miniDSP DDRC-88D User manual

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DDRC-88D
8-CHANNEL AUDIO PROCESSOR
WITH DIRAC LIVE®TECHNOLOGY
AND OPTIONAL UPGRADE FOR BASS MANAGEMENT AND CROSSOVER
Digital I/O version
User Manual

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Revision history
Revision
Description
Date
0.1
First draft
31 July 2017
1.0
Public release
4 Sept 2017

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TABLE OF CONTENTS
Important Information...................................................................................................................................5
1Product Overview ....................................................................................................................................7
1.1 Typical system configurations ....................................................................................................................................7
1.2 How Dirac Live® works ...............................................................................................................................................8
1.3 Configuration steps (basic mode) ..............................................................................................................................9
1.4 Configuration steps (enhanced/bass management mode)......................................................................................10
2Hardware Connectivity...........................................................................................................................11
2.1 Digital input and output ...........................................................................................................................................11
2.2 DC Power..................................................................................................................................................................12
2.3 USB ...........................................................................................................................................................................12
3Software Installation..............................................................................................................................13
3.1 Dirac Live license activation .....................................................................................................................................13
3.2 Installation ― Windows ...........................................................................................................................................14
3.2.1 Possible Windows installation issues ..............................................................................................................14
3.2.2 DDRC-88BM plugin installation .......................................................................................................................14
3.2.3 Dirac Live Calibration Tool (DLCT) installation.................................................................................................14
3.3 Installation ― Mac ...................................................................................................................................................15
3.3.1 Possible Mac installation issues.......................................................................................................................15
3.3.2 DDRC-88BM plugin installation .......................................................................................................................15
3.3.3 Dirac Live Calibration Tool (DLCT) installation.................................................................................................15
4The DDRC-88BM Plugin ..........................................................................................................................16
4.1 Plugin user interface –basic mode ..........................................................................................................................16
4.2 Synchronizing with the DDRC-88D ...........................................................................................................................17
4.3 Master control..........................................................................................................................................................17
4.4 Configuration/filter set selection .............................................................................................................................17
4.5 Dirac Live information ..............................................................................................................................................18
5Acoustic Measurement for Dirac Live......................................................................................................19
5.1 Loudspeaker and microphone positioning...............................................................................................................19
5.2 Preparing for acoustic measurement.......................................................................................................................20
5.2.1 Connections and microphone placement .......................................................................................................20
5.2.2 Subwoofer settings..........................................................................................................................................20
5.3 Configuring for measurement..................................................................................................................................21
5.3.1 Select the configuration/preset (enhanced/bass management mode) ..........................................................22
5.3.2 Sound System tab ............................................................................................................................................22
5.3.3 Mic Config tab..................................................................................................................................................23
5.3.4 Output & Levels tab.........................................................................................................................................24
5.3.5 Custom System configuration .........................................................................................................................25
5.4 Running the measurements .....................................................................................................................................26
5.4.1 Listening environment.....................................................................................................................................27
5.4.2 Executing measurements ................................................................................................................................28
5.4.3 Completing the measurements .......................................................................................................................29
5.4.4 Viewing and redoing measurements...............................................................................................................29
5.5 Saving and loading projects......................................................................................................................................29
6Dirac Live Filter Design ...........................................................................................................................30

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6.1 Working with graphs ................................................................................................................................................31
6.2 Designing your target curve .....................................................................................................................................33
6.2.1 The Auto Target ...............................................................................................................................................33
6.2.2 Editing the target curve ...................................................................................................................................33
6.2.3 Guidelines for target curve design ..................................................................................................................34
6.2.4 Saving and loading target curves.....................................................................................................................35
6.3 Generating correction filters....................................................................................................................................36
6.4 Loading filter sets .....................................................................................................................................................37
7Using the DDRC-88D Audio Processor .....................................................................................................38
7.1 Configuring source equipment.................................................................................................................................38
7.2 Front panel ...............................................................................................................................................................38
7.2.1 Status indicators ..............................................................................................................................................38
7.2.2 Front panel controls ........................................................................................................................................38
7.3 Infrared remote control ...........................................................................................................................................39
8Enhanced/Bass Management Mode .......................................................................................................40
8.1 Plugin user interface –enhanced/bass management mode....................................................................................40
8.2 Signal flow ................................................................................................................................................................41
8.3 Plugin design/configuration guide ...........................................................................................................................42
8.4 Connecting and configurations ................................................................................................................................43
8.4.1 Connection options .........................................................................................................................................43
8.4.2 More about configurations..............................................................................................................................44
8.4.3 Selecting a configuration .................................................................................................................................44
8.4.4 Saving and loading configurations...................................................................................................................44
8.4.5 Relationship with Dirac Live ............................................................................................................................45
8.4.6 Restoring to defaults .......................................................................................................................................45
8.5 Signal processing tabs ..............................................................................................................................................46
8.6 LFE Mgt.....................................................................................................................................................................46
8.7 Routing .....................................................................................................................................................................48
8.8 Mixer ........................................................................................................................................................................49
8.9 Outputs.....................................................................................................................................................................50
8.9.1 Channel label ...................................................................................................................................................50
8.9.2 Gain control and level monitoring...................................................................................................................50
8.9.3 Parametric EQ..................................................................................................................................................51
8.9.4 Crossover settings ...........................................................................................................................................53
8.9.5 Time delay .......................................................................................................................................................54
8.9.6 Invert and mute...............................................................................................................................................54
9Additional Information...........................................................................................................................55
9.1 Specifications ...........................................................................................................................................................55
9.2 MCU Firmware update.............................................................................................................................................56
9.2.1 Windows..........................................................................................................................................................56
9.2.2 Mac OS X..........................................................................................................................................................58
9.3 Activating enhanced/bass management mode........................................................................................................60
9.4 Troubleshooting .......................................................................................................................................................61
9.5 Obtaining support ....................................................................................................................................................62

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IMPORTANT INFORMATION
Please read the following information before use. In case of any questions, please contact miniDSP via the
support portal at minidsp.desk.com.
SYSTEM REQUIREMENTS
To configure your DDRC-88D audio processor, you will require a Windows or Apple Mac computer with the
following minimum specification:
Windows
•Intel Pentium III or later, AMD Athlon XP or later
•2 Gigabytes (GB) of RAM or higher
•Keyboard and mouse or compatible pointing device
•Microsoft• ® Windows® Vista® SP1/Win7/Win8/Win10
•Two free USB 2.0 ports
Mac OS X
•Intel-based Mac with 1 GHz or higher processor clock speed
•2 Gigabytes (GB) of RAM or higher
•Keyboard and mouse or compatible pointing device
•OS X 10.9 (Mavericks) to macOS 10.12 (Sierra)
•Two free USB 2.0 ports
DISCLAIMER/WARNING
miniDSP cannot be held responsible for any damage that may result from the improper use or incorrect
configuration of this product. Please read this manual carefully to ensure that you fully understand how to
operate and use this product, as incorrect use or use beyond the parameters and ways recommended in this
manual have the potential to cause damage to your audio system.
Please also note that many of the questions we receive at the technical support department are already
answered in this User Manual and in the online application notes on the miniDSP.com website. So please take
the time to carefully read this user manual and the online technical documentation. And if an issue arises with
your unit, please read through the Troubleshooting section first. Thank you for your understanding!
WARRANTY TERMS
miniDSP Ltd warrants this product to be free from defects in materials and workmanship for a period of one
year from the invoice date. Our warranty does not cover failure of the product due to incorrect connection or
installation, improper or undocumented use, unauthorized servicing, modification or alteration of the unit in any
way, or any usage outside of that recommended in this manual. If in doubt, contact miniDSP prior to use.

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FCC CLASS BSTATEMENT
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
•This device may not cause harmful interference.
•This device must accept any interference received, including interference that may cause undesired
operation.
Warning: This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection. This
equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance
with the instructions, may cause interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful interference to radio
or television reception, which can be determined by turning the equipment off and on, the user is encouraged to
try to correct the interference by one or more of the following measures:
•Reorient or relocate the receiving antenna.
•Increase the separation between the equipment and receiver.
•Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
•Consult the dealer or an experienced radio/TV technician for help.
Notice: Shielded interface cable must be used in order to comply with emission limits.
Notice: Changes or modification not expressly approved by the party responsible for compliance could void the
user’s authority to operate the equipment.
CE MARK STATEMENT
The DDRC-88D has passed the test performed according to European Standard EN 55022 Class B.
ANOTE ON THIS MANUAL
This User Manual is designed for reading in both print and on the computer. If printing the manual, please print
double-sided. The embedded page size is 8 ½” x 11”. Printing on A4 paper will result in a slightly reduced size.
For reading on the computer, we have included hyperlinked cross-references throughout the manual. In
addition, a table of contents is embedded in the PDF file. Displaying this table of contents will make navigation
easier.

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1PRODUCT OVERVIEW
Thank you for purchasing a miniDSP DDRC-88D audio processor powered by Dirac Live®, the world’s premier
room correction solution. We are delighted to offer you this software and hardware combination, the fruit of
extensive research and development and years of experience in sound system tuning.
The DDRC-88D is an 8-channel digital audio signal processor (DSP) running the Dirac Live® room correction
algorithm. The onboard floating-point SHARC processor provides time and frequency correction of 8 channels
with optional bass management and active crossover configurations. Inputs and outputs are digital (AES/EBU x
4), provided on a DB-25 connector. All output channels are sample-rate-converted to the same rate as the input
(channels 1 and 2) to preserve system sample rate integrity.
The DDRC-88D is a member of the miniDSP Dirac Series of audio processors. Deploying a DDRC-88D will:
•Improve imaging and immersion
•Improve clarity of music and dialog
•Reduce listening fatigue
•Remove resonances and room modes
1.1 TYPICAL SYSTEM CONFIGURATIONS
In studio or sound reinforcement applications, the DDRC-88D is typically connected between a mixing console
and a multichannel DAC, as shown below. Each channel can be set for either full-range or subwoofer operation,
and active multi-way systems can also be implemented.
The DDRC-88D can also be used for multi-room/multi-zone correction with a stereo source. See the application
note on our website, Multi-zone DRC with the DDRC-88D Dirac Live® processor.

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Computer connectivity is used to perform acoustic measurements and generate digital room correction filters.
Up to four sets of correction filters can be stored on the DDRC-88D processor and recalled from the front panel
or via an infrared remote. Once the processor is fully configured, the computer is no longer needed.
1.2 HOW DIRAC LIVE®WORKS
The miniDSP DDRC-88D audio processor includes Dirac Live®, a premium mixed-phase room correction
technology. This technology is used not only in home stereo and home theater systems but also in cinemas,
recording studios, and luxury cars.
As with any room correction system, Dirac Live® corrects the system’s magnitude response (often referred to
imprecisely as “frequency response”). In contrast to fully automated systems, Dirac Live® corrects the
magnitude response towards a user-adjustable target response. The target response takes account of the
natural frequency range of the loudspeaker system and the normal effects of loudspeaker dispersion on the
measured in-room magnitude response.
In addition, Dirac Live® corrects the system’s impulse response, which reflects how the system responds to a
sharp transient such as a drumbeat. Reflections, diffraction, resonances, misaligned drivers, and so on, all
combine to smear out the transient. An ideal loudspeaker has none of these, so correcting the impulse response
makes the speaker in the room behave much more like that ideal loudspeaker. The impulse response is a critical
factor for accurate sound-staging, clarity and bass reproduction. Dirac Live® employs a sophisticated analysis
algorithm to make the optimal correction across the whole listening area, not just at a single point.
Dirac Live® accomplishes this using mixed-phase filters –filters that match a desired magnitude response and
generate a customized impulse response. This contrasts with the minimum-phase and linear-phase filters that
are commonly used in audio applications. While minimum-phase and linear-phase filters are relatively easy to
design, they are tightly constrained in their impulse response characteristics –neither can make a desired
change to the magnitude response independently of controlling the impulse response. In some cases, they may
even make things worse.
Mixed-phase filters are more difficult to design, but the audible performance of Dirac Live® is due to its success
in using mixed-phase filters to make the system response across the whole listening area more closely resemble
that of an ideal speaker. The energy from the direct wave and from early reflections is optimally combined to
arrive as a single wave front to the listener. Late reflections are left largely untouched, being corrected only for
their spectral coloration, as they contribute to a larger, more enveloping soundstage.
Illustration of Dirac Live® magnitude and impulse response correction

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1.3 CONFIGURATION STEPS (BASIC MODE)
The steps for configuring the DDRC-88D audio processor with Dirac Live® are summarized as follows:
1. Connect the DDRC-88D audio processor into your system and install
software. See Section 2, Hardware Connectivity and Section 3,
Software Installation.
2. Run a series of acoustic measurements using the Dirac Live
Calibration Tool for miniDSP program, to capture the acoustic
behavior of your speakers and room. See Section 5, Acoustic
Measurement for Dirac Live.
3. Generate digital room correction filters that will be executed by the
DDRC-88D processor. Up to four filter sets can be downloaded into
the processor for easy real-time recall and auditioning. See Section
6, Dirac Live Filter Design.
4. Once the digital room correction filters are designed and
downloaded, the computer can be disconnected for normal
listening. See Section 7, Using the DDRC-88D Audio Processor.

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1.4 CONFIGURATION STEPS (ENHANCED/BASS MANAGEMENT MODE)
The steps for configuring the DDRC-88D audio processor with Dirac Live® and the optional enhanced/bass
management mode upgrade are summarized as follows:
1. Connect the DDRC-88D audio processor into your system and install
software. See Section 2, Hardware Connectivity and Section 3,
Software Installation.
2. Configure output channel processing with the DDRC-88BM plugin.
This sets up individual control of each output channel in order to
implement (for example) active crossovers or multisub
management. See Section 8, Enhanced/Bass Management Mode.
3. Run a series of acoustic measurements using the Dirac Live
Calibration Tool for miniDSP program, to capture the acoustic
behavior of your speakers and room. See Section 5, Acoustic
Measurement for Dirac Live.
4. Generate digital room correction filters that will be executed by the
DDRC-88D processor. Up to four filter sets can be downloaded into
the processor for easy real-time recall and auditioning. See Section
6, Dirac Live Filter Design.
5. Configure bass management in the DDRC-88BM plugin (if
required). See Section 8, Enhanced/Bass Management Mode.
6. The computer can be disconnected for normal listening. See Section 7, Using the DDRC-88D Audio
Processor.

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2HARDWARE CONNECTIVITY
All connections to the DDRC-88D are made on the rear panel.
2.1 DIGITAL INPUT AND OUTPUT
Up to eight channels can be connected to the DDRC-88D via the supplied DB-25 breakout cable. 4 AES/EBU
digital inputs and four AES/EBU digital outputs are present on the connector using the TASCAM pinout.
The supplied cable has the following channel assignment:
Channels
Color
In 1&2
Purple
In 3&4
Blue
In 5&6
Green
In 7&8
Orange
Out 1&2
Yellow
Out 3&4
Red
Out 5&6
Grey
Out 7&8
Brown
Input sample rate
All inputs have asynchronous sample rate conversion (ASRC) and accept sample rates from 32 to
192 kHz. Each pair of channels can have a difference sample rate.
Output sample rate
All outputs run at the sample rate of input channels 1 and 2. If there is no signal on input
channels 1 and 2, all output channels run at 48 kHz.
Note that the internal sample rate is 48 kHz regardless. An asynchronous sample rate conversion on the output
channels is used to produce data at the sample rate detected on input channels 1 and 2, thus preserving the
sample rate integrity of the system as a whole.

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2.2 DC POWER
The supplied 5 VDC power supply includes a set of interchangeable power pins. Fit the correct pins for your
country. Connect the DC plug to the 5 VDC power socket.
Apply power to the DDRC-88D only after all input and output connections have been made. The DDRC-
88D uses little power and can be left powered on all the time.
2.3 USB
To configure the DDRC-88D using Dirac Live Calibration Tool for miniDSP:
•Connect the USB port of the DDRC-88D to a USB 2.0 port on your computer using the supplied cable.
•Connect a miniDSP UMIK-1 to a second USB port on your computer.
Note: the miniDSP UMIK-1 is the only measurement microphone that can be used with the DDRC-88D and Dirac
Live Calibration Tool for miniDSP. Other USB microphones or microphones connected to external soundcards
cannot be used.

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3SOFTWARE INSTALLATION
If you purchased your product directly from miniDSP, your software will be available from the User Downloads
section of the miniDSP website when your order ships. You will need to be logged into the website with the
account you created when purchasing to access the download.
If you purchased your product from a miniDSP dealer, you will receive a coupon together with the product.
Redeem this coupon and select the Plugin Group “Dirac Series” at the link below:
•https://www.minidsp.com/support/redeem-coupon
The User Downloads link is visible from the dropdown menu at the top right of the website page:
Navigate to the Dirac Series section and then to DDRC-88BM Software. There you will find a single download
containing all software. Download this file and unzip it on your computer (on Windows, right-click and select
“Extract All...”; on Mac, double-click). The folder containing the software has a name like DDRC-88-BM_v1_4
and will contain the following folders:
Dirac Live
This folder contains the installers for Dirac Live Calibration Tool for miniDSP (DLCT)
multichannel version, which is used to perform the Dirac Live calibration, including taking
measurements, generating correction filters, and loading them into the DDRC-88D. There are
separate Windows and Mac versions.
Plugins
This folder contains the installers for the DDRC-88BM plugin, used to set up non-Dirac signal
processing, configure remote control codes and perform various other maintenance operations
on the DDRC-88D. There are separate Windows and Mac versions.
firmware
This folder contains the firmware for the DDRC-88D. miniDSP may occasionally provide updated
firmware to improve functionality and performance –see Section 9.2 MCU Firmware update for
the upgrade procedure.
3.1 DIRAC LIVE LICENSE ACTIVATION
As of version 1.2.0 of Dirac Live Calibration Tool, license activation is done automatically when DLCT recognizes a
valid Dirac Live license code in the hardware unit itself. No separate manual activation step is required.

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3.2 INSTALLATION ―WINDOWS
3.2.1 Possible Windows installation issues
The miniDSP software requires that a number of other frameworks be installed for it to work. For Windows 7
and later, these packages should be installed automatically. For earlier versions of Windows, please download
and install the following frameworks before attempting to install any miniDSP software. You can also manually
install these if you receive an error message that required software is missing.
•Microsoft .NET framework (version 3.5 or later)
•Latest version of Adobe Air
•Microsoft Visual C++ 2010 Redistributable Package: for x86 (32-bit operating system) or x64 (64-bit operating
system).
3.2.2 DDRC-88BM plugin installation
1. Navigate to the Plugins folder of the software download and then to the Windows folder.
2. Double-click on the DDRC_88_BM_v1_4.exe installer program to run it (the version number v1_4 may be
different). We recommend that you accept the default installation settings.
3.2.3 Dirac Live Calibration Tool (DLCT) installation
1. Navigate to the Dirac Live folder of the software download and then to the Windows folder.
2. Double-click on the installer to run it. The installer will have a name similar to Dirac Live Calibration Tool (8
channels) v1.2.0.8354 Setup.exe (the version number starting with v1.2... may be different). We
recommend that you accept the default installation settings.
The first time you run DLCT, you may see a warning from Windows Firewall as shown below. If so, ensure that
“Private networks...” is checked and “Public networks...” is not checked. Then click on “Allow access.”

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3.3 INSTALLATION ―MAC
3.3.1 Possible Mac installation issues
If double-clicking on an installer brings up a message that the installer cannot run, use this alternate method:
1. Right-click on the installer (or click while holding the Control key).
2. On the menu that pops up, move the mouse over the “Open With” item and then click on “Installer
(default).”
3. The following window will appear. Click on “Open.”
3.3.2 DDRC-88BM plugin installation
1. Navigate to the Plugins folder of the software download and then to the Mac folder.
2. The installer program is named DDRC_88_BM_v1_4.pkg (the version number v1_4 may be different). To
run it, double-click on it, or right-click and open as described above. We recommend that you accept the
default installation settings.
3. To run the DDRC-88BM plugin, locate DDRC-88-BM.app in the Applications -> miniDSP folder and double-
click on it. To make it easier to run in future, right-click on its dock icon and select Options -> Keep in Dock.
3.3.3 Dirac Live Calibration Tool (DLCT) installation
1. Navigate to the Dirac Live folder of the software download and then to the Mac folder.
2. The installer program will have a name similar to Dirac Live Calibration Tool (8 channels) v1.2.0.8392.mpkg
(the version number starting with v1.2... may be different). To run it, double-click on it, or right-click and
open as described above. We recommend that you accept the default installation settings.
3. To run DLCT, locate Dirac Live Calibration Tool.app in the Applications -> miniDSP -> nanoAVR folder and
double-click on it. To make it easier to run in future, right-click on its dock icon and select Options -> Keep
in Dock.

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4THE DDRC-88BM PLUGIN
The DDRC-88BM plugin is the software program that interfaces with the DDRC-88D for all control functions
except for Dirac Live calibration. It can operate in two modes:
•Basic mode. Dirac Live is enabled but the optional bass management and crossover functionality is not.
•Enhanced/bass management mode. Dirac Live is enabled as well as bass management and crossover
functionality. See Section 8, Enhanced/Bass Management Mode for further information on this functionality.
If you purchased a DDRC-88D in basic mode and later upgrade to enhanced/bass management mode, you will
need to perform the upgrade procedure described on page 60.
Be sure to quit Dirac Live Calibration Tool for miniDSP before starting the DDRC-88BM plugin.
Running both programs at the same time may result in communication conflicts and odd behavior.
4.1 PLUGIN USER INTERFACE –BASIC MODE
Upon starting the plugin, the main user interface appears. The screenshot below shows the user interface with
the key areas highlighted.
At the top of the screen are a set of menus and buttons, which are described on following pages. Below that, on
the Dirac tab, is a display of the Dirac Live parameters. This tab is active in both basic and enhanced/bass
management modes.
The four other tabs (“LFE Mgt,” “Routing,” etc.) are not active in basic mode. They can be viewed when the
plugin is offline (see next page) in order to provide you with a preview of the enhanced/bass management
functionality.

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4.2 SYNCHRONIZING WITH THE DDRC-88D
Connect the DDRC-88D to a USB 2.0 port on your computer. Then click on the Connect button:
If you are running the plugin in enhanced/bass management mode, a dialog box with additional connection
options may appear. See page 43.
If successful, the button will change to a green tick as shown above. For the sake of brevity, this state is referred
to as “online” whereas the earlier state with the circular arrows is referred to as “offline.” In addition, the
Master Volume field will display the current volume setting:
4.3 MASTER CONTROL
These controls are only effective when the plugin is online.
The Mute button disables all audio output:
The Dirac Live button turns Dirac Live filtering on and off. (A Dirac Live correction filter must have been loaded
into the currently selected configuration for this to work.)
4.4 CONFIGURATION/FILTER SET SELECTION
Once correction filters have been loaded into the DDRC-88D, the four configuration selection buttons can be
used to select between them.
If the plugin is operating in enhanced/bass management mode, these buttons also select the processing data for
the four other tabs (“LFE Mgt,” “Routing,” etc.). Because these different configurations contain data that has
already been loaded into the flash memory of the hardware unit, they are also often referred to as “presets.”
Configuration/preset selection can also be done with the front panel encoder or an infrared remote control –
see Section 7, Using the DDRC-88D Audio Processor.
By default, configuration 1 is selected:

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4.5 DIRAC LIVE INFORMATION
In basic mode, the only active tab in the interface is Dirac. Note that Dirac Live calibration is performed with the
separate program Dirac Live Calibration Tool for miniDSP (DLCT), as described in Sections 5 and 6. Once
calibration has been performed, you can quit DLCT and run the plugin to view Dirac Live delay and gain settings
and real-time levels.
In the DDRC-88BM plugin, this tab displays the gains and delays of the Dirac Live filters loaded into the DDRC-
88D. (The plugin must be online to display them.) These gains and delays were calculated by DLCT during its
Optimize phase and cannot be changed by the user –they are “read only.” Here is an example:
Note that the displayed gains and delays are applied even when Dirac Live filtering is turned off.
The Input and Output columns display the current signal level at the inputs and outputs of the Dirac Live
processing block.
The button is used to turn Dirac Live processing on and off.

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5ACOUSTIC MEASUREMENT FOR DIRAC LIVE
The Dirac Live Calibration Tool For miniDSP uses a set of measurements made in your listening room to gather
all the acoustical information about your room and speakers that it needs to calculate the correction filters.
If you have purchased the enhanced/bass management mode upgrade and intend to configure individual output
channels with crossovers or filters, you must do that before running a Dirac Live Calibration. See Section 8,
Enhanced/Bass Management Mode.
5.1 LOUDSPEAKER AND MICROPHONE POSITIONING
Prior to performing acoustic measurements, loudspeaker and subwoofer positioning should be optimized. In
particular, the location of the subwoofer will have a large impact on bass response. With Dirac Live®, you have
more freedom with loudspeaker and subwoofer placement, but the best result will still be achieved if optimal
placement is used together with Dirac Live®.
Typical home theater measurement setup
A total of nine measurements are needed, with the microphone located in different positions in the room and
pointed vertically (that is, at the floor or ceiling). The first measurement must be taken at the central location of
the listening area, as this location sets the levels and delays of each speaker. While this location will usually be
an equal distance from both speakers, Dirac Live® will adjust in cases where it is not. Eight more measurements
are then taken at locations spread around the listening area and at different heights from the floor.

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5.2 PREPARING FOR ACOUSTIC MEASUREMENT
5.2.1 Connections and microphone placement
The figure below shows a typical connection diagram for performing acoustic measurement. No changes to the
audio connections are needed. Simply:
•Connect the supplied USB (type A to type B) cable from the DDRC-88D to a USB port on the computer.
•Connect a USB cable (type A to mini type B) from the UMIK-1 to a USB port on the computer.
Place the UMIK-1 microphone into a microphone stand and position the computer and cabling so that there is
enough freedom of movement to move the microphone into the needed locations. A small tripod stand is
supplied with the UMIK-1, but a larger stand with boom arm can be used if desired. If necessary a longer USB
cable can be used (up to a total USB cable length of 5 meters). In larger spaces, an active USB repeater may be
needed. We recommend that the microphone be oriented vertically (pointed at the floor or ceiling) and the “90
degree” calibration file used (see Mic Config tab on page 23).
5.2.2 Subwoofer settings
We recommend that during calibration the low pass filter of the subwoofer be disabled if possible, or set to its
highest frequency if it cannot be disabled. Any EQ on the subwoofer should be disabled or set “flat.” High pass
filters used to protect the driver from over-excursion should be left in place.
If the subwoofer’s low pass filter is an important part of the overall bass management in the system, it can be
re-enabled after completing Dirac Live calibration and loading correction filters into the DDRC-88D.