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miniDSP Ltd, Hong Kong / 

www.minidsp.com

 / Features and specifications subject to change without prior notice

 

35 

4.6

 

C

ROSSOVER

 

Available in

2x4 Advanced

2Way Advanced

2Way Advanced 21

4Way Advanced

Stereo Graphic EQ

4Way 

GEQ

 

 

Crossovers “split” the frequency band to send to different drivers. In a two-way loudspeaker, for example, a 

low 

pass

 filter is used to remove high frequencies from the signal sent to the woofer, and a 

high pass

 filter is used to 

remove low frequencies from the signal sent to the tweeter. The above screenshot shows a two-way crossover. 
In a four-way crossover, the signal is split into four frequency bands: 

 

In most plugins, each output channel has a high pass filter and a low pass filter, each of which can be set to one 
of a range of filter types and slopes, or individually bypassed. Clicking on the bars labeled “CH1 Bandpass Filter 
OUT1,” and so on displays the filter parameters for that output channel. 

Unlike conventional analog crossovers, the flexibility of DSP allows a completely arbitrary mix of different filter 
slopes and types. Filters can be set at any frequency, or even disabled completely. This allows maximum 
flexibility in matching your crossover to the acoustic characteristics of the loudspeaker drivers that you are 
using. 

Summary of Contents for BALANCED 2X4

Page 1: ...Ltd Hong Kong www minidsp com Features and specifications subject to change without prior notice 1 BALANCED 2X4 2 IN 4 OUT BOXED AUDIO PROCESSOR BALANCED KIT 2 IN 4 OUT AUDIO PROCESSOR BARE BOARD User...

Page 2: ...itial version 24 09 2010 V1 1 Sensitivity Jumper clarifications 24 09 2010 V1 2 Updated various sections 23 12 2010 V1 3 Input Output sensitivity tables 23 03 2011 V1 4 miniUSB 5 pin connector 25 08 2...

Page 3: ...the plugin 14 2 3 Go into online mode 16 2 4 Perform initial configuration 17 2 5 Get audio up and running 17 2 5 1 Make audio connections 17 2 5 2 Reconnect to the plugin 18 2 5 3 Initial audio chec...

Page 4: ...mming 40 4 12 3 The plugin calculator 42 4 12 4 Biquad calculation spreadsheet 42 4 12 5 Room EQ Wizard REW 42 4 12 6 Active Crossover Designer ACD 42 5 Kit Documentation 43 5 1 Board layout and featu...

Page 5: ...based Mac with 1 GHz or higher processor clock speed 512 megabytes MB of RAM or higher Keyboard and mouse or compatible pointing device Mac OS X 10 4 or higher USB 2 0 port Adobe AIR environment late...

Page 6: ...n 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...

Page 7: ...THE MINIDSPCONCEPT The miniDSP concept is one hardware unit one software plugin audio processing solution This concept leverages the inherent flexibility of DSP digital signal processing to deliver a...

Page 8: ...e board can be integrated into any build that requires the addition of flexible yet cost effective audio processing miniDSP make a large and growing number of hardware platforms for particular needs I...

Page 9: ...endent crossovers filters with a wide range of filter slopes up to 48 dB octave on all four outputs and a matrix mixer Two way active loudspeakers are among the wide range of applications supported by...

Page 10: ...ed The new 2x4 crossover plugin provides parametric EQ on both inputs and on all four outputs fully independent crossovers filters with a wide range of filter slopes up to 48 dB octave on all four out...

Page 11: ...pass filters For more information see the datasheet 1 3 4 Subwoofer applications For subwoofer applications we usually recommend the use of the 2x4 Advanced plugin because of its flexibility and abil...

Page 12: ...puts 3 and 4 this is essentially the same as a two way crossover To accomplish this configuration use the matrix mixer to send input channel 1 to outputs 1 and 2 and input channel 2 to outputs 3 and 4...

Page 13: ...x sends input channel 1 to all four output channels Two to four subwoofers from dual mono signal e g AVR Some A V processors and A V receivers provide two subwoofer outputs You can send each input to...

Page 14: ...ning 6 Fine tune your configuration 7 Continue to operate offline 2 1 DOWNLOAD AND INSTALL THE PLUGIN When your order ships your ordered plugin will be available from the User Downloads section of the...

Page 15: ...DSP hardware unit Audio flows through the diagram from the inputs on the left to the outputs on the right Clicking on each block will show its control interface in the detail pane underneath it Detail...

Page 16: ...Start the plugin if it is not already running and click on the Connect Synchronize button The following dialog will appear Click on the Restore to Default button This is essential the first time you c...

Page 17: ...vertently restore the miniDSP to default settings For more information on configurations see System settings 2 5 GET AUDIO UP AND RUNNING With the initial configuration done and now that you are famil...

Page 18: ...in is performing the intended function For example if you are implementing a two way crossover confirm that the tweeter is playing high frequencies and that the woofer is playing low frequencies If yo...

Page 19: ...ttings for more information on configurations 2 7 CONTINUE TO OPERATE OFFLINE With your miniDSP hardware and software configured you can continue to operate the miniDSP in offline mode that is without...

Page 20: ...n follow the installation procedure below according to your computer type Note the Adobe Air framework may need a network connection the first time the plugin is used If the plugin does not start prop...

Page 21: ...rder that you can make changes to the settings 2 Under the text Allow applications downloaded from click on Anywhere Then download and install the following programs You will need to accept the licens...

Page 22: ...able as an option when purchasing the miniDSP Balanced 2x4 orBalanced Kit Fit the correct pins for your country and connect the DC plug to the 12 VDC power socket Older units use a two terminal Phoeni...

Page 23: ...The USB cable can safely be connected and disconnected while the miniDSP is powered on 3 2 3 Audio inputs and outputs Input connections are made to Phoenix terminal blocks on the front panel of the mi...

Page 24: ...s the connections for balanced input and output S is the shield wire and and are the positive and negative signal leads For making unbalanced connections take note of the wiring in the following diagr...

Page 25: ...be made quickly by cutting XLR XLR or microphone cables in two The two halves are then used for input and output as shown here If connecting to equipment with RCA connectors suitable cabling can often...

Page 26: ...ced or balanced input 4V position The maximum input signal voltage allowed before clipping the A D convertor is 4 0 Volts RMS for either unbalanced or balanced input Note that the input sensitivity ju...

Page 27: ...on Loads a configuration file This changes all the settings to match the settings saved into the file o If the plugin is in online mode the configuration settings will be downloaded immediately to the...

Page 28: ...maximum of 331 frequency points are allowed For an example of the file format go to the Help screen and click on the Import Template button Once the response is loaded it appears in the frequency res...

Page 29: ...ts are in increments of 0 1 dB In all other plugins gain adjustments are in increments of 1 dB Meter Displays the current input signal level The level is displayed in dB FS relative to maximum input v...

Page 30: ...plugins gain adjustments are in increments of 1 dB Meter Displays the current output signal level The level is displayed in dB FS that is relative to full scale output voltage which is 0 9 V RMS Make...

Page 31: ...cations some slopes e g 12 dB octave typically require that one of the output channels be inverted In subwoofer applications this can be helpful to improve integration with the main speakers The Mixer...

Page 32: ...rall response curve of all EQ bands Hovering the mouse over the curve brings up an overlay with the frequency and gain at that frequency Control sliders The sliders in the lower half of the control pa...

Page 33: ...ter and low shelf filter The top section of the control panel shows the overall response curve of all PEQ filters in the block Hovering the mouse over the curve brings up an overlay showing the freque...

Page 34: ...y at which the gain is half of the set value Gain For the PEAK filter type this is the gain in dB at the center frequency For the HIGH_SHELF and LOW_SHELF filter types this is the gain in dB reached a...

Page 35: ...shows a two way crossover In a four way crossover the signal is split into four frequency bands In most plugins each output channel has a high pass filter and a low pass filter each of which can be se...

Page 36: ...from full on to full off as determined by the filter slope Filter type Selects the type and slope of the filter The steeper the slope the more quickly frequencies above or below the cutoff frequency...

Page 37: ...n the Bypass 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 T...

Page 38: ...Bessel 12 dB octave Linkwitz Riley 24 dB octave Note the Mixer plugin has the high pass and low pass filters in separate blocks The net result is the same 4 9 MATRIX MIXER Available in Mixer The matr...

Page 39: ...of the keyboard for many operations Tab The Tab key moves the focus to the next user interface element A light blue surrounding box indicates the user interface element with the focus if it is a text...

Page 40: ...basic interface implement a Linkwitz transform or mix crossover and filtering biquads in the same block 4 12 1 What s a biquad A biquad is the basic unit of processing that is used to create digital f...

Page 41: ...ad coefficients click on the Process button for them to take effect Parametric EQ file import REW integration All filters in the block can be set at once by importing a coefficient file from Room EQ W...

Page 42: ...ore 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 fbfi...

Page 43: ...UMENTATION The miniDSP Balanced Kit is a bare circuit board that can be incorporated into your own chassis and combined with other electronics components This section documents the supported connectiv...

Page 44: ...nix connector or the round barrel connector depending on the version as shown here Double check that power connections are the correct polarity before applying power 5 2 2 Stacked with miniDIGI When s...

Page 45: ...pinout of this header is shown below I2S also known as Inter IC Sound is an electrical serial bus used to interface digital audio devices at the chip and circuit board level Note that I2S is not a pl...

Page 46: ...ed by a black wire but once again DO check the manufacturer s spec of the connector to prevent any short circuits To make things simple we provide a suitable cable for purchase in the accessories sect...

Page 47: ...female connector can be purchased together with the kit board or separately from the Accessories section of our website The connection to the volume header must be performed with the board powered do...

Page 48: ...nerates its own master clock In this case the jumper must be in the Master position If the board is used with an external device that generates the I2S signals the board must slave to the external clo...

Page 49: ...dBu or 4 0 VRMS 14 dBu Jumper selectable input sensitivity ADC dynamic range un weighted 99 dB Input impedance 47 k each leg to ground Analog Audio Output 4 channels balanced on Phoenix connectors Max...

Page 50: ...Check that you are loading a file saved with the same plugin 5 No audio on outputs a Check the input meters are showing signal if not see item 6 b Check that master mute is not enabled c Check that t...

Page 51: ...to see if this issue has already been raised and a solution or solutions provided 2 Contact miniDSP via the support portal at minidsp desk com with a The specific product you are having an issue with...

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