The XO4 is a 4-in 8-out audio management system from XTA, in collaboration with Funktion One, offers advanced processing capabilities and improved performance along with extra features as standard.
 
Features:
4 inputs and 8 outputs - native processing now runs at 96k resulting in wider bandwidth (over 30kHz).
Flexible routing matrix - in addition to standard fixed configurations such as 4 x 2 way (standard configs are still implemented), any output may be fed from any input or the sum of inputs. Edit buttons show routing instantly when pressed.
Extended processing capabilities - 9 (previously 5) full bandwidth parametric bands available on every output, all switchable between PEQ, high and low shelving responses.
Input EQ is now offered as standard - 8 bands of fully parametric EQ on each input channel.
Further extended processing capabilities - crossover filters on each output now offer 48dB/Oct. responses, on top of the previously available 1 to 4dB/Octave options. A gentle 6dB/Octave roll-off response is also now included.
Legendary XTA program limiters with automatic and manual time constant facilities.
New additional ''D-Max'' limiter with look ahead processing allows attack time of standard limiter to be optimised for best audio quality, whilst still being able to set a ceiling on the maximum output of any channel.
Delay memory allows for up to 650mS from any input to any output - extra fine delay resolution on outputs for driver alignment, in 30nS (0.1mm) steps!
Extended memory capacity - user memories now extended to a maximum of 55 which may be Input data, X-over data or both.
Library manager software available for design of OEM presets - design your crossover live whilst connected to the unit, and lock out any parameters as required to stop end user adjustment/viewing. No practical limit to the number of presets that may be stored (over and above the user memories).
Improved converters - lower noise and improved distortion figures.
AES Input accepts AES rates from 32k up to 192k via a sample rate converter. Front panel indication of AES selection and AES lock status.
AES Output (available special order as a product enhancement) sample rate fixed at 96k.
Familiar 226 style user interface with enhancements including menu shortcuts and quick access triple press editing to get the job done quickly. ALL functions are available though the front panel interface - NOTHING is just a remote facility.
Bigger 2 x 24 character display with new low profile buttons.
Auto switching power supply works across the world on all voltages. 
XO4A - Audiocore compatibility (Not available in the standard XO4), control up to 32 processors remotely via 3 Pin-XLR standard signal cable, using RS485 (wireless adaptor available).
 
DP4 Remote application offers the possibility to remote control up to 32 XO4A Loudspeaker Management Systems from your iPhone® or iPod Touch® or iPad®.  DP4 Mini is also available as a shrunk down application that allows read only access.