Antares MDT user manual

							MDT UserÕs Manual31 Lesson 2: Single Band Applications
The Gain slider is set at 18 dB to compensate for the gain reduction of the 
compressor. The loudest sounds will come out at approximately the 
same level as before compression.
Notice how the quiet string passage is now louder than before. The brass 
remains at its previous level. 
6. Use the Bypass button to compare the original with the compressed signal. Deac-
tivate Bypass when youÕre done.
7. Change the compression ratio to 4 to 1 by dragging the upper terminator down 
until the Left Ratio Þeld in the I/O Display equals 4:1.
The compression ratio approaches ¥ to 1 as the I/O Curve approaches 
the horizontal. At a ratio of ¥ to 1, all sounds above the threshold would 
be output at the same level.
8. Stop playback.
Attack and Release Times
The time it takes for MDT to react to an incoming peak is controlled by the
Attack Time. The Release Time determines how fast the input level will
return to its quiescent state after the peak comes through. The following
section is a demonstration of the effect that Attack and Release times have
on the sound. 
-16 dB gain-24 dB gain 
						

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MDT should now be adjusted to a 4 to 1 compression ratio from the last sec-
tion. If it isnÕt, please do this now.
1. Select the ÒpluckÓ soundÞle for playback.
2. Reduce the Gain setting to 14. 
3. Start playback with looping.
4. Use the Bypass button to compare the original with the compressed signal. Deac-
tivate Bypass when youÕre done.
The region, ÒPluckÓ, is a loud violin section pizzicato with a reverb tail. 
Notice how the compression exaggerates the reverb and the noise in the 
sample. Notice the ÒshapeÓ of the reverb tail and its decay time. Also 
notice the body of the attack portion of the sample.
5. Reduce the Attack time to 0 mS. 
The initial attack is now compressed. MDT reacts immediately to change 
the gain so that the attack is output at a much lower level.
6. Press on the right arrow of the Attack slider. Notice the change in the body of the 
sound as the Attack time increases.
At 50 mS, the attack is much louder than the sustained portion of the 
ÒPluckÓ. Changing the Attack time lets you tailor the aggressiveness of 
the attack to your needs.
7. Return the Attack setting to 20 mS. 
4 1
A four unit change in
the input gives a one
unit change on the
output. 
						

							MDT UserÕs Manual33 Lesson 2: Single Band Applications
8. Increase the Release setting to about 5,000 mS. 
Notice how the reverb tail sounds almost exactly like the uncompressed 
version. This is because the Release time is much longer than the reverb 
time. The shape of the reverb tail is not effected because the detected 
input level (as shown by the Peak Level Indicator) decays very slowly 
when the Release time is this long. 
This slow release time has an additional effect. Since the peak input level 
is high, the gain reduction of the output signal is also high, causing it to 
play back more softly than before. The Gain slider can be adjusted to 
compensate for this effect.
9. Decrease the Release time to about 300 mS. 
At this setting, the rate of change in output gain is approximately equal 
to the reverb decay rate. The result sounds like a smooth decay with the 
reverb compressed. 
10. Stop playback. 
						

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34MDT UserÕs Manual
Expander/Gate
MDT can be used as an expander/gate to eliminate noise and for creating
gated effects. This section demonstrates how to use the I/O Curve to con-
Þgure a downward expanding gate.
1. Choose 1:1, -36 dB gate from the Settings menu.
1. Start playback with looping.
As the reverb decays below the -36 dB threshold, the output gain 
changes to -60 dB, gating the sound off. 
2. Press  and then the downward Input Offset Arrow until the display 
reads -15.
The reverb tail is now gated off sooner because the input level reaches 
the -36 dB threshold sooner. The Input Offset Adjust Arrows can be used 
in conjunction with the Release time slider to get exactly the gate time 
you wish. 
						

							MDT UserÕs Manual35 Lesson 2: Single Band Applications
3. Move the lower terminator to the left until the value displayed in the I/O Display 
equals 1:2.0.
The reverb now decays evenly because the output gain tapers gradually 
below the -36 dB threshold.
4. Stop playback.
Example 2: Compressor with Noise Gate
1. Select the ÒShort VoiceÓ soundÞle for playback.
2. Choose 3:1, -48 dB threshold from MDTÕs Settings menu.
3. Start playback with looping.
Notice that the region has a high noise ßoor. The noise level is just below 
the -48 dB threshold.
4. Drag the lower terminator to the right as far as it will go.
You will hear that the noise is gated out for the most part. There is still a 
small noise just after the words ÒÉSound Designer IIÉ(noise)Ó.
5. Decrease the Gain setting to 9 dB. 
6. Press  and then the downward Input Offset Arrow until the display 
reads -15.
1 to 2.0 expansion ratio 
						

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The noise is virtually eliminated because the input signal has been 
shifted down in relationship to the gating threshold. The noise now 
gates off immediately.
7. Stop playback.
ÒTubeÓ Compander
Many complex signals like full mixes and vocals require a high degree of
dynamic control, but suffer from the effects of heavy compression or limit-
ing. The use of a Òsoft kneeÓ compressor or Òtube-likeÓ compander can
make the effects of strong compression less obvious. A Òsoft kneeÓ com-
pressor is characterized by having a gradual change in compression ratio at
its threshold. A ÒtubeÓ compander has a continuously varying compression
ratio over the range of the input.
Example 1: ÒSoft KneeÓ comp/gate
1. Choose Òsoft kneeÓ 4:1 -36 dB from the Settings menu.
2. Start playback with looping.
Compare this sound with the previous example. The voice sounds less 
ÒsquashedÓ even though the compression ratio is higher because the 
change in ratio at the threshold is less abrupt.
3. Stop playback. 
						

							MDT UserÕs Manual37 Lesson 2: Single Band Applications
Example 2: ÒtubeÓ comp/gate
1. Choose ÒtubeÓ comp/gate from the Settings menu.
2. Start playback with looping.
Contrast the sound of the voice with the previous two settings. The 
vocal sound is even more natural because, most of the time, it is sitting 
on an area of the I/O Curve which has relatively small compres-
sion/expansion ratios. Only the peaks or valleys of the signal are 
effected by the high ratio segments of the I/O Curve.
The reason ÒtubeÓ companders work so well for complex signals is 
because the compression/expansion ratio changes gradually from some 
central operating point Ð in this case, -36 dB, making the effects of com-
pression less audible. Normal compressors maintain the same ratio over 
a wide dynamic range.
3. Stop playback. 
						

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Example 3: Full mix
1. Select the ÒFetes 1Ó soundÞle for playback.
2. Select the Fetes 1 tube from the settings menu.
3. Start playback with looping.
The ratios of the downward expander part of the curve have been 
relaxed in this setting to accommodate the lower level and dynamic 
range of this excerpt. Compare the sound of this setting with the sound 
of the 3:1, -48 threshold setting that you used above.
4. Use the Bypass button to compare the original with the compressed signal. Deac-
tivate Bypass when youÕre done.
5. Stop playback. 
						

							MDT UserÕs Manual39 Lesson 3: Multiband Applications
Lesson 3: Multiband Applications 
In this lesson, you will learn how to use MDT in multiband mode. This
capability of MDT makes it the most powerful and ßexible dynamics pro-
cessing tool available.
Multiband Peak Level Indicators
In multiband mode, MDT divides the energy of the signal into three or Þve
equally spaced bands. The peak level of each band is displayed by its own
Peak Level Indicator at the bottom of the In/Out Grid.
1. Select the ÒShort VoiceÓ soundÞle for playback.
2. Select 3 band from the Filter Mode menu.
3. Start playback with looping.
The Peak Level Indicators display the level of each band. The three 
bands (High, Mid, Low) are shown in that order, the Low band being at 
the bottom of the In/Out Grid. Each band is 3.3 octaves wide and has its 
own Input Offset Arrows.
4. Select 5 band from the Filter Mode menu.
In 5 band mode, Þve Peak Level Indicators are shown - High, Hi-Mid, 
Mid, Low-Mid, and Low. Each band is 2 octaves wide.
High Band
High Mid Band
Mid Band
Low Mid Band
Low Band 
						

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The Filter Modes
MDT uses digital Þlters to separate the energy of the input signal into mul-
tiple bands. These Þlters have particular characteristics which need to be
understood to use MDT most effectively.
In the 3 Band mode and 5 Band mode, with the I/O curve along the diago-
nal line, MDT responds like an equalizer with gain levels set ßat. This
means there are +/- 1dB variations in amplitude as a function of frequency.
3 Band AP and 5 Band AP works differently, so that the output is identically
equal to the input, and the Þlters only become involved when the gain
curve is not on the diagonal.
Why not use the AP mode all the time? 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. In cases where more gain reduction is needed,
the non-AP versions will give the best result. 
Multiband Compressor
There are many times when it is necessary to compress a complete mix.
Often, especially when compressing at a high ratio, ÒpumpingÓ can occur.
This is when one sound or group of sounds in the mix is modulating the
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.