miniDSP Flex User manual

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miniDSP Flex
2-IN 4-OUT HIGH-DEFINITION AUDIO PROCESSOR
WITH OPTIONAL DIRAC LIVE®ROOM CORRECTION TECHNOLOGY
User Manual

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Revision history
Revision
Description
Date
0.7
Preliminary for public acccess
2 December 2021

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TABLE OF CONTENTS
Table of contents...........................................................................................................................................3
IMPORTANT INFORMATION...........................................................................................................................6
1Product Overview ....................................................................................................................................9
1.1 Dirac Live upgrade................................................................................................................................... 10
1.2 Typical applications ................................................................................................................................. 10
2Software installation..............................................................................................................................12
2.1 Download the miniDSP software............................................................................................................. 12
2.2 Windows.................................................................................................................................................. 13
2.2.1 Possible Windows installation issues .............................................................................................. 13
2.2.2 Install the miniDSP-2x4-HD plugin................................................................................................... 13
2.2.3 Install the UAC2 driver..................................................................................................................... 13
2.3 Mac.......................................................................................................................................................... 14
2.3.1 Possible Mac installation issues....................................................................................................... 14
2.3.2 Install the plugin.............................................................................................................................. 14
3Hardware Overview...............................................................................................................................15
3.1 Rear panel................................................................................................................................................ 15
3.1.1 miniDSP Flex .................................................................................................................................... 15
3.1.2 Flex/Balanced .................................................................................................................................. 16
3.1.3 Flex/Digital....................................................................................................................................... 17
3.2 Front panel .............................................................................................................................................. 18
4Playing Audio.........................................................................................................................................19
4.1 Digital sources ......................................................................................................................................... 19
4.2 Analog source.......................................................................................................................................... 19
4.3 Bluetooth................................................................................................................................................. 20
4.4 USB Audio................................................................................................................................................ 22
4.4.1 macOS.............................................................................................................................................. 22
4.4.2 Windows.......................................................................................................................................... 24
5Remote control......................................................................................................................................26
5.1 Using the miniDSP remote ...................................................................................................................... 26
5.2 Learning third-party remote codes ......................................................................................................... 27
5.3 Android/iOS control app.......................................................................................................................... 28

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6The miniDSP-2x4-HD and DDRC-24 Plugins .............................................................................................29
6.1 Plugin window ......................................................................................................................................... 29
6.2 Connecting to the processor ................................................................................................................... 30
6.3 Key features............................................................................................................................................. 31
6.3.1 Master control................................................................................................................................. 31
6.3.2 Configuration/preset selection........................................................................................................ 32
6.3.3 Inputs............................................................................................................................................... 32
6.3.4 Input selection................................................................................................................................. 32
6.3.5 Routing matrix................................................................................................................................. 33
6.3.6 Outputs............................................................................................................................................ 33
6.4 Plugin configuration guide....................................................................................................................... 34
6.4.1 Signal flow –miniDSP-2x4-HD plugin .............................................................................................. 34
6.4.2 Signal flow –DDRC-24 plugin .......................................................................................................... 35
6.4.3 Stereo playback ............................................................................................................................... 36
6.4.4 Subwoofer integration (2.1 system)................................................................................................ 37
6.4.5 Dual subwoofers.............................................................................................................................. 38
6.4.6 Stereo supporting woofers.............................................................................................................. 39
6.4.7 Two-way active speaker .................................................................................................................. 40
6.4.8 Subwoofer control / multisub ......................................................................................................... 41
7Dirac Live...............................................................................................................................................42
7.1 How Dirac Live works .............................................................................................................................. 42
7.2 Software installation for Dirac Live ......................................................................................................... 43
7.2.1 Download and install Dirac Live ...................................................................................................... 43
7.2.2 Install the DDRC-24 plugin............................................................................................................... 43
7.3 Activating Dirac Live ................................................................................................................................ 43
7.4 Switching between miniDSP-2x4-HD and DDRC-24 ................................................................................ 46
7.5 Dirac Live Calibration............................................................................................................................... 47

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8Plugin Reference....................................................................................................................................48
8.1 Input channel strips................................................................................................................................. 48
8.1.1 Standard version only...................................................................................................................... 48
8.1.2 Dirac Live version only..................................................................................................................... 49
8.2 Routing .................................................................................................................................................... 49
8.3 Output tab ............................................................................................................................................... 50
8.3.1 Channel strip layout......................................................................................................................... 50
8.3.2 Channel label................................................................................................................................... 50
8.3.3 Level meter and gain control........................................................................................................... 50
8.3.4 Parametric EQ.................................................................................................................................. 51
8.3.5 Crossover......................................................................................................................................... 53
8.3.6 Compressor...................................................................................................................................... 55
8.3.7 FIR (miniDSP-2x4-HD plugin only) ................................................................................................... 56
8.3.8 Invert and mute............................................................................................................................... 56
8.3.9 Time delay ....................................................................................................................................... 56
8.4 Custom biquad programming.................................................................................................................. 57
8.4.1 What’s a “biquad?........................................................................................................................... 57
8.4.2 Using custom biquad programming ................................................................................................ 57
8.4.3 Biquad design software................................................................................................................... 59
8.5 FIR filtering and design (standard version only)...................................................................................... 60
8.5.1 FIR filtering overview....................................................................................................................... 61
8.5.2 FIR filter design software................................................................................................................. 61
8.5.3 Filter file format............................................................................................................................... 61
8.5.4 Loading filter coefficients ................................................................................................................ 62
8.6 Working with configurations................................................................................................................... 63
8.6.1 Changes to processing parameters ................................................................................................. 63
8.6.2 Selecting a configuration................................................................................................................. 63
8.6.3 Saving and loading configurations................................................................................................... 64
8.6.4 Restoring to defaults ....................................................................................................................... 64
8.7 Keyboard shortcuts ................................................................................................................................. 65
9Additional Information ..........................................................................................................................66
9.1 Specifications........................................................................................................................................... 66
9.1.1 All versions....................................................................................................................................... 66
9.1.2 Flex –single-ended analog I/O ........................................................................................................ 67
9.1.3 Flex/Balanced –balanced analog I/O.............................................................................................. 67
9.1.4 Flex/Digital –analog input, digital output....................................................................................... 68
9.2 Plugin and DSP upgrade .......................................................................................................................... 69
9.3 Firmware upgrade ................................................................................................................................... 70
9.3.1 Windows.......................................................................................................................................... 70
9.3.2 macOS / OS X................................................................................................................................... 72
9.4 Trouble-shooting ..................................................................................................................................... 74
9.4.1 Audio issues –standard version...................................................................................................... 74
9.4.2 Audio issues –Dirac Live version..................................................................................................... 75
9.4.3 Solving connectivity issues –Dirac Live version.............................................................................. 76
9.5 Obtaining support.................................................................................................................................... 77

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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 support.minidsp.com.
System Requirements –standard version
To configure the standard version of the miniDSP Flex audio processor without Dirac Live, you will require a
Windows PC or Apple Mac computer with the following minimum specification:
Windows
•Microsoft• ® Windows® 7/8.1/10/11
•At least a dual core i3, i5, or i7 processor
•At least 2 GB RAM (4 GB or more preferred)
•One free USB 2.0 port
•Internet connection
macOS
•OS X 10.8 or higher, macOS 10.12 or higher
•At least a dual core i3, i5, or i7 processor, or an ARM processor (M1/Pro/Max)
•At least 2 GB RAM (4 GB or more preferred)
•One free USB 2.0 port
•Internet connection
System Requirements –with Dirac Live upgrade
To configure the miniDSP Flex audio processor with Dirac Live upgrade, you will require a Windows PC or Apple
Mac computer with the following minimum specification:
Windows
•Microsoft• ® Windows® 10/11, latest version with all updates
•At least a dual core i3, i5, or i7 processor
•At least 2 GB RAM (4 GB or more preferred)
•Two free USB 2.0 ports
•Internet connection
macOS
•macOS 10.14 Mojave or later, latest version with all updates
•At least a dual core i3, i5, or i7 processor, or an ARM processor (M1/Pro/Max)
•At least 2 GB RAM (4 GB or more preferred)
•Two free USB 2.0 ports
•Internet connection

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Disclaimer/Warning
miniDSP cannot be held responsible for any damage that may result from the improper use of this product or
incorrect configuration of its settings. As with any other product, we recommend that you carefully read this
manual and other technical notes to ensure that you fully understand how to operate this product. The miniDSP
audio processor is a powerful tool, and misuse or misconfiguration, such as incorrectly set gains or excessive
boost, can produce signals that may damage your audio system.
As a general guideline, you should perform the initial configuration of the miniDSP audio processor before
enabling audio through any connected output device or amplification. Doing so will help ensure that the
software is correctly configured.
Finally, note that the miniDSP audio processor is a very flexible device, and many of the questions we receive at
the tech 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
support. Thanks 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.
FCC Class B Statement
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.

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CE Mark Statement
The miniDSP Flex has passed the test performed according to European Standard EN 55022 Class B.
A note 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. Use the
View menu (Preview on Mac) or the
bookmarks sidebar (Adobe reader on Mac and
Windows) to view this table of contents.
Acknowledgments
Dirac® and Dirac Live® are trademarks owned by Dirac Research AB.
ASIO® is a registered trademark of Steinberg Media Technologies GmbH.
LDAC™and LDAC logo are trademarks of Sony Corporation.
aptX™is a trademark of Qualcomm Technologies International, Ltd.
Bluetooth® is a registered trademark of Bluetooth SIG.

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1PRODUCT OVERVIEW
Thank you for purchasing a miniDSP Flex high-resolution
1
audio processor. The Flex combines the best of our
much-loved 2x4HD and DDRC-24 compact processors but adds an additional SPDIF input, Bluetooth streaming
with LDAC™and aptX™ HD codecs, and an OLED front panel with physical volume control. Of course, this
compact processor includes a full suite of miniDSP’s powerful audio processing tools and flexible I/O routing.
To allow for customers’ varying needs while maintaining the compact size, we have re-architected the I/O
section to allow different input-output versions to be easily produced. Versions currently available include
analog I/O on RCA, balanced analog I/O on TRS, and analog in/digital out. More are planned, so please refer to
the Flex product page for the current list.
Dirac Live has proven very popular with our customers purchasing dedicated Dirac Live-capable devices. The
miniDSP Flex can be purchased together with an optional Dirac Live upgrade, or can easily be upgraded later.
Despite its size, this pint-sized powerhouse packs in a lot of features, so please read the details in this manual
(and the accompanying Dirac Live manual if applicable) carefully.
1
The miniDSP SHD Series processors operate with 32-bit 96 kHz resolution.

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1.1 DIRAC LIVE UPGRADE
The miniDSP Flex can be upgraded to run Dirac Live® room correction. This requires an additional purchase for
the Dirac Live license. You can either purchase the Flex with Dirac Live already activated, or purchase the Dirac
Live upgrade at a later time from our webshop:
•https://www.minidsp.com/products/dirac-series/flex-dirac-upgrade
Note that each miniDSP Flex requires its own Dirac Live license. It is not possible to transfer licenses between
units, to use a standalone Dirac Live license purchased from Dirac Research with the Flex, or transfer a Dirac Live
license from a different miniDSP product over to a Flex.
1.2 TYPICAL APPLICATIONS
The miniDSP Flex has a wide range of applications in home and professional audio. This section illustrates a few
of them.
Figure 1 shows the miniDSP Flex used as a digital preamp with subwoofer integration. The Flex provides accurate
and flexible integration between the subwoofers and the main speakers as well as comprehensive EQ and tuning
options. This is a very cost-effective way to build a complete audio system that includes all the benefits of
modern DSP technology. Add the optional Dirac Live software upgrade for world-class room correction.
Figure 1. miniDSP Flex as preamp with subwoofer integration and room correction

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Figure 2 illustrates a similar use of the Flex as a digital preamp, but the output channels have instead been
configured to act as crossover for a pair of active 2-way speakers. Amplification can be via a multichannel power
amplifier as shown, or a pair of stereo amplifiers.
In Figure 3, the miniDSP Flex has been used as an accessory in a home theater system, to manage multiple
subwoofers. Driven from the A/V receiver’s subwoofer output, the miniDSP Flex can be used to independently
adjust gain, delay and parametric EQ of each subwoofer for optimum multi-sub performance.
Figure 3. miniDSP Flex for multisub management
Figure 2. miniDSP Flex used as preamp, active crossover and room correction

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2SOFTWARE INSTALLATION
This section describes how to install the miniDSP software that you will need to configure and operate the
miniDSP Flex:
1. The USB driver and control panel. This is needed only for Windows.
2. miniDSP-2x4-HD plugin. This software is used to configure the standard (non-upgraded) version of the
miniDSP Flex. It is also used to activate the optional Dirac live upgrade. There are separate versions for
Windows and Mac.
If you have purchased the optional Dirac Live upgrade, you will need to activate it on your Flex as described in
Section 7, Dirac Live.
2.1 DOWNLOAD THE MINIDSP SOFTWARE
If you purchased your processor directly from miniDSP, your software will be available from the User Downloads
section of the miniDSP website when your order ships. To access the download, you will need to be logged into
the website with the account you created when purchasing.
If you purchased your processor from a miniDSP dealer, you will receive a coupon together with the product.
Redeem this coupon 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:
Navigate to the miniDSP Flex section. Download the zip file under the heading miniDSP Flex.
After downloading, unzip the file (for Windows, right-click and select “Extract All...”; on Mac, double-click on it).
The unzipped download has a name like miniDSP2x4Flex_v1_01. (The version number embedded in the folder
name may be different.)

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2.2 WINDOWS
2.2.1 Possible Windows installation issues
The miniDSP software requires that a number of other software frameworks be installed. These packages should
be installed automatically, but you can manually install them if you receive an error message that required
software is missing.
•Microsoft .NET framework (version 3.5 or later)
•Microsoft Visual C++ 2010 Redistributable Package: for x86 (32-bit Windows) or x64 (64-bit Windows).
2.2.2 Install the miniDSP-2x4-HD plugin
3. Navigate to the 2x4HD folder of the software download.
4. Double-click on the plugin installer to run it. It will be named miniDSP-2x4-HD.exe. We recommend that
you accept the default installation settings.
2.2.3 Install the UAC2 driver
1. Connect the processor to the computer using the supplied USB cable, and power it on.
2. Navigate to the WinDrivers folder of the software download and double-click on the driver installer:
•miniDSP_UAC2_v4.82.0_2020-06-09_setup.exe for Windows 7 or later
(The version number and date embedded in the filename may be different.)
We recommend accepting the default installation location. Once driver installation completes, click Finish.
Note: the first time you run the miniDSP-2x4-HD plugin and the Dirac Live application, you may see a Windows
Firewall warning such as the one below. Ensure that “Private networks...” is checked and “Public networks...” is
not checked. Then click on “Allow access.” This warning dialog may appear more than once.

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2.3 MAC
2.3.1 Possible Mac installation issues
If double-clicking on an installer brings up a message that the installer cannot run, use this alternate method
(note that the name of the installer will be MiniDSP-2x4-HD.pkg or DDRC-24.pkg, not MiniDSP_Plugin.pkg as
shown in the screenshots):
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.”
2.3.2 Install the plugin
1. Navigate to the Plugins folder of the software download and then to the Mac folder.
2. The installer is named miniDSP-2x4-HD.pkg. 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 plugin, locate it 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.

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3HARDWARE OVERVIEW
3.1 REAR PANEL
3.1.1 miniDSP Flex
1. DC power. The supplied 12 VDC power supply includes a set of interchangeable power pins for USA, UK,
Europe and Australia. Fit the correct pins for your country. Connect the DC plug to the 12 VDC power
socket.
Apply power to the processor only after all input and output connections have been made.
2. USB port for control and audio streaming. Connect to an available USB port on your computer. This port
can also be connected to a network streamer with USB output for audio playback.
3. Bluetooth antenna. Screw on the supplied Bluetooth antenna here.
4. Optical digital input. Connect a digital source using a TOSLINK optical cable. Sample rates from 32 up to
216 kHz are supported.
5. Coax digital input. Connect a digital source using an RCA cable. Sample rates from 32 up to 216 kHz are
supported. The three digital inputs can be individually selected with the front panel encoder or the remote
control.
6. Analog inputs. Connect an analog source here using RCA cable. Typically, the left channel is connected to
input 1 and the right channel is connected to input 2. See Specifications for maximum input voltages.
7. Analog outputs. Connect equipment such as a power amplifier and subwoofer using RCA cables. Typically,
output 1 is the left channel and output 2 is the right channel. See Section 6.4 for a variety of other
connections. See Specifications for maximum output voltages.

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3.1.2 Flex/Balanced
1. DC power. The supplied 12 VDC power supply includes a set of interchangeable power pins for USA, UK,
Europe and Australia. Fit the correct pins for your country. Connect the DC plug to the 12 VDC power
socket.
Apply power to the processor only after all input and output connections have been made.
2. USB port for control and audio streaming. Connect to an available USB port on your computer. This port
can also be connected to a network streamer with USB output for audio playback.
3. Bluetooth antenna. Screw on the supplied Bluetooth antenna here.
4. Optical digital input. Connect a digital source using a TOSLINK optical cable. Sample rates from 32 up to
216 kHz are supported.
5. Coax digital input. Connect a digital source using an RCA cable. Sample rates from 32 up to 216 kHz are
supported. The three digital inputs can be individually selected with the front panel encoder or the remote
control.
6. Analog inputs. Connect an analog source here. The input jacks are balanced TRS (1/4” tip-ring-sleeve)
connectors, so typically XLR to TRS adapter cables would be used. Alternatively, RCA to TRS adapter cables
can also be used. Typically, the left channel is connected to input 1 and the right channel is connected to
input 2. See Specifications for maximum input voltages.
7. Analog outputs. Connect equipment such as a power amplifier or active speakers and subwoofer. The
output jacks are balanced TRS (1/4” tip-ring-sleeve) connectors, so typically TRS to XLR adapter cables
would be used. Typically, output 1 is the left channel and 2 is the right channel. See Section 6.4 for a variety
of other connections. See Specifications for maximum output voltages.

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3.1.3 Flex/Digital
1. DC power. The supplied 12 VDC power supply includes a set of interchangeable power pins for USA, UK,
Europe and Australia. Fit the correct pins for your country. Connect the DC plug to the 12 VDC power
socket.
Apply power to the processor only after all input and output connections have been made.
2. USB port for control and audio streaming. Connect to an available USB port on your computer. This port
can also be connected to a network streamer with USB output for audio playback.
3. Bluetooth antenna. Screw on the supplied Bluetooth antenna here.
4. Optical digital input. Connect a digital source using a TOSLINK optical cable. Sample rates from 32 up to
216 kHz are supported.
5. Coax digital input. Connect a digital source using an RCA cable. Sample rates from 32 up to 216 kHz are
supported. The three digital inputs can be individually selected with the front panel encoder or the remote
control.
6. Analog inputs. Connect an analog source here using RCA cable. Typically, the left channel is connected to
input 1 and the right channel is connected to input 2. See Specifications for maximum input voltages.
7. Digital outputs. Connect to a DAC, a home theater receiver, or active speakers with digital input. Each
digital connection output carries two output channels –output channels 1 and 2, or output channels 3 and
4. The TOSLINK and SPDIF outputs for each pair of channels carry the same signal and are both active at the
same time. The digital sample rate is 96 kHz if using the 2x4HD plugin (without Dirac Live) and 48 kHz if
using the DDRC-24 plugin (with Dirac Live).

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3.2 FRONT PANEL
The front panel display shows current volume, selected preset, input source, mute, and Dirac Live status (if
activated).
•To change the volume, rotate the encoder knob. Volume changes in 0.5 dB steps. Minimum volume is -127.5
dB and maximum volume is 0.0 dB.
•To change the selected preset, press the encoder knob once, then rotate until the desired preset number is
displayed. Either press the encoder again or wait for a second. The display will show “Pls wait…” while the
new preset is being loaded. The display will return to normal with the new preset number.
•To change input source, press the encoder knob twice. The display will change to show the current input
source in large letters. Rotate the encoder knob until the desired input source is displayed, then press the
encoder knob or wait for a second. The display will return to normal with the new input displayed.
•To turn Dirac Live filtering on and off (if it is activated), press the encoder knob three times. The display will
change to show either “Dirac On” or “Dirac Off” in large letters. Rotate the encoder knob until the desired
selection (on or off) is displayed, then press the encoder knob or wait for a second. The display will return to
normal with the Dirac Live status:
•To mute output, press and hold the encoder knob. When the display changes to show “Mute?,” release the
knob. To unmute, repeat this procedure.
•To put the miniDSP Flex into standby, press and hold the encoder knob. When the display changes to show
“Standby?,” release the knob. To take it out of standby, press the encoder knob.
All these operations can also be performed with the remote control.

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4PLAYING AUDIO
When delivered, the Flex is configured for stereo playback with no audio processing enabled. Output 1 carries
the left channel and output 2 carries the right channel.
4.1 DIGITAL SOURCES
All versions of the miniDSP Flex have SPDIF (on RCA/coax) and TOSLINK optical digital inputs. To play from either
of these sources, use the front panel knob or remote control to select SPDIF or TOSLINK.
4.2 ANALOG SOURCE
The miniDSP Flex has at most one stereo analog input. Depending on the version, this may be RCA (single-
ended) or TRS (balanced). To play from the analog input, use the front panel knob or remote control to select
Analog.

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4.3 BLUETOOTH
The miniDSP Flex includes the LDAC™ and aptX™ HD Bluetooth codecs
2
for the high-fidelity Bluetooth™audio.
LDAC is an audio coding technology developed by Sony that enables the transmission of High-Resolution (Hi-Res)
Audio content, even over a Bluetooth connection. Unlike other Bluetooth compatible coding technologies such
as SBC, it operates without any down-conversion of the Hi-Res Audio content
3
, and allows approximately three
times more data
4
than those other technologies to be transmitted over a Bluetooth wireless network with
unprecedented sound quality, by means of efficient coding and optimized packetization.
LDAC is supported on recent Android devices. If your device does not support LDAC, you can still pair it with the
Flex, but Bluetooth audio will use a lower bitrate codec.
aptX™ HD is designed to deliver high definition (HD) audio over Bluetooth, to help you get the very most from
your music.
Pairing your mobile device with the miniDSP Flex is essentially the same as pairing it with other Bluetooth audio
devices such as headphones or your car.
To put the Flex into pairing mode:
1. Press the encoder button on the Flex twice and rotate it until the display shows “Bluetooth.”
2. Press and hold the encoder and the display will change to “BTPairing.” The Flex is now in pairing mode.
3. Open the Bluetooth Settings on your mobile device to pair with the Flex. The exact appearance will vary
depending on your specific device, but this series of screenshots illustrates a typical sequence:
2
A codec (short for “coder/decoder”) is the algorithm that is used to compress the audio stream for transmission over
Bluetooth and then to decode it in the receiver.
3
Excluding DSD format contents.
4
In comparison with SBC (Subband Coding) when the bitrate of 990kbps (96/48kHz) or 909kbps (88.2/44.1kHz) is selected.