In this blog, Art of Mixing part 2, we will get into a few more of the mixing details that need to go in to the process of building a good mix and maintaining it.
Parametric EQ
The Parametric EQ is the EQ that is set on the actual input channel. This is not to be confused with graphic EQ that is inserted in a channel and is used to notch certain frequencies and is usually configured in either 15 or 31 channel formats.
The most important thing to remember when setting the EQ whether parametric or graphic is to take away – not add. Every frequency on an input is already present. What happens is the frequencies that are desired are covered up by frequencies that are not desired. This is why you want to find the un-desirable frequencies and pull them out. Don’t over do it. Keep in mind every time a frequency is pulled out gain is also being pulled out. Only pull out what you need and nothing more. It is the tendency of many engineers to boost frequencies. Do not do this. There are very few exceptions to this EQ principle.
During a sound check or rehearsal it is safe to boost a frequency for the purpose of helping you find the frequency that sounds bad then pull it down. Remember, don’t pull it all the way out. Usually it is a pretty slight notch.
Gates and Compressors
The use of a gate can be very effective in controlling what is allowed to pass through the system through and open mic. Use a gate on snare drum mic and tom mics. Sometimes a gate on the Kick drum is in order. There are very rare occasions to use a gate on anything other than these mics. Only use a gate if you are familiar on how to set thresholds, range and decay etc.
Compressors are a very effective way to make an instrument or vocal mic stick out in a mix. Do not over compress anything. Light compression is best. If you are unfamiliar with setting compressors then no compression at all is better than compressor that is not properly set. Vocal mics, acoustic guitars, snare drum, kick drum, sometimes toms and speech mics are all appropriate for compression. Don’t compress keys or electric guitars.
Mixing tips
Once the base mix has been established then it is time to begin mixing. A band rehearsal is a great time to practice mixing. Using the pyramid from Part 1, set the kick drum and bass guitar and then build from there. After the drums have been placed appropriately in the mix and the lead vocal is out on the top then the trick to mixing begins not by having everything in the mix at the same time. Rather it is more important to bring instruments in and out of the mix according to what is happening during the song. Treat the soundboard as the primary instrument in the band. As the audio engineer it is important to pay attention to what is going on with the song. Is it an up tempo song? What instrument is driving the song? Are there any instrumental solos? Where is the solo in the song? Is it after the second Chorus? Does the electric guitar intro the song? In addition to asking these questions constantly (about every 10-20 seconds) ask yourself, “What does the song need right now?” Normally, the base of the pyramid and the top don’t change much. The two layers in between are the mixing variables. These are things that will constantly be changing in the mix.
In some situations the quality of the musicianship has to be addressed in the mix. Keep something very important in mind: It is your job as audio engineer to make the mix sound the best it possibly can. So, you will have a singer from time to time singing flat. You have to back that person down in the mix. If you have an acoustic guitar player who cannot seem to find the rhythm, you have to back that person down in the mix. This is nothing personal toward that person. It is simply what needs to be done in order to achieve the goal of good sound.
Volume
The volume of the overall mix is a very delicate issue. It is easy to say that in a typical worship service the volume should sit around 92-94db. However, there are many things to consider while achieving this level. First, understand that SPL meters have a few settings. A and C weightings, fast and slow settings. OSHA rates safe sound levels using the A weighting. The difference in A versus C weightings is C weighting measures full range; highs, mids and lows and A weighting measures only high and mid range frequencies. The reason A is most important is that Low frequencies don’t damage hearing so OSHA doesn’t regulate low levels when measuring safe sound levels. Most churches use C weighting so bear in mind the differences. 94db C weighted will usually read less using A weighting. The best setting for SPL meters is A weighted slow setting. The volume based on SPL meter A weighted that is ideal for worship services is 90-92db with a peak of 95db.
The other issue to address with regard to overall volume is quality of the sound. If the audio engineer has built a full mix with all frequencies well represented then the over all volumes can be louder. If there is too much emphasis on high mid (vocal and guitar ranges) frequencies then the mix becomes more painful to hear the louder it gets. If the overall volume is too soft other issues are encountered. The goal in church sound is to create an atmosphere where people feel welcome to engage in worship. Often times if the mix is too soft people will hesitate to engage and not sing because they are afraid people around them will hear them singing.
During the worship service watch the audience. Are they engaging? Can you hear the crowd singing? This is a sign that the mix is loud enough that people feel comfortable singing and not so loud that you cannot hear them singing.
Hopefully these tips and tricks will allow a great worship experience for your church. This has been a basic introduction in to the art of mixing. Feel free to contact me for more information.