Antares MDT user manual

							MDT UserÕs Manual41 Lesson 3: Multiband Applications
loudness of the other sounds. The following example demonstrates the use
of a multiband compressor to alleviate the pumping problem.
1. Select the ÒBass SoloÓ soundÞle for playback.
2. Choose Pumping 1 band in the Setting menu.
The compression ratio above the threshold is 10 to 1.
3. Start playback with looping.
Notice how the loudness of the cymbal and sustained pad is ÒpumpedÓ 
by the bass solo.
4. Choose Better 5 band in the Setting menu.
This setting is the same as before except for the use of multiband mode. 
Notice how the pumping effect is greatly reduced.
Extreme settings are used in the example so as to create pumping in the out-
put for the purposes of illustration. In a real world application, with a more
moderate compression ratio and release time, the multiband compressor
would provide even better results. 
						

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Managing Tonal Balance In Multiband Mode
What is the Tonal Balance Problem?
You may have noticed in the previous exercises that the multiband Peak
Level Indicators almost never have the same simultaneous level. This is
because the energy distribution across the spectrum changes from moment
to moment. Since all the bands are using the same I/O Curve, each band
may receive a different gain depending on its current level and placement
on the I/O Curve. The following example demonstrates this behavior.
1. Select the ÒShort VoiceÓ soundÞle for playback.
2. Choose 3:1, -48 dB threshold in the Setting menu.
3. Start playback with looping.
Listen for the tonal balance of the voice.
4. Choose 3 Band in the Filter Mode menu.
Notice how the tonal balance is brighter. The highs are accentuated 
because the average level of the High band is about 5 dB lower than the 
other bands. This means that it is getting less gain reduction than the 
other bands and is therefore ÒhotterÓ in relation to them. 
5. Stop playback.
-15 dB
-8 dB 
						

							MDT UserÕs Manual43 Lesson 3: Multiband Applications
How To Achieve Tonal Balance
It is often desirable to preserve the soundÞleÕs original tonal balance while
beneÞting from using multiband mode. The key element in preserving
tonal balance is having each band get the same amount of gain at the same
time. You can do this by offsetting the input level of the ÒhotterÓ bands to
equal the lowest level band. The following exercise demonstrates two dif-
ferent ways to achieve this.
1. Start playback with looping.
2. Press and hold the ÒFlatÓ button for about 2 seconds.
The Input Offset values for each band are automatically adjusted so that 
they have equal amounts of gain reduction over the period of time the 
Flat button is held down. That is, the Input Offset values are adjusted so 
that the bands receive, on the average, equal amounts of gain reduction 
as measured over the period the button is held down. This technique is 
applicable when the natural tonal coloration of the sound does not vary, 
as is the case with a single speaker Õs voice.
3. Choose Full Band in the Filter Mode menu.
Notice how the 1 band tonal balance closely matches the tonal balance of 
the adjusted 3 band sound.
4. Click on the ÒResetÓ button to zero the Input Offset values.
5. Click on the ÒVariableÓ button.
Offsetting the inputs
so that they are about
equal insures that all
the bands receive the
same gain. 
						

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44MDT UserÕs Manual
The Input Offset values now change continuously, in an ongoing effort 
to achieve equal amounts of gain reduction. The amount of gain reduc-
tion is measured over a period of time equal to three times the compres-
sor release time. In this way, the separate bands can respond 
individually to what is occurring in the sound, but at the same time, they 
are being drawn towards one-another to preserve the original tone color.
Using the ÒVariableÓ button will preserve the original tone color of 
sounds having variable tone color. The ÒFetesÓ and the ÒBass SoloÓ are 
good examples of this.
6. Stop playback.
IMPORTANT:
The ÒVariableÓ button requires CPU processing to work. MDT does this pro-
cessing when it is given control of the CPU to update meters. MDT is not
given the CPU when the plugin is not visible. Hence, the ÒVariableÓ button
will not work when the plugin is not visible. In order to achieve the effect of
the ÒVariableÓ button when the plugin is not visible, you must record the
resulting input offset level changes using automation in ProTools 4. 
						

							MDT UserÕs Manual45 Lesson 3: Multiband Applications
MDT As A Spectral Enhancer
The tonal ßexibility demonstrated above can be used to modify the existing
tonal balance dynamically. De-essers, spectral enhancers, and dynamic EQs
all modify the tonal balance dynamically. This example below shows how
to use MDT to perform these functions.
De-esser
1. Select the ÒShort VoiceÓ soundÞle for playback.
2. Choose 6:1 de-esser in the Setting menu.
The compression ratio above the threshold is 6 to 1. Notice how the I/O 
Curve straddles the diagonal. Sounds above the threshold and to the left 
of the diagonal get ampliÞed. Sounds to the right of the diagonal receive 
gain reduction.
3. Start playback with looping.
Notice how the High band is effected by compression and the other 
bands are offset so they get no compression. 
4. Use the Bypass button to compare the original with the compressed signal.  
						

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5. Press the High bands downward Input Offset Arrow until the display reads -14.
The High band peaks will occur at approximately the 0 dB gain line (the 
diagonal). This setting should sound very similar in tonal balance to the 
original. Any high frequency peaks will be compressed at a 6 to 1 ratio.
Spectral Enhancer
1. Press the High bands downward Input Offset Arrow until the display reads -20.
The High band peaks are now occurring in the area of the I/O Curve to 
the left of the diagonal. The sound is brighter because the highs are get-
ting ampliÞed while still being compressed at a 6 to 1 ratio. 
2. Experiment with changing the tonal balance by moving the other bands into the 
compression segment of the I/O Curve. 
3. Use the Bypass button to compare the original with the enhanced signal. 
4. Stop playback.
With the current setting of the I/O Curve, the louder a band gets, the more
gain reduction it receives. The next example shows how to conÞgure MDT
as a dynamic EQ. 
						

							MDT UserÕs Manual47 Lesson 3: Multiband Applications
Dynamic EQ
A dynamic EQ is a device that changes the amount of equalization it
applies as a function of input level or some other changing parameter of the
signal. MDT can be conÞgured as a dynamic EQ as shown below.
1. Select the ÒFetes 1Ó soundÞle for playback.
2. Choose High Freq. Expander in the Setting menu.
The expansion ratio above the threshold is 1 to 1.5.   
3. Start playback with looping.
Notice how the High and Hi Mid bands are effected by expansion and 
the other bands are offset so they get no expansion.   The louder the 
input signal, the greater the ampliÞcation of the highs. 
4. Use the Bypass button to compare the original with the enhanced signal. 
5. Experiment with changing the brightness of the sound by changing the offset of 
the High and Hi Mid bands.
The effect can range from subtle to gross depending on the ratio of the 
I/O Curve and the position of the band on the curve.
6. Stop playback.
1 to 1.5 expansion ratio 
						

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Lesson 4: Clip Sentry
This lesson will step you through how to use Clip Sentry.
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
reducing gain only when clipping is about it occur. 
1. Select the ÒShort VoiceÓ soundÞle for playback.
2. Choose ÒReset SettingsÓ from the settings menu.
3. Start playback with looping.
Notice how the gain reduction meter does not move. This is because the 
I/O Curve is along the diagonal line. Hence no gain reduction is pre-
scribed.
4. Increase the ÒGain (dB)Ó until the clipping begins to occur.
You can tell when clipping occurs because the clip light above the gain 
reduction meter ßashes red.
5. Click the ÒClip SentryÓ button in.
You will now see that gain reduction occurs when clipping used to 
occur. Also, notice that additional processing delay has been inserted 
into the signal path. 
6. Reduce the amount of delay to 5 mSec by changing the Clip Sentry Buf Len.
The Clip Sentry Buf Len causes less delay to occur for processing but it 
also causes the gain reduction to occur more quickly. Depending on the 
source material, shortening the delay will eventually cause objectionable 
distortion.
7. Gradually decrease the Clip Sentry Release time. 
						

							MDT UserÕs Manual49 Lesson 5: Using Automation
This causes the gain reduction to recover more quickly. Be careful, 
though. If the gain r
eduction recovers too quickly, data in the Clip Sentry 
buffer may cause superÞcial clipping to occur. A release time of 100 
rarely produces clipping. 
8. Stop playback.
If a large gain reduction occurs, a very short release will be less audible, but
may sound unnatural. 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.
With Clip Sentry, if youÕre doing Rock-n-Roll, you can push it to the wall. If
you have big Þnal gain, short Buf Len (mS) and short Release (mS), you can
make a REALLY loud piece. Just listen carefully for distortion: You will be
creating more distortion from the fast gain change of a short Buf Len (mS)
than the occasional slight clip from the short Release (mS). 
Lesson 5: Using Automation
ProTools version 4.0 introduces Automation for plugin controls.
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 ÒVari-
ableÓ, ÒFlatÓ and ÒResetÓ buttons by using them when the input offset lev-
els automation is recorded.
The MDT Settings menu is also automated. Care must be taken, however,
not to automate ÒSave Setting As...Ó or ÒDelete Setting...Ó because these dia-
logs 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.
This lesson steps you through how to use automate the effects of the ÒVari-
ableÓ button (a very important tool for preserving tone color). 
						

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50MDT UserÕs Manual
1. Select the ÒShort VoiceÓ soundÞle for playback.
2. Choose 3:1, -48 dB threshold in the Setting menu.
3. Select Ò5 BandÓ from the Filter Mode menu.
4. Enable the Input Offset arrows for automation.
In ProTools 4, click the ÒautomationÓ button in the plugin window and 
ÒAddÓ the controls ÒLevel4Ó, ÒLevel3Ó, ÒLevel2Ó, ÒLevel1Ó and 
ÒLevel0Ó. After clicking the ÒOKÓ button, the Input Offset Arrows will 
be hilited Green. Next change the trackÕs Òauto readÓ to Òauto touchÓ.
5. Click the ÒVariableÓ button in.
6. Start playback with NO
 looping.
Playback will end after ÒShort VoiceÓ plays through.
7. Click the ÒVariableÓ button out and change Òauto touchÓ to Òauto readÓ.
8. Start playback.
You will see that the Input Offset Arrow changes were recorded and that 
playback automation resulted from the ÒVariableÓ button having been 
pushed during recording.
9. Stop playback.