Mackie 1640 User Manual download pdf (Page 10)

ONYX 1640

Onyx 1640 Features

Channel Strips

All sixteen channels on the Onyx 1640

look alike and function identically with

the following exception: Channels 1

and 2 have high-impedance instrument

inputs in addition to the mic and line in-

puts so you can connect a guitar directly

to the mixer.

All the input and output connectors

(except for the headphone jack) are locat-

ed on the rear rotopod. We’ll take a look at

them after we explore the front panel.

1. 48V Phantom Power Switch

Most professional condenser micro-

phones require phantom power, which

is a low-current DC voltage delivered to

the microphone on pins 2 and 3 of the

XLR microphone connector. Push in the

48V button if your microphone needs

phantom power. An LED lights just

above the button to indicate that phan-

tom power is active on that channel.

Dynamic microphones, like Shure’s

SM57 and SM58, do not require phantom

power. However, phantom power will not

harm most dynamic microphones should

you accidentally plug one in while the

phantom power is turned on. Be careful

with older ribbon microphones. Check

the manual for your microphone to ﬁ nd

out for sure whether or not phantom

power can damage it.

Note: Be sure the MAIN MIX fader

[46] is turned down when connecting

microphones to the MIC Inputs, espe-

cially when phantom power is turned on,

to prevent pops from getting through to

the speakers.

2. Low-Cut Switch

The Low-Cut switch, often referred to as a high-pass

ﬁ lter, cuts bass frequencies below 75 Hz at a rate of 18 dB

per octave.

We recommend that you

use the Low-Cut ﬁ lter on

every microphone appli-

cation except kick drum,

bass guitar, bassy synth

patches, or recordings of

earthquakes. These aside,

there isn’t much down

there that you want to

hear, and ﬁ ltering it out makes the low stuff you do want

much more crisp and tasty. Not only that, but the Low-

Cut ﬁ lter can help reduce the possibility of feedback in

live situations and it helps to conserve ampliﬁ er power.

Another way to use the Low Cut ﬁ lter

is in combination with the LOW EQ

on vocals during live performances.

Many times, bass shelving EQ can re-

ally beneﬁ t voices. Trouble is, adding

LOW EQ also boosts stage rumble, mic

handling clunks, and breath pops. Low Cut removes all

those problems so you can add LOW EQ without losing a

woofer.

Here’s what the

combination of LOW EQ

and Low Cut looks like

in terms of frequency

curves.

3. MIC/HI-Z Switch (Channels 1 and 2)

Channels 1 and 2 have an extra button for switching

between the MIC and HI-Z inputs. When the button is out

(MIC), the XLR MIC input is used and the HI-Z input is

disconnected. When the button is pushed in (HI-Z), the

1/4

HI-Z input is used and the XLR MIC input is discon-

nected. The input stage of the HI-Z inputs is specially

designed for the high-impedance pickups on guitars.

Plugging a guitar into a lower-impedance

line input (like those on channels 3-16)

can result in the loss of high frequen-

cies, causing an unnatural and dull

sound. Normally, you must use a direct

box between a guitar and a mixer’s in-

put, which serves to convert the impedance of the guitar

from high to low. The HI-Z inputs on channels 1 and 2

make the need for a direct box unnecessary.

100

10k

20k

–15

–10

–5

+10

+15

Low Cut

20Hz 100Hz 1kHz 10kHz 20kH

–15

–10

–5

+10

+15

Low Cut with Low EQ Boosted

PAN

AUX

SEND

GAIN

FREQ

HIGH

12kHz

HIGH

MID

FREQ

LOW

MID

LOW

80Hz

OUT

8k400

2k10 0

400

+15

MAX

MIC

75Hz

18dB/OCT

+40dB

-20dB

MAX

48V

1 2 ... 5 6 7 8 9 10 11 12 13 14 15 ... 35 36

Comments to this Manuals

No comments

Mackie 1640 User Manual Page 10

Comments to this Manuals

Related products and manuals for Audio Mackie 1640