Antares MDT user manual

							MDT UserÕs Manual51 Lesson 5: Using Automation
New Possibilities
You have probably thought of numerous applications for MDT that have
not been mentioned in the Tutorial. We hope that you have learned enough
about whatÕs possible with MDT that you feel free to experiment and create
ways to use it that are far beyond anything we expected.
Here is something to play with as a starting point that could produce
unique results in a sound design application.
Inverted Gain Curves
In the region effected by the inversion, increasing input level decreases the
output. Try out the Inverse Pluck setting with the ÒpluckÓ soundÞle. 
						

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CHAPTER 4MDT Reference
This chapter explains the detailed operation of every aspect of MDTÕs user
interface. The items are organized in alphabetical order to make them easy
to locate. 
Attack Slider
The Attack slider controls the amount of time it takes for MDT to react to an
incoming peak. The range of the control is from 0 milliseconds to 50 milli-
seconds. The current attack time is displayed in the window to the left of
the slider. 
Clicking on the arrows decrements/increments the attack time by one milli-
second. Pressing on the arrows decrements/increments the attack time con-
tinuously. Press  to slow the speed at which the value increments.
The thumb wheel can be dragged for making gross adjustments.
Automation
All buttons and sliders (except for the ÒVariableÓ, ÒFlatÓ and ÒResetÓ but-
tons) have been automated when used with ProTools 4.0. Note that the
ÒVariableÓ, ÒFlatÓ and ÒResetÓ buttons control the input offset levels, which
are automated. Hence, you can automate the effects of the ÒVariableÓ, ÒFlatÓ
and ÒResetÓ buttons by using them when the input offset levels automation
is recorded. 
						

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The Settings menu is also automated. Care must be taken, however, not to
automate ÒSave Setting As...Ó or ÒDelete Setting...Ó because these dialogs
will be posted when automation plays back. Moving points in the I/O
Graph cannot be automated, although changing sets of points can be
recalled with the Settings Menu automation.
Bypass Button
Clicking on the Bypass button bypasses the settings of MDT. This is useful
for comparing the original soundÞle to the processed version being pre-
viewed. Clicking again will revert to the current settings.
Clip Sentry Button
Because MDT simulates the smooth sound of analog compressors, it is easy
to create data that exceeds to +1,-1 digital range. This is because of the
behavior of the Attack Time slider, which allows you to control the rate of
gain reduction due to a sudden increase in sound level. As in the analog
world, even a fast attack time will let through a faster transient. Since most
users jack-up the output gain to compensate for compression, these fast
transients almost always result in clipped data.
Clip Sentry is a high speed digital limiter designed to prevent clipping by a
reducing gain only when clipping is about it occur. 
The indicator light to the right of the Clip Sentry button shows when the
Clip Sentry is being activated. 
						

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Clip Sentry Buf Len (mS) slider
A very short length will introduce distortion by making rapid gain reduc-
tions. This distortion will be minimal if Clip Sentry does not reduce the gain
too often or too much. A long length will introduce more delay in the pro-
cessed data and even produce audible drop-outs before transients on some
sounds.
Clip Sentry Release (mS) slider
If a large gain reduction occurs, a very short release will be less audible, but
may sound unnatural. A short release also increases the chance that the gain
will recover too quickly, causing a mild clipping of audio data that is
already in the buffer. A release time of 100 rarely produces clipping. A
longer release time will be more audible. The Release (mS) slider controls
how rapidly the gain is allowed to change. Hence, you have the Release
Slider set to 1000 and rapidly increase the Gain Slider, you will Þnd the
actual output gain shows by the gain reduction meter will increase slowly.
Clipping Indicator
With MDÕs soft clipping, it is difÞcult to hear when clipping occurs. To Þx
this, use the Clip Indicator above the Gain Reduction meter. The Clip Indi-
cator is initially black. It brießy turns yellow whenever MDT output hits 
						

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+1,-1 values. After the yellow subsides, it latches to red. You may reset it to
black by clicking on it.
Control Surface Support
TDM pagetables have been implemented allowing MDT to be controlled by
external control surfaces, including the JL Cooper CS-10, Peavey PC 1600,
Digidesign ProControl and Mackie HUI.
Delay Window
The Delay Window shows the amount of time in seconds that MDT will
delay a trackÕs sound output. This delay is introduced due to MDTÕs Òlook
aheadÓ peak detection feature and processing delay. The amount of the
delay introduced gets larger with the number of bands used. Tracks can be
slipped to the left by the amount shown in the Delay Window to resynchro-
nize their output with other non-processed tracks.
Filter Mode Menu
MDT uses digital Þlters to separate the energy of the input signal into mul-
tiple bands. The Filter Mode Menu contains the following choices:
¥Full Band: No Þlters are used. The sound is processed in one band. The
frequency response of this mode is 0 Hz to the Nyquist, ±0.0 dB with no
passband ripple.
¥3 Band: The signal is divided into 3 equal bands, 3 octaves in width. The
frequency response of this mode is 0 Hz to the Nyquist, ±0.0 dB with
±0.7 dB passband ripple.  
						

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¥5 Band: The signal is divided into 5 equal bands, 2 octaves in width. The
frequency response of this mode is 0 Hz to the Nyquist, ±0.0 dB with
±0.3 dB passband ripple.
¥3 Band AP: The signal is divided into 3 equal bands with a special Þlter
design optimized for the ßattest pass band near unity gain. The fre-
quency response of this mode is 0 Hz to the Nyquist, ±0.0 dB with ±0.0 to
0.7 dB passband ripple.
¥5 Band AP: The signal is divided into 5 equal bands with a special Þlter
design optimized for the ßattest pass band near unity gain. The fre-
quency response of this mode is 0 Hz to the Nyquist, ±0.0 dB with ±0.0 to
0.3 dB passband ripple.
The AP (all pass) versions of the multiband Þlters are optimized for mini-
mum coloration at gains around 0 dB. Because of hardware limitations, the
AP mode Þlters have a limited gain reduction range of -12 dB. This means
that the input signal cant be attenuated more than 12 dB without having its
tonal balance seriously altered. In cases where more gain reduction is
needed, the normal non-AP version of the Þlter will give the best result. 
Placing the I/O Curve in
the shaded parts of the Grid will
cause unpredictable
changes in the tonal
balance when using AP
mode Þlters. 
						

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Flat Button
Pressing the Flat Button equalizes the apparent input level of the bands dis-
played in multiband modes. MDT adjusts the offset of each band to equal
the apparent level of the quietest band. As long as you hold down the ÒFlatÓ
button, the spectral band levels are averaged, and input offset level adjust-
ments are continuously updated. Consequently, the average coloration over
the period the ÒFlatÓ button is held down will be neutral.
Gain Slider
The Gain slider adjusts the loudness of the signal after processing. The
range of the control is from -24 dB to +24 dB. The current gain is displayed
in the window to the left of the slider. 
Clicking on the arrows decrements/increments the gain by one deciBel.
Pressing on the arrows decrements/increments the gain continuously. Press
 to slow the speed at which the value increments. The thumb
wheel can be dragged for making gross adjustments.
Input Offset Arrows
The Input Offset Arrows allow you to change the relationship of the input
signal to the I/O Curve without actually changing the signal level of the
input data. The placement of thresholds can be tweaked in this way. In
multiband conÞgurations, spectral bands can be independently adjusted.
By adjusting the different bands to the same input level, coloration is
reduced. Adjusting the different bands to completely separate sections of
the I/O Curve allows independent compression ratios and levels for each
band. The range of adjustment is from 0 dB to -96 dB.
The Input Offset Arrows normally increment in 2 dB steps. Press 
then click or press on the arrows to increment is 1 dB steps. 
						

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In/Out Display
The In/Out Display shows the position of the cursor when it is located
inside the In/Out Grid. The units displayed are in dB below full scale. The
In/Out Display shows the location of thresholds and terminators when
they are being dragged.
When dragging a threshold, the In/Out Display also shows the compres-
sion or expansion ratios of the curve segments on either side of the thresh-
old. Ratios expressed as N to 1 are compression ratios. Ratios expressed as 1
to N are expansion ratios. Ratios expressed as 1 to -N or -N to 1 are inverse
gain curves which donÕt have equivalents in the analog world.
In/Out Grid
The In/Out Grid is the primary interface for controlling MDT.
Input Offset Arrows
Input Offset Display 
						

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All the possible points where the I/O Curve can exist are represented by the
In/Out Grid. It is divided by a diagonal line that represents the points on
the Grid that have input levels equal to output levels (e.g. -48:-48). Placing
the I/O Curve on this diagonal will cause MDT to output the signal at the
same level as it was input. 
The points on the Grid which have output levels lower than their input lev-
els (e.g. -48:-72) are located below the diagonal. Placing the I/O Curve
below the diagonal will cause MDT to output the signal at a lower level
than it was input.
Points on the Grid which have output levels higher than their input levels
(e.g. -72:-48) are located above the diagonal. Placing the I/O Curve above
the diagonal will cause MDT to output the signal at a higher level than it
was input.
Click, or click-drag to position new points on the I/O Grid. To delete a
point, place the cursor over the point (a special cursor is activated) and
option-click the point. 
To move a point, place the cursor over the point (a special cursor is acti-
vated) and click-drag it. The new setting takes effect while the mouse is
moving (you hear the drag as you move the point). On slower machines,
you may want to press and hold down  while changing the I/O
Curve. This will cause MDT change the curve setting only after the point
drag is complete.
-48:-48
-48:-72 -72:-48