6.0 Sound Check and Signal Processing: Good Vibrations
Assistive Listening Devices (ALDs), like In-Ear Monitors (IEMs), helps musicians to hear themselves and their bandmate more clearly by giving them a customized mix so they can play in time and in tune. It covers the features needed for mixing consoles, and onboard or outboard processing.
Signal processing is especially important for IEM users to protect their hearing and to accommodate different spectrums of frequencies that someone might have difficulty hearing, or if hearing too much of a certain frequency is painful or uncomfortable.
Compression is essentially a “volume babysitter.” It is like putting a ceiling on the loud sounds and a floor under the quiet ones. Imagine sound waves as a rollercoaster. Some parts go high (loud sounds) and some dip low (quiet sounds). Compression squashes down the loudest parts (so they don’t crash into the ceiling) and boosts up the quietest parts (bringing them closer to the floor). This creates a more balanced and consistent sound without distortion or potentially dangerous volume spikes.
EQ (Equalization) is like controlling an elevator with three floors. Bass (low frequencies), Midrange, and Treble (high frequencies). You can raise or lower each floor to make the sound more balanced and easier to hear. For someone with hearing loss, adjusting the treble floor might make vocals clearer, while lowering the bass floor could remove muddiness. Since hearing loss can affect how people hear certain frequencies, EQ helps customize the IEM mix to their needs.
EQ comes in two main types: graphic EQ and parametric EQ. Graphic EQ adjusts fixed frequency ranges, like bass, mids, or treble, with simple boost or cut controls. It’s great for quick, general adjustments.
Parametric EQ, on the other hand, is much more precise because it allows you to select the exact frequency to adjust (frequency control), decide how much to boost or cut (gain), and control how wide or narrow the adjustment is (Q, or bandwidth). This makes it ideal for targeting specific problem areas.
Signal processing is especially important for IEM users to protect their hearing and to accommodate different spectrums of frequencies that someone might have difficulty hearing, or if hearing too much of a certain frequency is painful or uncomfortable.
Compression is essentially a “volume babysitter.” It is like putting a ceiling on the loud sounds and a floor under the quiet ones. Imagine sound waves as a rollercoaster. Some parts go high (loud sounds) and some dip low (quiet sounds). Compression squashes down the loudest parts (so they don’t crash into the ceiling) and boosts up the quietest parts (bringing them closer to the floor). This creates a more balanced and consistent sound without distortion or potentially dangerous volume spikes.
EQ (Equalization) is like controlling an elevator with three floors. Bass (low frequencies), Midrange, and Treble (high frequencies). You can raise or lower each floor to make the sound more balanced and easier to hear. For someone with hearing loss, adjusting the treble floor might make vocals clearer, while lowering the bass floor could remove muddiness. Since hearing loss can affect how people hear certain frequencies, EQ helps customize the IEM mix to their needs.
EQ comes in two main types: graphic EQ and parametric EQ. Graphic EQ adjusts fixed frequency ranges, like bass, mids, or treble, with simple boost or cut controls. It’s great for quick, general adjustments.
Parametric EQ, on the other hand, is much more precise because it allows you to select the exact frequency to adjust (frequency control), decide how much to boost or cut (gain), and control how wide or narrow the adjustment is (Q, or bandwidth). This makes it ideal for targeting specific problem areas.
| Feature | What It Needs | Why It Matters |
|---|---|---|
| Inputs/Outputs |
Enough to support all instruments,
microphones, and IEM receivers.
|
Makes sure you have enough connections for everything, especially XLR, TRS, or digital connections.
|
|
Dedicated IEM Submix
|
At least 4 available channels for a separate IEM submix.
|
Lets you adjust the volume and mix for the IEMs independently from what the audience hears.
|
| Signal Processing |
Processors for gain, EQ, and dynamics control on each channel and the submix. A 3-band EQ is a good start while parametric EQ is most ideal.
|
Lets you fine-tune the sound going to the IEMs, for clarity and balance for each musician.
|
| Subgroups/Routing |
Ability to create and route subgroups to both the main output and IEM submix.
|
Flexibility for controlling different instrument groups in both the main and IEM mixes.
|
| Mute Groups/Solo |
Mute groups and solo functions.
|
Makes it easier to isolate specific instruments or groups for quick adjustments during sound checks and performances.
|
| Metering |
Clear, easy-to-read metering for both the main output and the IEM submix.
|
Helps the sound engineer monitor levels and prevent distortion or clipping.
|
| Personal Mixers |
Helps the sound engineer monitor levels and prevent distortion or clipping.
|
Lets musicians customize their own IEM mix, giving them control over their individual sound preferences.
|
| IEM Outputs |
Clear labels and easy access to the IEM outputs.
|
Simplifies setup and troubleshooting, especially when connecting and disconnecting equipment.
|
|
Wireless Interference
|
Systems to reduce wireless interference, like frequency coordination tools or dedicated frequency bands.
|
Makes sure there is a clear, reliable wireless signal transmission for IEMs, especially in environments with lots of wireless devices.
|
IEM System Types
Wireless: These are the most common systems, using radio frequencies to transmit sound. You need to scan for the best channel to avoid interference from other devices. Many IEM receivers have built-in channel scanning for easy setup.
Wired: These are a more affordable option for musicians who stay in one spot, like drummers. A basic setup requires a headphone amplifier with a direct input (XLR or 1/4 inch).
IEM Earbud Considerations
The number of drivers in the earbuds affects the clarity and separation of different frequencies (lows, mids, highs). More drivers generally mean better sound quality, but the cost increases as well.
Wireless: These are the most common systems, using radio frequencies to transmit sound. You need to scan for the best channel to avoid interference from other devices. Many IEM receivers have built-in channel scanning for easy setup.
Wired: These are a more affordable option for musicians who stay in one spot, like drummers. A basic setup requires a headphone amplifier with a direct input (XLR or 1/4 inch).
IEM Earbud Considerations
The number of drivers in the earbuds affects the clarity and separation of different frequencies (lows, mids, highs). More drivers generally mean better sound quality, but the cost increases as well.
