Software Instruction Manual

IQ–MSD Turbo 1.4 Advanced IQ System Software
Page 148
Auto Level: The Auto Level function is turned on and off with this control.
DAOL: The DAOL control sets the Desired Average Output Level for the Auto Level function. If the DAOL is set
to –20 dB, and the output signal level is –20 dB, nothing changes. The signal passes at the same level. But if the
signal is above –20 dB, the Auto Level function will reduce the gain to bring the level down to –20 dB. And if the
signal is below –20 dB, the gain is increased to increase the level up to –20 dB.
IMPORTANT: The Max Gain control is
not intended to be adjusted in “real time” while the ASA control is turned
on. Instead, use the DAOL control of the Auto Level function. The new level will not take affect until the Reaction
Time setting of the Auto Level function has transpired.
Reaction Time: The Auto Level function continually adjusts the signal level toward the DAOL value. But it
doesn’t adjust the signal in one jump. Instead, the Reaction Time control sets the size of each step. For example,
if the audio input signal stays at a constant level below the DAOL value, the gain would increase it to the DAOL
level over the time (in seconds) specified by the Reaction Time control. In the “real world,” audio signals
continually change, and so does Auto Level’s step size. This approach produces a very natural sounding auto
level control.
A Reaction Time of 4 seconds is a good starting point for speech. Try 6–10 seconds for music. Although a 4
second Reaction Time might seem slow, remember that the Auto Level function compensates for average
differences in level—such as between soft-spoken and boisterous speakers. If a sound source occasionally
“blasts,” you might also use the Input Compressor/Limiter function to control the transients.
Tip: The Auto Level function never raises the gain higher than Max Gain. As you set the value of Max Gain
higher, the Auto Level function will have more room to adjust the incoming signal. For inputs with an unusually
wide dynamic range, set Max Gain as high as possible so the Auto Level algo can bring up the quietest passages.
Tip: Use a long Reaction Time when the system is used to mute background music during a page. This
provides a pleasing and smooth transition back to background music after the page has been completed.
Fig. 6.12 The Third SMX-6 Sub-block Screen