DEQX

DEQX HDP Jensen Transformer Balanced Output Board A plug in board to add six Jensen Transformer balanced outputs to your HDP-4. $988.00	DEQX HDP-4 The DEQX HDP-4 flagship speaker correction, room correction, dsp crossover and digital preamplifier. $4,995.00
DEQX HDP-Express-II The DEQX HDP-Express II speaker correction, room correction, dsp crossover and digital preamplifier. $2,995.00	DEQX Reference Earthworks M23 Calibration Kit 'Better' DEQX calibration kit containing software, cables and Earthworks M23 measurement microphone. $645.00
DEQX Reference Earthworks M30 Calibration Kit 'Best' DEQX calibration kit containing software, cables and Earthworks M30 measurement microphone. $935.00	DEQX Standard Calibration Kit 'Standard' DEQX calibration kit containing software, cables and Behringer ECM8000 microphone. $199.00

DEQX (Digital EQualization and Crossover - aka Xover) products deserve a category all for themselves. There are very few products on the market which provide all of the functionality of a HDP-4 or HDP-Express-II processor. They provide speaker correction, room correction, recording equalization and crossover capabilities.

A DEQX calibration kit - which comprises the measurement microphone, cables and calibration software - is not included with the HDP-4 or HDP-Express II processor but is required for its operation. There are three choices - the Behringer is a good 'get started' unit, or suitable if you are only doing room correction. For any applications involving speaker correction Acoustic Frontiers recommends stepping up to one of the Earthworks mics - either the M23 or M30.