Mackie lm3204 User Manual

In keeping with the stereo theme of this entire

mixer, the engineers at Mackie have decided to
provide stereo equalization as well. Just like the
stereo Gain control, the EQ knobs have both left
and right EQ sections ganged on a single shaft.

The LM-3204 EQ has three sections, each

with a fixed knee or center frequency and
bandwidth. Frequency curves are shown below.

The low-frequency equalizer 

 is a shelv-

ing EQ with the knee of the shelf set at 80 Hz.
The Lo section offers a swing of 

±

15dB.

The mid-frequency EQ 

 is a peaking EQ,

featuring a bell-shaped peak/dip curve cen-
tered at 2.5 kHz with a smooth-sounding
2-octave bandwidth. The Mid section can cut
or boost over a range of 

±

12dB.

The high-frequency equalizer 

 is a shelv-

ing EQ with the knee of the shelf set at 12
kHz. Like the Lo section, the Hi section offers
a swing of 

±

15dB at a very useful frequency.

When any of the EQ knobs are set at their

“Unity” detents, that section is effectively out
of the circuit.

The LM-3204 offers 4 separate sets of auxil-

iary sends from each input module. Two sets
of sends per module can be selected at any
one time. The Shift switch 

 allows you to

choose either sends 1 and 2, or sends 3 and 4
on any channel strip.

Sends 1 and 3 

, selected alternately by

the Shift button, are true stereo sends with
left and right channels maintained separately
throughout the auxiliary send circuitry.

Sends 2 and 4 

, also selected alternately

by the Shift switch, are mono sends. Within
each channel strip, the left and right input
signals are combined into a mono sum for
sends 2 and 4, which appear at their output
jacks as monaural signals.

All the sends on the LM-3204 are post-Gain

control, post-EQ, post-Mute switch. Unfortu-
nately, due to the incredibly dense surface
mount circuitry inside this beast, modifica-
tions are not possible.

Each AUX send control has a “Unity” de-

tent at the top of its travel, and, like the rest
of the mixer, will deliver a “level in = level
out” signal at the send outputs when set to
“U.” Setting the aux send controls fully clock-
wise delivers a whopping +15dB of gain.

The Master Output section is that right-hand

one-fifth of the LM-3204 we promised we’d talk
about earlier in the manual. This section is
home to the Master Faders, Control Room,
Headphone and Solo level controls, the AUX Re-
turns and, of course, the Rude Solo Light.

The mix level of the main Left and Right

buses is controlled by the Left and Right
Master Faders. The unity gain point for the
mix output circuits is marked with a “U,”
with 10dB of gain available beyond that
point. When both channel strip Gain and
the Left and Right Master Faders are set at
unity, the output level of the LM-3204 will
be the same as the input level.

Above the Master Faders are the Left

and Right Meters. These are peak averag-
ing meters, with zero (0)dB referenced to

±

±

±

U

+30dB

O

O

BALANCE

L

–15

+15

U

–12

+12

U

2

+15

O

O

U

–15

+15

U

1

+15

O

O

U

16

SHIFT

-20

OL

4

3

12k

STEREO

MONO

HI

80

LO

2.5k

MID

EQ

SOLO

AUX

L

R

16

CHANNEL

MUTE

ALT 3-4 

GAIN

GAIN

10

22

+20

O

O

U

1

LEVEL

+20

O

O

U

2

+20

O

O

U

3

LEVEL

+20

O

O

U

4

STEREO AUX RETURNS

AUX RETURN 

TO CONTROL 

ROOM ONLY

SOURCE

ALT 3-4

40

30

20

10

7

4

2

0

2

4

7

+

–

CLIP

PHONES

O

O

SOLO

+20

O

O

U

TAPE

MONITOR

LEVEL

POWER

LM-3204 STEREO LINE MIXER

,,,,,,,

,,,,,,,

,,,,,,,

,,,,,,,

,,,,,,,

dB

20

15

5

10

O

O

5

10

30

40

U

dB

20

15

5

10

O

O

5

10

30

40

U

,,,,,,,

,,,,,,,

, ,,,,,,

, ,,,,,,

,,,,,,,

,,,,,,,

,,,,,,,

, ,,,,,,

, ,,,,,,

,,,,,,,

LEFT RIGHT

CONTROL R M