We have divided our sound system into four main parts:
For this lesson we will consider an electronic signal entering our system with the purpose of being amplified or reproduced - an input. This can include anything such as microphones used to pick up vocals or instruments, electronic insertion devices such as direct boxes (DI) or computer interfaces, or playback sources such as video players, computers, iPods, etc.
Most people associate the main FOH mixer as ”the sound system”. However, there may be other less obvious mixer/combiners incorporated within our system. These units may be stuck in a rack back in your equipment closet. This class of “combiners” include matrix mixers and distribution amplifiers (DAs). These units are rarely very fancy or exciting to look at, but can provide very useful functions. A matrix mixer for example can be used to simply “combine” more than one input before passing the signal along to its destination. A DA is more commonly used in association with outputs. Our DA can take a single input, split it to multiple isolated outputs (in many cases with separate output volume controls) to feed more than one power amplifier or even multiple recording devices. Actually, a given system may not have specific boxes to perform these functions. With today’s DSP technology, many of these functions are incorporated into our DSP units.
Let’s look at the mixers most commonly associated with a modern sound system. As stated earlier, the main FOH console which may be either analog or digital. A system may also have a dedicated monitor mixer. This mixer may be manned or simply a mixer which processes signals that feed personal In-Ear Monitor (IEM) mixers (which is the case at our Grants Mill campus). Personal IEM Mixers may also derive their signals directly from the FOH mixer (this is the case at most of the COTH campuses other than GM). As streaming and televised programming has become more common, broadcast mixers are becoming commonplace. A broadcast mixer may be a simple mixer (analog or digital) allowing a few inputs and sub mixes to be managed apart from FOH, or may be a full blown console incorporated in an elaborate “studio setting”. You may also find other mixers in production areas that may simply manage different playback sources (which is the case in all of our COTH permanent campuses).
Analog processing usually incorporates several different pieces of gear. A typical analog processing rack may include a number of equalizers, crossovers or frequency dividing networks as well as compressors/limiters.
Whereas with an analog processed system a lot of rack real-estate is commonly required for the multiple pieces of gear, the new Digital Signal Processors (DSP) may only require a couple of rack spaces. Most modern DSP units have all of the components once associated with a large analog processing system incorporated in a single box. Moreover, these powerful units are cleaner, quieter and provide a flexibility never before available. Most of these units are also networkable and may even be controlled remotely.
Our output section will contain the components necessary to allow our audience to hear the stage performance. These components will include FOH speakers, monitor speakers, auxiliary speakers, IEM, amplifiers and in the case of broadcast an embedding device and/or transmitter.
¶ Inputs / Sources
All these are considered inputs or sources.
- Vocal microphones (wired and wireless)
- Drum kits (live or electronic)
- Electric guitar rigs (amplified or amp emulators)
- Keyboards and multi-track playback devices
¶ Mixers
In this picture are the components associated with an AVID Venue digital console.
- Control Surface
- Front-of-House (FOH) Rack
- Stage Rack
- Digital Snake
Now that we have our audience taken care of, what about our band and singers? We need to provide "monitor mixes" for everyone on stage. These “monitor mixes” traditionally have originated at either the FOH mix position as an auxiliary (aux mix), or from a dedicated monitor mix console operated by a separate mix engineer. In larger systems, the most common origination was a monitor console positioned somewhere backstage. This monitor console might be feeding any combination of stage-fills, wedges, headphones or more recently in-ear monitors. It is obvious that this infrastructure might be cost prohibitive for many venues, especially smaller churches.
So, what is the solution?
Here is the most common method we use today - in ear monitors paired with a personal mixer. In most cases, each person on stage will have their own personal mixer. This affords each person the ability to balance their own mix as they desire. Not only does this allow each person on stage to adjust their mix at will, it also frees up the FOH engineer to place his full attention on facilitating an environment that is conducive for the audience to experience the presence of God.
¶ Processing
In years past it was not uncommon to find several tall equipment racks full of power amplifiers, equalizers, crossover units, distribution amplifiers, and compressors/limiters in larger venues.
Digital Signal Processors (DSP)
This two rack-space DSP unit can replace nearly all of the separate pieces of processing gear once associated with an analog system. In most cases, these units are controlled by a computer. In this image we see both the unit and the computer screen where adjustments are made.
¶ Outputs / Speakers
Here we see the Grants Mill main speaker system. It is comprised of a stereo line array speaker system with additional full range “fill” speakers as well as both flown and stage stacked subwoofers.
This image shows both wedge speakers as well as small ”stage fill” speakers.
Here we have a set of custom IEM molds by 1964 Ears.
Here we have ceiling mounted auxiliary speakers.