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miniDSP Ltd, Hong Kong / 

www.minidsp.com

 / Features and specifications subject to change without prior notice

 

34 

6.5.4

 

Loading filter coefficients 

In 

File Mode

4.

 

Click 

Browse

, navigate to the file containing the filter coefficients, and open it. A dialog will appear 

confirming the number of coefficients loaded. 

5.

 

Confirm that the response curve is as you expect. 

6.

 

Press 

Send to DSP

. This will write the coefficients into the DSP's memory. 

7.

 

To clear the filter coefficients, click 

Unload FIR 

and then 

Send to DSP

 

In 

Manual Mode

8.

 

Cut and paste the coefficients from the text output of the design program.

 

9.

 

Press the 

Process 

button.

 

10.

 

Confirm that the frequency response graph is as you expect. 

11.

 

Press 

Send to DSP

. This will write the coefficients into the DSP's memory. 

12.

 

To clear the filter coefficients, click 

Clear Taps 

and then 

Send to DSP

 
 

If, after selecting a filter file or setting coefficients, the frequency response graph does not change as 
expected, make sure that the Bypass button is turned off. 

 

If you clear the filter taps, make sure that you also bypass the filter, otherwise there will be no audio 
through that channel. 

Содержание 2X4 HD

Страница 1: ...www minidsp com Features and specifications subject to change without prior notice 1 2X4 HD COMPACT 2 IN 4 OUT HIGH RESOLUTION AUDIO PROCESSOR 2X4 HD KIT 2 IN 4 OUT HIGH RESOLUTION AUDIO PROCESSOR CIR...

Страница 2: ...ion history Revision Description Date V1 0 First preliminary release version 15 January 2016 V1 1 Added kit board installers 31 January 2016 V1 2 Updated installation procedure 22 February 2016 V1 3 U...

Страница 3: ...Driver installation 12 3 2 Mac 13 3 2 1 Possible Mac installation issues 13 3 2 2 2x4 HD plugin installation 13 4 Hardware connectivity 14 4 1 Digital input 14 4 2 Analog inputs and outputs 14 4 3 US...

Страница 4: ...filter coefficients 34 6 6 Working with configurations 35 6 6 1 Online and offline mode 35 6 6 2 Selecting a configuration 35 6 6 3 Saving and loading configurations 36 6 6 4 Restoring to defaults 36...

Страница 5: ...r latest version Mac OS X Intel based Mac with 1 GHz or higher processor clock speed 512 megabytes MB of RAM or higher Keyboard and mouse or compatible pointing device USB 2 0 port Mac OS X 10 8 or hi...

Страница 6: ...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 install...

Страница 7: ...analog output channels Parametric EQ on all input and output channels Butterworth and Linkwitz Riley crossovers up to 48 dB octave and advanced biquad programming for an unlimited range of filters an...

Страница 8: ...the preamp as shown here The miniDSP 2x4 HD is a perfect solution for multi subwoofer management for home theater Driven from the A V receiver s subwoofer output the 2x4 HD can be used to adjust gain...

Страница 9: ...eters will be reset in the next step you can feel free to experiment at this point 3 Reset all parameters From the Restore menu select the Factory Default option This will reset all processing paramet...

Страница 10: ...t signal Gradually increase the volume until your hear audio quietly coming from the speakers Verify that the plugin is performing the intended function For example if implementing a two way crossover...

Страница 11: ...ins section and download the zip file under the heading miniDSP 2x4 HD1 Unzip the downloaded file on Windows right click and select Extract All on Mac double click Note the Adobe Air framework may ne...

Страница 12: ...er of the software download and double click on the appropriate installer miniDSP_UAC2_v2 29 0_ForWinXP_Vista exe for Windows XP and Vista miniDSP_UAC2_v3 34 0_ForWin7_8_10 exe for Windows 7 8 and 10...

Страница 13: ...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 2 2 2x4 HD plugin installation 1 Navigate to the Plugins folder of...

Страница 14: ...rates between 44 1 and 192 kHz are accepted Note the digital input accepts only a stereo PCM digital signal It does not accept encoded or multichannel digital audio such as Dolby Digital or DTS 4 2 A...

Страница 15: ...four output channels from the miniDSP 2x4 HD to the computer 4 4 DC POWER The supplied 12 VDC power supply includes a set of interchangeable power pins for USA UK Europe and Australia Fit the correct...

Страница 16: ...our own box and or combined with other boards such as power amplifiers This annotated photograph shows the main features of the board The only user accessible jumpers are used to set the analog input...

Страница 17: ...t selection can be done with a remote control see Infrared Remote Control on page 38 If desired however the plugin can remain connected during use for real time live control of all audio processing Th...

Страница 18: ...d any changes to processing parameters will be downloaded immediately in real time That is the user interface is now live Synchronize and Upgrade This is similar to Synchronize Config but also upgrade...

Страница 19: ...plays two input channel control strips and the routing matrix 6 2 1 Input selection When the plugin is connected to the 2x4 HD the currently selected input appears next to the Inputs label Click on th...

Страница 20: ...me The plugin must be in online mode to display signal levels Gain adjustment The gain of each channel can be adjusted by moving the Gain Adjustment slider or by typing the desired gain into the Curre...

Страница 21: ...channel is routed to outputs 1 and 2 and the right input channel is routed to outputs 3 and 4 to change the input and output channel labels see pages 20 and 22 For subwoofer integration the left and...

Страница 22: ...annel strip This label also appears on the Routing matrix To change the label click on it type a new label up to eight characters and press the Return key 6 3 3 Level meter and gain control Level mete...

Страница 23: ...ing the combined response of all enabled parametric filters on that channel For example the screenshot above shows a response curve created with a low shelf boost filter at 100 Hz a dip at 500 Hz and...

Страница 24: ...B_EQ filter reduces the number of available filters on that channel from ten to nine Frequency For the PEAK and SUB_EQ filter types this is the center frequency of the peak or dip For the HIGH_SHELF a...

Страница 25: ...three way speaker the midrange driver will use both the high pass and low pass filters Crossover filters can also be used to limit low frequency content delivered to a speaker or subwoofer to help pr...

Страница 26: ...types of filter Butterworth BW Available in 6 12 18 24 30 36 42 and 48 dB octave Butterworth crossover filters are 3 dB down at the cutoff frequency Linkwitz Riley LR Available in 12 24 36 and 48 dB...

Страница 27: ...pass button to see the curve as shown here In this example the threshold is set to 20 dB so the compressor will activate when the signal on that channel reaches 20 dB relative to full output The ratio...

Страница 28: ...described more in FIR filtering and design starting on page 32 6 3 8 Invert and mute Each channel can be inverted in polarity and individually muted When either of these options is selected the visua...

Страница 29: ...A biquad is the basic unit of processing that is used to create digital filters It can be described either with an equation or with a signal flow diagram as shown here A single biquad like this can pe...

Страница 30: ...is example illustrates the correct file format biquad1 b0 0 998191200483864 b1 1 9950521500467384 b2 0 996920046761057 a1 1 9950521500467384 a2 0 9951112472449212 biquad2 b0 0 999640139948623 b1 1 998...

Страница 31: ...y filter types to be calculated including notch filters Linkwitz transforms and filters with arbitrary Q factor Access this spreadsheet here requires Microsoft Excel http www minidsp com images fbfile...

Страница 32: ...s a file browser to select a file containing FIR filter coefficients See Filter file format below Unload FIR Deletes the currently loaded filter from the display and from the DSP memory Send to DSP Wr...

Страница 33: ...have 6 or more taps and can have no more than 2048 taps The decision on how many taps to allocate to each channel up to you and should be determined after working with an FIR filter design program se...

Страница 34: ...ients click Unload FIR and then Send to DSP In Manual Mode 8 Cut and paste the coefficients from the text output of the design program 9 Press the Process button 10 Confirm that the frequency response...

Страница 35: ...lly only The next time the plugin is synchronized to the processor the parameters will be downloaded to the processor as long as the Synchronize Config button is selected The configuration contained i...

Страница 36: ...line mode the new configuration data will be downloaded to the processor immediately If the plugin is in offline mode the configuration will be loaded into the user interface only and will be download...

Страница 37: ...the next A blue grey surrounding box usually indicates the user interface element with the focus Shift Tab moves the focus in the opposite direction Up down arrows The up down arrow keys and in some c...

Страница 38: ...USB connector is used both for streaming audio and configuration 7 1 MAC OS X Open the program Audio MIDI Setup in Applications Utilities The 2x4 HD will appear as miniDSP2x4n in the list on the left...

Страница 39: ...open the miniDSP UAC2 Control Panel from Start Menu miniDSP Ltd It has several panes described below 7 2 1 Status This panel shows the current sample rate of the 2x4 HD This setting cannot be changed...

Страница 40: ...igh amounts of CPU and memory and may not work on some machines If you do not require lowest latency we recommend that you do not depart from the default safe settings 7 2 4 Volume This panel contains...

Страница 41: ...Hong Kong www minidsp com Features and specifications subject to change without prior notice 41 There is a similar set of controls for the input channels 7 2 5 Info This panel shows information about...

Страница 42: ...he 2x4 HD can learn the control codes of your current remote if it supports one of the following remote control codes NEC Sony Philips RC6 To initiate the learning process drop down the IR Remote menu...

Страница 43: ...ctors Max input of 4V or 2V RMS jumper selectable Input impedance 10k THD N 0 003 RCA to USB Dynamic range 102dB Analog audio outputs Unbalanced analog audio 4 channels on RCA connectors Max output 2V...

Страница 44: ...MCU firmware first download and install the latest version of the 2x4 HD plugin from the User Downloads section of the miniDSP website DO NOT DISCONNECT THE USB CABLE OR POWER FROM THE 2x4 HD WHILE F...

Страница 45: ...folder and select the firmware file It will have a name like miniDSP2x4n_XMOS_v1 3 bin The version number may be different 5 Click on the Start button 6 You will get a progress bar as upgrade proceeds...

Страница 46: ..._Firmware myname ls miniDSP2x4n_XMOS_v0 13 bin miniDSP_UAC2_DFU_OSX readme txt mycomputer Firmware myname You see in the above list the name of the firmware file miniDSP2x4n_XMOS_v0 13 bin the version...

Страница 47: ...nager as a HID device 4 No audio or low audio on outputs a Check the cabling from the processor to your amplifiers b Check that your amplifiers are turned on and that any volume controls are turned up...

Страница 48: ...Cannot reload a configuration a Confirm the file format of your file xml b Confirm the version of the file 9 4 OBTAINING SUPPORT 1 Check the forums on miniDSP com to see if this issue has already bee...

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