Sound Performance Lab Area 5.1 manual SPL Mic Array Operation, High precision gain preamplifiers

Area 5.1

SPL Mic Array

Operation

Preamplifier

6

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 0mV 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).