How To Mix Live Music Chapter 5 - Inputs — Transcript

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1. 0:07Welcome back to the series “How to Mix Live Music”.
2. 0:12Last time we chose our microphones,
3. 0:14and placed them near the instruments on stage.
4. 0:18Now we’re going to bring the sounds from the stage into our mixer,
5. 0:23and make the optimal settings for each input.
6. 0:27But first we’re going to discuss “phantom power”.
7. 0:32This is where the mixing console
8. 0:34sends power back through the cable to the microphone or DI box.
9. 0:39Some mics will stay silent without it.
10. 0:42But before activating it,
11. 0:45make sure the mixer channel is switched off.
12. 0:48Otherwise, you’ll hear a loud popping noise:
13. 0:51could scare children and pets, but it could damage equipment…or ears!
14. 0:57How do you know which mics need it?
15. 1:00Check their specifications.
16. 1:02Basically all “condenser” type of microphones need it:
17. 1:07typical mics used for drum overheads, and sensitive acoustic instruments.
18. 1:13“Dynamic” types do not.
19. 1:16Some DI boxes need it,
20. 1:18while others use batteries, and others still are passive.
21. 1:22So no need for power.
22. 1:24Remember, DI boxes, Direct Injection, are used with instruments
23. 1:30to convert their unbalanced jack connections into balanced signals
24. 1:35for use with longer cables.
25. 1:38Balanced cables are more resistant to interference
26. 1:42from other cables and from radio transmissions.
27. 1:47See at the top of the MGP console,
28. 1:49the small red button is for +48V.
29. 1:53I need to activate this in this example band
30. 1:56for the internal kick drum mic, the Hi-Hat,
31. 2:01drum overheads, and brass mics.
32. 2:06When using the TF mixer, be aware of the +48V Master switch.
33. 2:12It's in the SETUP menu: touch the setup cog,
34. 2:15and see the Master switch in the center of the screen.
35. 2:19This is a safety switch,
36. 2:20to disable phantom power when it is not needed.
37. 2:25Now its time to check the signal level coming in to the mixer.
38. 2:30Each instrument or microphone will produce
39. 2:32electrical signals at different voltages.
40. 2:35They all need to be matched to the nominal level of the mixer.
41. 2:40The nominal level
42. 2:41is the most efficient voltage level for the mixer to operate at,
43. 2:45without distorting the signal and without adding noise.
44. 2:49And a mixer’s nominal level is going to be higher
45. 2:53than that of almost all microphones and musical instruments.
46. 2:57Hence the name “Gain” for the input level control,
47. 3:02which is used to increase the voltage of the input signal
48. 3:05to match the nominal level of the mixer.
49. 3:10Use the PFL button by the fader on MGP,
50. 3:14or the CUE button above the fader on TF.
51. 3:18This will send the input signal to the headphones.
52. 3:23“PFL”, by the way, means “Pre Fader Listen”:
53. 3:27you can hear the sound in the headphones
54. 3:30even when the fader is down and the channel is off.
55. 3:34It also shows the signal more clearly
56. 3:37on the level meter bar at the top-right corner of the console.
57. 3:42Always begin with the headphone level way down,
58. 3:45to avoid sudden loud sounds in your ears!
59. 3:49Then start with the input GAIN control at minimum.
60. 3:53Ask the musician to play the instrument, or sing into the microphone.
61. 3:58Is the level already above 0 dB on the level meter?
62. 4:03If so, push down the 26 dB PAD switch.
63. 4:08This will reduce the input level,
64. 4:10making it easier to match the nominal level of the mixer.
65. 4:15It will be necessary for line level inputs,
66. 4:18such as music playback devices and keyboards.
67. 4:22Then slowly increase the GAIN control while watching the level meter.
68. 4:28When the singing or instrument is loud,
69. 4:31the level should be around the 0 dB point,
70. 4:35which is exactly the mixer’s nominal level.
71. 4:41Don’t be tempted to make it higher,
72. 4:43as it will then become more difficult to mix many inputs together
73. 4:47without overloading the mixer's outputs!
74. 4:52On the TF console, it’s a little different: there is no need for a PAD switch,
75. 4:57because the analog gain, or A.Gain, adjustment has a much wider range.
76. 5:03On the screen, there is another very useful feature:
77. 5:07from the home screen, touch an input’s Gain control,
78. 5:12to see the INPUT screen.
79. 5:14Here we can see the “GainFinder”.
80. 5:17It looks a bit like a guitar tuner,
81. 5:19but instead of showing pitch, it shows signal level.
82. 5:24Adjust the A.Gain using the TOUCH AND TURN knob or dragging on the screen
83. 5:30until you find the point where the central green light
84. 5:34is showing most frequently.
85. 5:38For many vocal microphones,
86. 5:40I expect that point to be somewhere between +30 and +40.
87. 5:46For other instruments it would usually be lower.
88. 5:50The central green indicator lights up
89. 5:52when the input signal is matching the nominal level of the mixer.
90. 5:58If you are using a DI box between an instrument and the mixer,
91. 6:02that will often convert the signal from line level to mic level,
92. 6:06and you may need to apply more gain.
93. 6:10So use the CUE or PFL button
94. 6:13and listen to the sound in the headphones, one channel at a time.
95. 6:19If there is a buzzing sound at the input, try to find the cause:
96. 6:24If a DI box is used,
97. 6:26they often include a “Ground Lift” or “Earth Lift” switch.
98. 6:30Activating it may stop the buzz.
99. 6:34Otherwise, try changing the cable in case it is damaged,
100. 6:38or change the route the cable is laid,
101. 6:41in case it is picking up interference from adjacent power distribution.
102. 6:45These are the most likely causes of noise.
103. 6:51TF consoles have another useful little feature
104. 6:54which is not found on MGP mixers.
105. 6:57It is the Polarity-reverse function,
106. 7:00represented by the small Greek “Phi” symbol.
107. 7:05You will only need this
108. 7:06when you have two microphones for the same instrument
109. 7:09such as “Snare Top” and “Snare Bottom”
110. 7:13or “inside Kick” and “Outside Kick”.
111. 7:18So when you have both a microphone for a guitar cabinet
112. 7:21as well as a direct injection from the instrument, there's another example.
113. 7:27Such techniques are often used
114. 7:29to provide a more detailed and versatile character to the sound.
115. 7:34Anyway, the sound waves picked up by one mic
116. 7:38could be radiating in a different direction to the sound at the other.
117. 7:42So the two combined may not sound so good.
118. 7:46Listen to both channels together in the headphones,
119. 7:51and try activating the polarity switch for one of them.
120. 7:56If the combined sound is improved, keep the polarity reversed.
121. 8:02Now if you look on the right side of the screen,
122. 8:06you will see the level meter that the central green indicator here
123. 8:11corresponds to a level of -20.
124. 8:15Notice that this scale is quite different to that on the analog mixer.
125. 8:20In the next video, I’ll explain about these differences,
126. 8:24and I'll give you some tips
127. 8:25about how to manage the gain structure of your whole sound system.
128. 8:30This is vital for creating a good sound,
129. 8:33no matter whether the performers are being loud or quiet!
130. 8:38See you again soon.