What's that Behringer DCX2496 all about ?

December 10th, 2006 : translation of this website is in progress, as it is a long job please be patient.

Introduction Weak points in many loudspeaker systems are very often the passive crossover and the drivers time alignement respectively to each other. Ideal solution is very difficult not to say impossible to achieve for the average DIYer audiophile, but the day has come which allows them fine tuning their system thanks to digital crossovers if used correctly. The solution we will consider hereafter is the user friendly Behringer ULTRADRIVE PRO DCX2496. In a nutshell : the DCX2496 is THE affordable high performance DAC coupled with a powerful loudspeaker management processor. It’s the ultimate tool for those seeking audio perfection. Before you go and read it's specifications on the manufacturer's webpage let's introduce you the DCX2496 and the way of using it properly in your beloved system.

Short description The DCX2496 is a high-precision 24-Bit/96 kHz digital loudspeaker management system with a handfull of functions and a wonderful built-in digital to analog converter using the AKM4393 from Asahi Kasei you can find in many very high-end DACs. For less than US$300, the DCX2496 is currently the only tool for utimate set-up of a multi-amplified system proposed at a bargain price due to quality mass production. For that steal price you get four different mono and stereo output operating modes, all with individual crossover filter types (Butterworth, Bessel and Linkwitz-Riley) with selectable roll-off characteristics from 6 to 48 dB/octave. The delays for all inputs and outputs are adjustable. This allows you to manually or automatically adjust the drivers delay for room temperature, phase and time alignment differences. An additional sum signal is easily derived from the A/B/C inputs. Not happy with the front panel user interface ? You may then enjoy setting up your system through a Windows® (via RS-232 port) editing software available for download free of charge on Behringer's webpage. Want to link several DCXs ? Use the RS-485 network interface for cascading them. No matter what the future brings, its open architecture assures easy software updates. A PCMCIA slot allows you to store all your settings and recall them anytime you change the location virtually taking your active crossover with you. Furthermore, the DCX features a microphone input which shall be used for achieving accurate time alignment for your very own speakers. Behringer does sell a calibrated microphone ECM8000 for this purpose.

Well, it sounds nice but what are the advantages for us audiophiles ? The DCX2496 uses ultimate technology in digital signal processing and thus we will take advantage of its extraordinary powerful digital to analog converter. In other words we will process the signal in the digital domain (i.e. without the tiniest degradation) and then convert it to analog at the very end of the signal path, just before the amplifiers. Avoiding multiple and useless signal conversions results in a crystal clear sound right out of the DACs. Let's figure out what happens when you are using a DCX through it's analog inputs :

  1. CD is decoded in your player which will convert digital signal to analog (either you are using an integrated player or a separate DAC)
  2. analog signal is then driven to your suposedly transparent preamplifier or volume control
  3. analog signal is then fed to the analog inputs of the DCX
  4. For crossovering purposes analog signal will then be converted back to digital.
  5. after having been separated into low, mid and high frequencies by the DSP, digital signal will be then converted back to analogue to feed your amps.
Problem is that today's 24bits DACs and ADCs will add ditorsion to the delicate low level audio details, exactly where the lifelikeness of music is. In other terms, life and details will be litteraly wiped off by too many conversions. As a rough comparison remember what happened to your preferred movie when you tried to duplicate an already copied VHS in the good old days : loss of details and constrast, addition of video noise and hiss. This is what happens here.

Then, is it the ultimate or ideal tool we all are looking for ? Well, yes and no. The engineers who designed the DCX are extremely smart when it 's about digital, but the analog output circuits clearly need to be improved sonically speaking. In fact the DCX2496 is a professional product meant for stage sound, PA or DJ'ing . Thus Behringer didn’t pay much attention to using top of the range audio grade op amps and capacitors or optimised analog circuitry. Furthermore, an ordinary quartz oscillator is used when it is most important for the DSP to work with an ultra low jitter clock. Once the tweaks described in these pages have been applied this baby really rocks and will compare with the best crossovers and DA converters available today, whatever their price is. For the faint hearted Selectronic has elaborated kits based on the author's experiment and advises. They are easy to assemble and to install, and the results are outstanding.