Sound Performance Lab Area 5.1 - Manual (Page 6)

6
Operation
Preamplifier
SPL Mic Array
The SPL Mic Array was designed to arrange any suitable micro-
phones in the setup based on the ASM 5 design of SPL’s Atmos 5.1
system. The outstanding quality of its 5.1 surround reproduction
has been proven in many occasions. With large double
membrane microphones in use, excellent tonal results are
combined with minimum efforts. Basic advantages of the combi-
nation with the SPL Mic Array are:
• First proven standard setup to capture three-dimensional sound
images in all recording situations
• Only one mic stand to mount the array
• Easy to move / fast and easy positioning
• Suited for all microphone types (matched mics recommended)
• First discrete 5.1 system for motion recordings
To get the most out of the Area 5.1 system it is essential to use
appropriate microphones. Most important for best results is to
use matched microphones at least for the L/R and SR/SL channel
pairs, however we recommend to employ five matched micro-
phones with large double membranes.
To start, choose cardioid microphone characteristics for all
five microphones. The microphones should point in the direc-
tions shown in the graphic to the left. Many variations of this
setup, depending on the microphones and recording situa-
tions, can be tested to find the best solution.
High precision gain preamplifiers
The Area 5.1 is equipped with five matched high precision micro-
phone preamps to capture the sound sources in the most trans-
parent, noiseless and uncolored way. The mic gain controls cover
a range from 24 dB up to 60 dB. Lundahl microphone transfor-
mers optionally available.
The microphone preamps employ SPLs unique ServoDrive-
Technology® which detects voltage differences (DC-offset)
between the positive and negative paths of the amplifying
stages. Any offset increases noise and distortion which compro-
mizes signal quality. ServoDrive minimizes DC-offsets to values
between 0 mV and 2 mV. The signal contains less noise and distor-
tion and improved tonal transparency.
Motorized master/slave mic gain controls
An important feature of the Area 5.1 are its motorized mic gain
controls. A switch enables motorized control over all five micro-
phone preamplifiers by just turning one control. This is important
when readjustment of the preamplification becomes necessary
while recording. Readjusting the preamplification manually is
impossible since only 2 channels can be adjusted at once. The
motorized mic gain controls also ensure not to influence the
coherence of the room sound (phasing effects occur already at
minimum differences).
Area 5.1