ALESIS M1 Active Mk2 User Manual
Page 27
Speaker Installation
M1 Active Mk2 Reference Manual
29
T
O SET THE LEVEL WITH A MIXER
:
1. Turn on all system components (the M1 Active Mk2s last) and turn the M1
Active Mk2’s INPUT LEVEL control all the way down.
2. Play program through the mixer and raise the mixer’s fader levels until its
meter averages around “0 VU”.
3. Raise the Control Room Output to its nominal position (usually “2
o’clock” or 3/4 of the way up).
4. On one speaker, raise its INPUT LEVEL CONTROL for a comfortable
level in the engineer’s seat (if you have a sound pressure meter, 85 dB SPL
is a common standard for listening).
5. Match the level for the other speaker. Note that the numbers on the back
panel are only a rough guide; for precise left/right imaging, use pink
noise or test tones and a sound pressure meter.
The Input Level control has a 28 dB range with a center detent. The detent has
no particular meaning, but helps in adding a mental “reference position”
when attempting to set levels from in front of the speaker. With the control at
a maximum clockwise rotation, 2.0 volt input will produce full amplifier
output (102 dB SPL “A” weighted from two speakers at 1 meter).
For the technically-minded, here is an approximate chart of SPL levels for
various settings of the INPUT LEVEL control, measured at 1 meter from two
speakers simultaneously (all settings, especially near the extremes of the
range, are subject to a plus or minus 2 dB error):
Mark
-10 dBV
nominal
+4 dBu
nominal
0 (MIN)
-- dB SPL
-- dB SPL
1
--
--
2
57.0
69.0
3
63.5
75.5
4
68.2
80.2
5
71.0
83.0
6
73.0
85.0*
7
78.0
90.0
8
83.5
95.5
9
85.5*
97.5
10 (MAX)
86.5
98.5
* denotes recommended setting for control room use