Mackie ONYX 4Bus 12. AUX Sends, 13. PAN, 15. Channel Fader, 16. Signal Level LEDs, 14. MUTE

ONYX 4•Bus

down to the lowest note you ever heard. “Peaking” means that the frequencies around the center frequency are less affected by the EQ the further away they are.

12. AUX Sends

These tap a portion of each channel’s signal (pre or post-fader) out to either an effects processor (post-fader) or for stage monitoring (pre-fader). The AUX Send levels are controlled by the channel’s AUX 1-6 knobs, and by the AUX SEND MASTERS knobs [55].

These are more than just effects and monitor sends. They can be used to create stereo in-ear monitor mixes, generate separate mixes for recording, for another zone, or “mix-minuses” for broadcast.

13. PAN

PAN adjusts the amount of channel signal sent to the left versus the right outputs.

With the PAN knob hard left, the signal feeds the MAIN LEFT (and GROUP 1 and 3, depending on the setting of the GROUP ASSIGN switches). With the knob hard right, the signal feeds the MAIN RIGHT (and GROUP 2 and 4).

Constant Loudness

The Onyx 4•Bus PAN control em-

ploys a design called “Constant Loud-

ness.” If you have a channel panned

hard left (or right) and then pan to

the center, the signal is attenuated 3 dB to maintain the same apparent

loudness. Otherwise, it would make the sound appear much louder when panned center.

15. Channel Fader

The fader controls the channel’s level…from off to unity gain at the “U” marking, on up to 10 dB of additional gain.

“U” Like Unity Gain

Mackie mixers

have a “U” symbol

on many of the

level controls.

This “U” stands for “unity gain,” meaning no change in signal level.

Once you have adjusted the input signal to line-level, you can set the controls at “U” and your signals will travel through the mixer at optimal levels. What’s more, many of the labels on our level controls are measured in decibels (dB), so you’ll know what you’re doing level-wise if you choose to change a control’s settings.

16. Signal Level LEDs

These LEDs indicate the channel’s signal level after the GAIN and

EQ controls, but just prior to the channel’s fader. So even if the fader is turned down, you can see if a signal is present.

If you’ve followed the “Set the Lev- els” procedure, the –20 and 0 LEDs should light frequently, the +10

AUX

1

OO MAX

2

OO MAX

3

OO MAX

4

OO MAX

5

OO MAX

6

OO MAX

PAN

L R

MUTE

dB1

10

5

	OL
U	+10
	0
5	-20
10	ASSIGN

201-2

14. MUTE

Press this switch to mute the individual channel. This

LED should light occasionally, and the OL (Overload) LED should not light at all. If the OL LED is blink-

30

40

3-4

disconnects the channel’s signal from all the Groups, the Main Mix, and Aux Send buses (pre* and post- fader). You can still solo the channel (PFL) when the MUTE switch is pushed in.

*If the pre-fader Aux Send’s internal jumper is wired for pre-Mute [56], the MUTE switch will not affect the PRE Aux Send.

ing frequently, the signal is probably distorted from overdriving the input. Either turn down the GAIN control or turn down the signal at its source.

50 MAIN

MIX

60

OO

PFL

%1

0!.

!33)'.

)./54

-54%

&!$%2

).054

'!).

,/7/#54

).3%24

%1

0/34

%1

0/34

02%%1

02%-54%

$)2%#4

02%%1

-54%

!5853%.$ 

/54

).4%2.!, *5-0%2

+./"

0/34%1

0/34

4//!58!3%.$ 

).4%2.!,

3)'.!,

"5350/34&!$%2

*5-0%2

!UXU0RE VS 0OST

02%23)'.!,

4//!58!3%.$ 

"53502%&!$%2

3IGNAL &LOWL$IAGRAM

4//!58!3%.$3 

12 ONYX 4•Bus