Cedar DNS3000 User manual

The CEDAR DNS3000
Dialogue noise suppressor
Version 1.0
18 April 2008
Copyright CEDAR Audio Ltd, © 2008
CEDAR is a registered trademark of CEDAR Audio Ltd
E&OE, Subject to revision at the Company’s sole discretion
interstage
Phistersvej 31, 2900 Hellerup, Danmark
Telefon [phone], fax [phone]
www.interstage.dk
-pro audio with a smile

CEDAR DNS3000 dialogue noise suppressor

Table Of Contents
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Table Of Contents
Introducing the CEDAR DNS3000..................................................................................... 1
Safety Instructions ........................................................................................................ 3
Getting Started ............................................................................................................. 4
Connections.................................................................................................................. 5
Front Panel Indicators and Controls .................................................................................. 6
Stand-alone operation.................................................................................................... 8
Case studies and tutorials ............................................................................................. 10
Case 1: Suppressing traffic noise ................................................................................ 10
Case 2: Suppressing tape hiss .................................................................................... 12
Case 3. Suppressing excessive reverberation ................................................................ 13
Advanced use ............................................................................................................. 14
System pages .......................................................................................................... 15
Using Scenes ........................................................................................................... 18
Remote Control ........................................................................................................... 23
Installing the DNS Software .......................................................................................... 24
Using the RCS............................................................................................................. 26
RCS Tutorial ............................................................................................................... 28
Contact Information..................................................................................................... 31
Technical Support........................................................................................................ 32
Firmware maintenance .................................................................................................33
Specifications and CE Certificates................................................................................... 35
Licence and Limited Warranty........................................................................................ 37

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CEDAR DNS3000 dialogue noise suppressor
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Introducing the CEDAR DNS3000
In 2000, CEDAR Audio launched the DNS1000 dialogue noise suppressor. This was a stand-
alone, desktop-format unit designed specifically for film production, dubbing, outside broadcast
(remote) and studio noise suppression. It was ideal for replacing analogue units that had been
in use for many years, and for use in situations where rapid setup and processing was required
‘on the fly’. Two years later, we released the DNS2000, a rackmount version of the DNS
technology designed specifically for use with Pro Tools, both on the Mac and PC.
Today, the DNS3000 offers the manual control of the DNS1000 and its successor, the DNS1500,
the Pro Tools integration of the DNS2000, plus an internal system of scenes, memories, and
(when slaved to timecode) snapshot automation with moving faders.
Quality, speed and simplicity are paramount considerations in the DNS range, and all three
models offer the following:
■Near zero latency
A group delay of less than 10 samples (typically less than 1/200th of a frame) so there is no
loss of lip-sync when using DNS.
■Flexibility
DNS will handle a wide range of noise suppression requirements.
■Speed and ease of use
Each DNS offers a carefully designed user-interface that maximises speed of use.
■Audio interfaces
24-bit digital audio interfaces conforming to AES/EBU and SPDIF standards.
■Universal power supply
A DNS will work anywhere in the world.
■Powerful processors
40-bit floating-point DSP processors ensure that each model will handle the most complex
processing requirements.

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CEDAR DNS3000 dialogue noise suppressor
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Safety Instructions
Read these instructions and follow them.
■Water and moisture
The DNS3000 must not be exposed to rain or moisture. Furthermore, if the unit is brought
directly from a cold environment into a warm one, moisture may condense inside it. This, in
itself, will not cause damage, but may cause electrical shorting. This could damage the unit, and
even cause danger to life. ALWAYS allow a unit to reach ambient temperatures naturally before
connecting the mains power.
■Mounting and ventilation
The DNS3000 should be placed on a placed on a flat, stable surface. Do not subject it to strong
sunlight, excessive dust, mechanical vibration or periodic shocks. It is not susceptible to heat
build-up, but should be installed away from heat sources such as radiators, and audio devices
such as amplifiers that produce large amounts of heat.
■Power sources
The DNS3000 features a universal power supply that will work safely on any mains supply in the
ranges 85V to 260V, 50Hz or 60Hz AC only. The unit should always be grounded (or ‘earthed’),
and power connectors should be routed so that they will not be walked on or pinched.
If the unit is not to be used for an extended period, unplug it from the wall. Pull the connector
out by the plug, never by the cord itself.
■Connections
Turn off the power to all equipment before making any connections.
■Cleaning
Clean the DNS3000 only with a dry cloth. Never use abrasive pads or liquid cleaners such as
alcohol or benzene.
■Damage requiring service
The DNS3000 contains no user-serviceable parts and should on no account be opened or
dismantled by unauthorised personnel. It should be returned to qualified service agents when it
has been exposed to liquids, when it fails to function correctly, when it has been dropped, or
when the case is damaged.

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Getting Started
Unpacking
Unpack the DNS3000 carefully. Save the carton and all packing materials since you may need
them to transport the unit in the future. In addition to the unit and the packaging, the carton
should contain the following:
■mains connection lead
■software CD-ROM including this manual
■warranty registration card
Installation site
To maintain reliability and prolong operating life, observe the following environmental
considerations:
■the nominal temperature should be maintained between 5° and 35° Celsius
■relative humidity should be in the range 30% to 80% non-condensing
■strong magnetic fields should not exist nearby.
Mains power inlet and switch
Mains power is provided using the standard IEC power cord supplied with the DNS3000.
Mains power is switched on and off using the switch on the rear panel. However, you may
normally leave this switched on and use the power switch on the top panel to turn the DNS3000
on and off.

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Connections
Audio
The DNS3000 offers two audio connection standards. It passes its signal to both outputs
irrespective of the input used. The standards are:
Digital SPDIF format
You should connect the SPDIF output from your source to the SPDIF input of the DNS3000 using
a single cable terminated with an RCA (or 'phono') plug. The SPDIF output of the DNS3000
should be connected to the SPDIF input of a recording device or external DAC.
Digital AES/EBU format
The AES/EBU format is used by professional digital audio devices. You should connect the
AES/EBU output from your source to the AES/EBU input of the DNS3000 using a single cable
terminated with an XLR plug. The AES/EBU output of the DNS3000 should be connected to the
AES/EBU input of a recording device or external DAC.
Locking
The DNS3000 will automatically detect which input to use and will lock to any sample rate
presented up to 96kHz. If the sample rate is not one of the standard sample rates, the filter
table for the nearest standard will be used and scaled accordingly. The Bypass button will flash
slowly to indicate an I/O error such as no lock.
There is no indication of which input has been selected. To avoid confusion, the unit should be
used with only one input connected.
Ethernet
The Ethernet connection allows the DNS3000 to communicate with a remote system. Connect it
to a suitable network using a standard Ethernet cable. See the System Pages for detailed
network setup instructions.
LTC In
The DNS3000 recognises LTC timecode.

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Front Panel Indicators and Controls
Power
■Power on/off button
Press this to switch the DNS3000 on, and hold it to switch the unit off.
If you switch off using the rear panel switch without first powering down using the soft power
button, you risk corrupting the internal memory of the unit.
Channel Selection
■Channel Selectors
The channel selection buttons select which processing channel(s) is/are connected to the
process controls.
■When the CHAN1 button is lit, the process controls affect the processing on channel 1.
■When the CHAN2 button is lit, the process controls affect the processing on channel 2.
■You can apply the same settings to both channels by pressing CHAN1 and CHAN2
together (or in quick succession).
Process Controls
■Process Off button
Switch processing on and off.

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■Range Selectors
The Range Selectors concentrate the unit’s activity into the desired part of the audio spectrum.
■Level control
The Level control tells the DNS3000 how much noise is present in the input signal.
■Band Gain controls
The Band Gain controls determine the maximum amount of processing that the DNS3000 will
apply in each band.
■Activity LEDs
These offer a visual indication of the activity in each of the bands. When a green LED is lit, the
signal is being attenuated in that band; when a red LED is lit, the signal is being boosted.
Screen & Softkeys
In addition to the Power on/off button, there are nine small buttons in the upper section of the
panel. In general, those that are active at any given moment are illuminated, while those that
are inactive are extinguished.
■Soft buttons
Use to select menu items as displayed on the screen.
■Close button []
Takes you back to the previous screen (if there is one) and saves changes if applicable.
■Previous and Next buttons [ and ]
Move between objects that may require selecting, scrolling or editing.
■Spinwheel
Use to scroll through lists, edit characters and alter parameter values.
Hardware Bypass
■Bypass
Passes the audio directly from the input to the output without processing.
This control affects both channels regardless of the status of the channel selection buttons.

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Stand-alone operation
The DNS process divides a signal into a large number of well defined bands. Sophisticated digital
filters analyse each of these bands and suppress the noise independently in each. The
innovative design of this filter bank allows you to control the unit using relatively few front panel
controls.
Channel Selectors
Your first job will be to select the channel that you wish to set up. You can select CHAN1 or
CHAN2 individually, or link them by pressing both buttons in quick succession, whereupon the
settings of the channel selected first are copied to that selected second. (You unlink the
channels by pressing just one of the buttons.)
Range Selectors
Next, you should identify the frequency range or ranges in which the noise lies. You can press
each of the Range Selector buttons individually, or combine them to choose any one of six
possible processing ranges:
Low
20Hz - 400Hz
Mid
200Hz - 6kHz
High
4kHz - 18kHz
Low + Mid
20Hz - 6kHz
Mid + High
200Hz - 18kHz
Full Range
20Hz - 18kHz
To select Low + Mid or Mid + High, press the appropriate two buttons simultaneously or in quick
succession. To select Full Range, press the Low and High buttons simultaneously or in quick
succession.
Selecting a range concentrates all of the filters within the DNS3000’s filter bank across that part
of the audio spectrum.
Level control
Your next job will be to identify the noise level of the audio.
With the appropriate channel(s) and range(s) selected, pull all six Band Gain controls and the
Level control down fully. Now increase the Level slowly. At first, you will hear very little happen
but, at some point determined by the noise content of the recording, you will hear the noise
disappear. You should attempt to find the point at which this occurs.
Placing the Band Gain controls in their lowest position ensures that maximum processing will
occur as you increase the Level control, thus making identification of the noise easier.

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Band Gain controls
Once you have chosen the range(s) and determined the Level, you control the action of the
DNS3000’s filter bank using the Band Gain controls.
The six faders represent six frequency bands distributed from lower frequencies (left) to higher
frequencies (right) across the selected range.
You will use the Band Gain controls to control the amount of noise attenuation performed in
each band, adjusting them to suppress as much noise as possible without introducing unwanted
artefacts into the desired signal.
Noise suppression occurs in a given band when the fader is below the 0dB line. However, there
are occasions when you might wish to boost the signal in a given band, and you can do this by
moving the appropriate fader above the 0dB line.
Activity LEDs
The twelve Activity LEDs offer a visual indication of the activity in each of the six bands
controlled by the Band Gain controls.
■Both LEDs off: Less than ±0.5dB activity
■Green LED lit: The signal is being attenuated
■Red LED lit: The signal is being boosted
The brightness of an LED offers an indication of the amount of attenuation or boost applied.
Each band controls numerous filters. Therefore, the Activity LEDs in a given band display the
overall activity in that band, and are not necessarily indicative of the action of any single filter at
that moment.
Bypass
You can route the input directly to the output by pressing the Bypass button. This allows you to
switch off all processing, regardless of any other settings, either on the DNS3000 itself
(including the in-built scenes and automation) or obtained by remote control. The signal latency
is not affected by the Bypass state.
This control affects both channels regardless of the status of the channel selection buttons.
The Bypass button flashes slowly to indicate an I/O error such as no lock.

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Case studies and tutorials
The following case studies describe just three of the ways in which you can use the DNS3000.
You can apply the DNS3000 equally to recorded signals and to ‘live’ signals at the point of
recording or transmission.
Case 1: Suppressing traffic noise
The DNS3000 can suppress background noises such as road traffic, aircraft, air conditioning,
wind, rain, and many other common soundstage, location, and OB (remote) problems that
contaminate audio. If your signal exhibits any of these, you can suppress them as follows.
First, identify the frequency range(s) in which the noise lies.
You should be able to do this by listening to the problem. However, if this proves difficult, you
can use the following method. It is not important that you find the perfect settings at the first
attempt. In particular, you will be able to refine your Level and Band Gain settings once you
have found the correct range.
Begin as follows:
Select the correct channel(s)
Ensure that the DNS3000 is not in Bypass
Select Full Range
Set all six Band Gain controls to -24dB
Raise the Level control until the noise disappears
At this point you have determined an approximate setting for the Level. This is necessary for
determining the Range but it is likely that you will refine this later in the procedure.
When the Level is close to the ideal setting, you should see the Activity LEDs flicker in response
to the signal content.
Now continue as follows:
Raise the Band Gain controls to 0dB (no processing occurs)
Adjust the Band Gain controls to suppress the noise
You should always attempt to suppress the noise with the minimum of damage to the desired
signal.
In all likelihood, you will find that the leftmost Band Gain controls are pulled down significantly,
whereas the central and rightmost are close to 0dB. This tells you that the problem does not lie
in the upper frequencies, so you should use the Range Selector to select Low+Mid. Then repeat
the steps marked ‘’.
If you now find that you are using all six faders in similar fashion, it is likely that the noise is
distributed across the entire Low+Mid range. However, if the suppression is still heavily biased
towards the left hand faders, you should now select the Low range alone and repeat the
procedure.

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If you select Low alone and cannot suppress the noise, it is probable that there is considerable
noise energy in the Mid band, so you should return to using Low+Mid ranges.
For many problems such as traffic noise, the noise will lie primarily in the range 50Hz - 1.5kHz.
In this case, Low+Mid will be the correct choice.
Second, optimise the Level control.
Listening carefully to the audio, refine the Level setting so that the noise is correctly identified
without introducing audible artefacts. If this proves difficult, you can return the Band Gain
controls to -24dB for this stage.
The DNS3000 takes a short period to ‘settle’ after moving the Level control (especially in the
lower ranges) so you should not adjust it rapidly.
Third, refine the Band Gain controls for optimum suppression.
Set all six Band Gain controls to 0dB. Now increase and decrease the gain in each band
separately while listening to the effect that each has on the noise. This will identify the bands
that contain the majority of the noise. (Do not be alarmed if all six bands contain significant
noise. This is not unusual.)
Let’s assume that the greatest improvement occurs when you reduce the gain in bands 3 and 4.
This suggests that the noise is concentrated in an approximate range of 200Hz to 1kHz. You
should now find the optimum positions for all six faders. The greatest cuts will lie in bands 3 and
4, whereas bands 1, 2, 5 and 6 should remain as close to 0dB as possible to ensure that
minimal signal damage occurs in the bands that do not contain much noise.
The final configuration may look like this:

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Case 2: Suppressing tape hiss
The DNS3000 can suppress the tape hiss that mars many older recordings. It will also improve
the signal/noise ratio of dialogue tapes that have been poorly copied as well as those that are
many generations old.
First, identify the frequency range(s) in which the noise lies.
You should follow the procedure laid down in case 1 to determine the range(s) in which the
problem lies. For most instances of tape hiss, you will find that the Mid+High ranges are most
appropriate. In a few cases you may find that the High range alone is most suitable. It is not as
common to require suppression in the Low range because hiss is usually less prominent at lower
frequencies, and it may also be masked by the genuine audio in the range.
Second, optimise the Level control.
To determine the correct Level, you should again follow the procedure described in case 1.
Third, refine the Band Gain controls for optimum suppression.
As in case 1, you should start with all six Band Gain controls at 0dB. You should then increase
and decrease each control individually to find the bands that contribute most hiss to the signal.
Because tape hiss often exhibits a ‘white’ profile at Mid and High frequencies, you may find that
satisfactory results are achieved with the Band Gain controls set in a horizontal line.
However, hiss is generally less annoying at very high audio frequencies. Consequently, you may
be able to reduce the amount of processing in the uppermost bands. This will help to ensure
that any low amplitude signal components lying at high frequencies (which provide much of the
‘air’, ‘ambience’ or ‘life’ in a signal) are passed with little or no attenuation.
The final configuration may look like this:

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Case 3. Suppressing excessive reverberation
In many situations, the DNS3000 can suppress excessive reverberation. This can be useful in TV
production when you need to match the audio from a large recording studio or soundstage to
visual images set in a small room or other enclosed space. Suppressing reverberation can also
be beneficial in increasing the intelligibility of poor dialogue recordings.
The method used to suppress reverberation is as follows:
First, set the range in which the reverberation lies.
In general, reverberant spaces include soft materials that absorb high frequencies more rapidly
than middle and lower frequencies. Even bare rooms with hard walls include these materials:
they are the actors. Consequently, you will find that Low+Mid is almost always the most
appropriate combination of ranges for suppressing reverberation.
Second, set the Band Gain controls.
You should set all six Band Gain controls to -24dB. This will ensure that (provided the other
controls are set correctly) the DNS3000 processes the ‘tails’ of the sound without adversely
affecting the desired signal.
Third, optimise the Level control.
Starting at its minimum position (-80dB) increase the Level control slowly. At some point before
full noise suppression becomes apparent, you will hear the tails of louder sounds become
truncated. You can adjust the amount of truncation of the reverb using the Level control rather
than the Band Gain controls.
The final configuration may look like this:

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Advanced use
The following section of the manual describes how to set up the DNS3000 and how to use its
advanced features, including its presets, snapshots and timecode facilities.
Front Page
The front page shows the process settings for both channels, allowing you to see the complete
setup without flipping between the channels using the CHAN1 and CHAN2 buttons.
The soft keys perform the following actions:
■Preset: opens the preset manager page.
■Snpsht: opens the snapshot manager page.
■T.Gain: toggles the ‘touch’ state of the gain control for the selected channel.
■T.Lvl: toggles the ‘touch’ state of the level controls for the selected channel.
■System: opens the system setup page.
When a parameter is ‘touched’ it ignores any settings that may be sent from a remote
controller.
Remote Control
The legend ‘RMT’ appears in the top left corner of either channel when a remote controller is
controlling that channel.

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System pages
System Setup Page
This page reports the firmware version and provides access to the various system setup pages.
Fader Calibration Page
Fader calibration is necessary only after a firmware upgrade or after a faulty fader is replaced.
The procedure is as follows:
■Move all the faders to the bottom of their travel and press ‘-24dB’.
■Move all the faders to the top of their travel and press ‘+6dB’.
■Move all the Gain faders to 0dB, and the Level fader to -20dB (i.e. in line with the others)
and press ‘0dB’.
■The Close button should now be lit. Press this to save the calibration and to close the page.

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Panel Brightness Page
This allows you to adjust the brightness of the various panel elements and the screen.
Use the Next and Prev buttons to step through the list, and the spinwheel to adjust the values.
Pressing Close saves the settings.
TCP/IP Setup page
The network interface may be configured automatically if your network has a DHCP server, or
manually. Toggle between these states by pressing EDIT when the Config menu item is
indicated.
Auto (DHCP)
If automatic, the rest of the page shows the current settings for information only.
Manual
If manual, you may edit the network settings by scrolling to the wanted menu item and pressing
Edit. You may then use the Prev and Next buttons and the spinwheel to edit values in the usual
fashion.
Settings are saved when you close the page.
Switching DHCP on or off takes effect at the next system boot. Other changes in settings take
effect when you close this page.
You may need to consult your network administrator for help in connecting the DNS3000 to your
network. If required, the unit MAC address is printed on the rear of the unit. When connected
and configured correctly, the DNS3000 responds to ‘ping’ packets.