background image

 

 

 

miniDSP Ltd, Hong Kong 

www.minidsp.com

 / Features and specifications subject to change without prior notice

 

31 

3.6

 

C

ROSSOVER

 

Available in

2x4 Advanced

2Way Advanced

2Way Advanced 21

4Way Advanced

 

 

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 the miniDSP 2x4 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 display

s 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 EQ901 Series

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

Page 2: ...12 V2 0 Updated and revised for Rev3 PCB 15 06 2014 V2 1 Merged with kit manual 30 06 2014 V2 2 Added 2x4 Advanced plugin 15 May 2015 V2 3 Removed obsolete plugins new product photographs 6 Oct 2015 V...

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

Page 4: ...adsheet 37 3 10 5 Room EQ Wizard REW 37 3 10 6 Active Crossover Designer ACD 37 4 Optimizing Gain Structure 38 5 Kit Documentation 39 5 1 Board layout and features 39 5 2 Expansion header and I2S conn...

Page 5: ...g device Mac OS X 10 8 or higher USB 2 0 port DISCLAIMER WARNING miniDSP cannot be held responsible for any damage that may result from the improper use or incorrect configuration of this product The...

Page 6: ...t contact miniDSP prior to use 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...

Page 7: ...verages the inherent flexibility of DSP digital signal processing to deliver a range of flexible but cost effective solutions Hardware unit In this case the hardware unit is the miniDSP 2x4 or miniDSP...

Page 8: ...ld that requires the addition of flexible yet cost effective audio processing miniDSP make a large and growing number of hardware platforms for particular needs If the 2x4 is not the most suitable har...

Page 9: ...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 this plugin For more information see the datasheet 2way Advance...

Page 10: ...puts and on all four outputs fully independent crossovers filters with a wide range of filter slopes up to 48 dB octave on all four outputs and a matrix mixer Three way and four way active loudspeaker...

Page 11: ...we usually recommend the use of the 2x4 Advanced plugin because of its flexibility and ability to handle many different subwoofer configurations This flexibility is provided by the use of the matrix m...

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: ...ends 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 any...

Page 14: ...ess 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 you ordered at the link below https ww...

Page 15: ...bar and select Pin to taskbar 2 1 2 Mac To install the plugin 1 Navigate to the Mac folder of the software download 2 The installer program is named MiniDSP_Plugin pkg The name will depend on the spec...

Page 16: ...elp The Synchronize button connects the user interface to the miniDSP hardware unit downloading configuration data and putting it into online mode The Master Mute button enables or disables all audio...

Page 17: ...ree USB port on your computer to the miniDSP 2x4 or kit board In the case of the kit see also USB connectivity The USB connection will power the miniDSP hardware as well as provide data communication...

Page 18: ...parameters You should save your configuration to a file on a regular basis to ensure that you do not lose your work if you inadvertently restore the miniDSP to default settings For more information on...

Page 19: ...ze option from the dialog box The miniDSP is now in online mode again 2 5 3 Initial audio check Power on your connected equipment first on the input side e g preamp then on the output side e g power a...

Page 20: ...quency and slope settings For subwoofer integration Measure the subwoofer with the microphone placed at the listening position Typically moving the subwoofer to find the best response without EQ will...

Page 21: ...B charger should be adequate Connect an auxiliary DC power supply to the 2 1mm DC power connector The power supply voltage can be in the range of 4 5 to 24 VDC enabling use of a wide range of power so...

Page 22: ...ard off or on please ensure that you a Turn the connected equipment off before disconnecting power from the miniDSP and b Connect power to the miniDSP before turning connected equipment on 2 8 2 Notes...

Page 23: ...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 24: ...sponse magnitude A 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...

Page 25: ...djustments 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...

Page 26: ...djustments 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 sure to keep t...

Page 27: ...t channel In crossover applications 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...

Page 28: ...rve 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 panel adjust the b...

Page 29: ...tion of the control panel shows the overall response curve of all six PEQ filters Hovering the mouse over the curve brings up an overlay showing the frequency and the gain at that frequency The exampl...

Page 30: ...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 31: ...ssover In a four way crossover the signal is split into four frequency bands In the miniDSP 2x4 plugins each output channel has a high pass filter and a low pass filter each of which can be set to one...

Page 32: ...al fact of course the crossover has a more or less gradual transition 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 sl...

Page 33: ...ave Linkwitz Riley 24 dB octave 3 8 MONO STEREO MODE Available in 2Way Advanced 21 The 2Way Advanced 21 plugin supports mixing of two output channels allowing this plugin to be used in 2 1 application...

Page 34: ...ection Up down arrows The up down arrow keys adjust the value of the parameter with the focus For example Input and output channel gain Crossover frequency and filter type PEQ filter frequency gain an...

Page 35: ...basic interface implement a Linkwitz transform or mix crossover and filtering biquads in the same block 3 10 1 What s a biquad A biquad is the basic unit of processing that is used to create digital f...

Page 36: ...biquad coefficients click on the Process button for them to take effect Parametric EQ file import REW integration All six filters can be set at once by importing a coefficient file from Room EQ Wizar...

Page 37: ...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 38: ...ted between them by opening the case and moving two jumpers A 0 9 V position The maximum input signal voltage allowed before clipping the A D convertor is 0 9 Volts RMS This position is typically used...

Page 39: ...DOCUMENTATION The miniDSP 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 connectivity a...

Page 40: ...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 plu...

Page 41: ...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 42: ...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 43: ...ates 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 clock...

Page 44: ...l processing ADC DAC resolution and sample rate 24 bit 48 kHz Analog Audio Input Unbalanced RCA Maximum input level 1 THD 0 9 VRMS RevA or 2 0 VRMS RevB ADC dynamic range un weighted 98 dB Input imped...

Page 45: ...Confirm the format of your file xml b 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 mast...

Page 46: ...o see if this issue has already been raised and a solution or solutions provided 2 Contact miniDSP via the support portal at support minidsp com with a The specific product you are having an issue wit...

Reviews: