address the question. The text of the question is:

We have a band consisting of 11 musicians and 3 singers, we face the same problem every time when we have a concert with the sound mixer and the monitors, when we test the sound before the concerts it’s fine but in the concert most of the guys can’t hear their voice or their instrument sound – specially guitars, drums and flute – in the monitors so everyone starts to play hard and loud so they can hear what they are playing, and the rest you know …. A TOTAL MESS!!

Since we are beginners in that field I was wondering if you have some useful information or some kind of guidelines for setting the sound, we would appreciate your help.

One more thing is what exactly we should hear in the monitors? All instruments or only bass, drums and the instrument played through that monitor?

The Monitor Requirements

The monitors are really the most important part of the PA system. If the musicians can’t hear they can’t play their best. Making music is a team sport. If the team can’t follow what the other players are doing they can’t be in the right place at the right time.

Many people are too concerned with the main PA and put the monitors as secondary in importance. Depending on the music and the budget the monitor system can be quite extensive. Most major concert artists use in-ear monitoring systems now days. A solo artist or a duo can often get by with a single monitor mix. Bands do also get by with a single mix, but it requires experience and co-operation.

It is best to have separate monitor mixes so that the musicians can hear what they need to hear. For most situations I run three or four monitor mixes. Four mixes would typically be a stage right mix, a center mix, a stage left mix, and a drum mix.

What should be in the monitors?

That will depend on various things. Vocals and any acoustic instruments will need to be in the monitors. Then, those things needed for timing may need to be added. For lead players the timing often comes from the snare drum or high hat. For rhythm section players the kick drum may be important.

It will be easiest to hear what is needed if only those things that are absolutely necessary are in the monitors. If there is too much in the monitors or the things in the monitors are too loud it raises the overall volume on the stage and ultimately makes everything harder to hear. This is part of the reason that multiple monitor mixes can be of help. If a player on the right side of the stage needs to hear what a player on the left side of the stage is doing that can be turned up only in the right side mix, saving the volume that would be added by the center and left side monitors, and vise versa.

Monitor Systems

Each monitor mix should consist of an equalizer for the mix, a channel of an amplifier for the mix (two if bi-amped) and the monitor speaker or speakers. These components should be repeated for each mix that is run. The equalizer is primarily for feedback control. Good monitor speakers should sound pretty good without too much sound shaping but the room can cause some problems as far as the sound. If the stage is not built as well as it could be there may be some problems in the low-mids that may need some correction. Reflections from walls and ceilings may cause feed back problems. The frequencies that are causing problems need to be isolated and cut on  the eq. There is no specific way that the eq should look. The settings on the eq will depend on the speakers used and the environment of the stage. Be careful to cut only as much as needed to clear up the sound and prevent feedback. Cutting too much can damage the sound and make things harder to hear.

In-Ear Monitor Systems

Caution: When using in ear monitoring systems volume control is very important. The monitors are like ear buds that fit within the ear canal. Since there is no place else for the sound to go it is possible to damage your hearing if they are played too loud. There should be some form of limiting on the in ear mix to prevent excessive volume.

In ear monitors have several advantages, but the systems will need to be a bit more complex. The ears can be either wired or wireless. Most people use wired in ears for drums and keys and any players that have a station on stage. Players that move around need wireless systems. Most players will need and individual monitor mix for their ears as well. Background singers may be able to share a mix.

In ear monitors can allow each musician to hear exactly what they need to hear without adding to the stage volume as is the case with conventional monitors. Most people use some sort of ambiance mikes with the in ear system so that there will be some sound of the room and crowd heard.

Conclusion

The monitor system is very important to the performance. In most cases, good monitors will give opportunity to have a good show. Run only the things that need to be heard in the monitors to help contain the volume. Multiple mixes can help because the musician can hear the things that are important to them without blasting the other musicians. With good equipment and experience everybody will be able to hear on stage and the band can truly play as a team.

While we usually associate feedback problems with monitors, reflected sound from the mains can also be a problem. This is more likely in indoor venues, but can be a problem anywhere that has surfaces that can reflect main PA sound back to the stage.

Nearly any surface can become a mirror reflecting sound back to the stage. High frequencies are more prone to this sort of a problem, and they are the ones that are most likely to produce a feedback loop. Flat surfaces common in clubs and indoor venues are the most likely to cause problems, but even rounded objects can cause problems.

Feedback is a sound loop at a specific frequency. The higher the volume the more likelihood of encountering feedback problems. When the microphone ‘hears’ the looped sound louder than the main sound you will probably get feedback.

The solution to feedback is to take the problem frequencies out of the equation with an EQ notch at the frequency causing the problem. Typically a one-third octave EQ is used for this. The problem is to remove the feedback frequency without destroying the sound quality. Apply the minimum amount of EQ to eliminate the problem will help to maintain sound quality.

If the source of the problem can be identified a sound treatment may be in order to alleviate the problem. In some cases a thick pile carpet may help or acoustic foam may be applied. Identifying the source may be difficult as these problems can be transient in nature depending on where things and even crowd is in the room.

Feedback problems can be difficult to deal with but must be dealt with to give a good quality to the show. If you have persistent feedback problems you will need to chase them until you find the best solution for the sound quality and the quality of the performance.