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Credo Audio System - EV 900 - active

Cutting edge technology

One of our most successful loudspeakers, the model 900 also available as active speaker with DSP crossover.

Active loudspeakers

There are some reasons for powered loudspeakers. Nevertheless, they have a relatively small share in high-end audio market. The largest market share have the passive loudspeakers.

We always were interested in this kind of loudspeakers. But there are some aspects we never liked:

  • Analog filter networks in a compact cirquit-design
  • Op-amp based line amplifier stages
  • Housing the electronics in the speaker
  • Compromises on power amplifiers and power supplies

Where it is necessary to distinguish between different technologies:

  • Vintage analog filter (active) and Class A / B amplifier
  • DSP-based filter (digital) and Class-D amplifier
DSP and Class D

Since the DSP based solutions made great progress and the integrated DAC's are getting better, we became interested in the topic more and more. The development of Class-D amplifiers and high-quality switching power supplies are extremely important for active speakers.

In winter 2010, we were able to introduce the passive version of this speaker. The active variant exists as prototypes and has already convinced some of our testers.
The development

We use the DSP-based filter for quite some time - e.g. when we evaluate and test with new chassis. These filters are developed extremely flexible and relatively fast, different polls can be compared very quickly. The total development can be so much more extensive and occur faster. It is very important for us to have our cutting edge measurement equipment.

The path from the evaluation board to a finished product is still far. In particular, the signaling pathway involved and the DAC's are a big issue.

FIR filter and time alignment

For developing our "custom-design" models, we started our investigations with DSP and a Class D technology. The products are quite expensive and complex. In addition, the project budgets are usually somewhat more extensive.

The possibility of equalization of very large loudspeakers and the use of class-d amps for the subwoofer made this technique even more interesting. Adjustments on site in the listening room can be easily implemented.

  • Chassis: 1 "dual ring radiator, 1 x 5.25" mid / woofer
  • Tuning: Bass Reflex (back)
  • Crossover: 2-way FIR
  • Frequency response: 40 Hz - 48 kHz, + / - 0.5dB
  • AC power supply: 100V - 250V
  • Amplifier Power: 2 x 375 watts
  • Max level (SPL) 114dB
  • Input Impedance: 10 Ohm Co (balanced)
  • Gain: 32dB
  • THD + N: <0.005% 0.1 - 375W
  • Weight: 19.5 kg per piece without packaging
  • Size (H x D x W): 90 cm x 22 cm x 18 cm
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