Sound Equipment: Part 2
| Site: | QSC |
| Course: | House of Worship Audio Training |
| Book: | Sound Equipment: Part 2 |
| Printed by: | Guest user |
| Date: | Thursday, 21 November 2024, 8:51 AM |
Description
Lesson Description
In this lesson we discuss source equipment and capture tools that one is likely to find on stage, ie. Cables, stage equipment, microphones. We’ll also discuss basic audio terminology.
Video Transcript
00:15
Ok, now that we’ve covered cable types, let’s look at some capture tools.
00:21
We’ll start with microphones.
00:24
Microphones capture sound waves and convert them to an electrical signal.
00:29
Microphones use either a balanced cable with an XLR connector or a ¼ cable, depending on the microphone.
00:37
We usually refer to the word microphone as Mic.
00:41
There are 2 primary types. Dynamic mics and condenser mics.
00:46
A dynamic mic can withstand high sound pressure levels or SPL’s as it’s often abbreviated , without distorting.
00:55
So, these types of mics are great for kick drums, snare drums, guitar amps,
01:01
and they sound good on vocals as well.
01:04
Dynamic mics are fairly rugged and able to withstand some of the abuse that comes with the live sound environment
01:11
like lead singers using the mic as a drum stick).
01:16
There are different varieties of dynamic mics available,
01:20
some designed for use with instruments and others designed specifically for use with vocals.
01:26
Dynamic microphones are very common in stage performances of all kinds.
01:31
Our second type of mic is the condenser mic.
01:35
The key point to remember with a condenser mic is that they require phantom power, typically +48v, in order to function.
01:43
If phantom power is not enabled on the channel it’s plugged into, the mic will not work.
01:50
When troubleshooting a dead condenser mic, 90% of the time someone forgot to turn on phantom power.
01:58
Phantom power is a charge that runs backwards, from the mixer to the microphone,
02:02
via the same XLR cable that the microphone uses to send signal to the mixer.
02:08
It might seem crazy that power can run over the same cable that also has an audio signal running through it,
02:15
but it works so flawlessly that it is indistinguishable. Hence the name “phantom power!”.
02:22
Though phantom power can range anywhere between 12 and 52 volts,
02:27
48 volts is the most commonly used voltage which is why the phantom power button on your mixer will be labeled 48v.
02:36
Condenser mics are more sensitive than a dynamic mic.
02:39
They generally have a wider frequency range than a dynamic mic, especially in the high end.
02:44
This makes condensers better on cymbals, some stringed instruments, and some vocals as well.
02:45
Condenser mics don’t handle high SPL’s as well, like those from a kick or snare drum,
02:51
but some condensers are equipped with a PAD switch that gives you the option to attenuate
02:56
which means to turn down the signal, making them more functional with high SPLs.
03:02
Condenser mics are often used on hi-hats, cymbals, light percussions like shakers, piano,
03:10
strings, choir, or ambient room mics .
03:14
This should be done with a bit of caution however
03:17
as condenser mics on a loud stage can create problems if not managed properly.
03:23
Next on our list of capture tools is the direct box. We often refer to these as DI boxes.
03:30
Which stands for direct input, or simply D.I.
03:34
D.I.s are often used with acoustic guitars,
03:37
electric guitars, bass guitars, keyboards and virtual drum kits.
03:42
This is a device that converts an unbalanced high impedance signal into a balanced low impedance signal.
03:50
OK, I’ve already lost you. So, simply remember this:
03:55
When connecting an instrument cable to a sound system
03:58
you must go through a direct box.
04:01
Instruments like guitars, bass or keyboards
04:04
produce what’s known as a high impedance signal.
04:08
In addition to being high impedance,
04:10
it is also an unbalanced signal, which we talked about earlier.
04:15
A mixer or a microphone preamp is designed to accept a balanced low impedance signal, which is characteristic of a microphone.
04:24
Impedance is simply referring to the resistance of an electrical signal over the line.
04:31
A direct box converts the signal from an instrument so that it is compatible with the input of a mixing console.
04:38
Without this conversion, you could end up with inconsistent signal levels and unwanted noise in the overall system.
04:46
We’ll discuss all of this more when we start to get all of our equipment setup.
04:52
Now, let’s talk about monitoring.
04:54
Up on stage you will generally see some loudspeakers that are designed to sit on the floor and face the ears of the singers and musicians.
05:02
These are called “floor monitors” also known as “stage wedges.”
05:07
The purpose of these loudspeakers is to provide a means for performers to hear themselves
05:11
and other band members so they can play together comfortably
05:15
and hopefully stay in turn and in time.
05:18
Another type of monitoring you’ll see are In-Ear-Monitors,
05:22
often referred to as IEMs or In-Ears. These are worn like a headphone earbud.
05:30
So, these are the common pieces you’ll find on a stage and the terms used to describe them.
05:36
Of course every stage, and every sound system is different
05:40
and can vary greatly from one day to the next,
05:44
but despite the setup or arrangement,
05:46
you will usually be receiving sound into the system from either a microphone or a direct box.
05:53
Now that we’re familiar with some of the tools used to create and capture sound waves,
05:59
let’s go to the next video and find out how signal flows through a sound system.