Sound Performance Lab 2711 - Manual (Page 10)

10 RackPack: Preference Mic Pre
Mic Gain
With the Mic Gain control you can regulate the preamplification of the
microphone signal. It ranges from +14 dB to +72 dB. The input stage can
handle input levels of up to 18 dB. The value set with the Mic Gain con-
trol defines the output level equally for both Output 1 and Output 2.
When you set the Mic Gain you have to consider the type of micro-
phone that you are using (dynamic or condenser microphone) as well
as its sensitivity. The sensitivity of a dynamic microphone is at around
2 mV/Pa whereas the sensitivity of a condenser microphone can be up
to 20 mV/Pa. The result is a difference in output of 20 dB.
You should also consider the sound pressure level of the sound source,
the distance of the microphone to it and the acoustics of the room
when you set the preamplification.
About Leveling
Initially you should always ensure to have deactivated the -10 dB but-
ton so that the VU meter displays correct values (see “-10 dB” on page
11). Now turn up the Mic Gain control until the VU meter displays max-
imum levels between 0 dB and +3 dB. At this level you don’t risk any
overdrive when you experience sudden and unexpected peaks in the
level of the source. Always remember that the VU meter only shows
average values and that a peak level can be much higher (up to +10 dB).
If necessary, turn on the PPM mode to see the actual peak levels.
Usually levels of around 0 dB and +3 dB are safe. If, however, you expe-
rience very high peaks already at minimum Mic Gain values (i.e. drums,
brass instruments), you can activate the PAD function (see “PAD”
on page 12). The input level is now reduced so that you can regulate
Mic Gain again in a useful range.
If you know in advance that the level will be very consistent you can
always turn up Mic Gain. In this case you can activate the -10dB button
to have more headroom in the display.
IMPORTANT: To exclude any audible distortion the OVL LED should only
light up shortly. It starts illuminating 3 dB before a potential overload,
so first illumination does not indicate an overload, but that the limit of
leveling is reached. Avoid permanent illumination of the OVL LED to
exclude overloads (also refer to “Overload LED” on page 13).
Control Elements
Mic Gain, About Leveling






































 

 












































E#

.*$
("*/