Cumulus BS 2017   Shelf speaker as in Hobby Hifi 1/2017

Technical data
  • impedance: 6 Ohm
  • sensivity (2,83V/1m): 87 dB
  • size (HxWxD): 400 x 240 x 320 mm
  • frequency range (-8dB): 40 - 22000 Hz
  • crossover frequency(s): 280, 3300 Hz
  • speaker type: bass reflex

Cumulus BS 2017 is a compact loudspeaker with coaxial loudspeaker and integrated subwoofer. Cumulus BS 2017 employs an Omnes Audio Exclusive 6 woofer and a Omnes Audio CX 3.1 coaxial driver. A digital signal processor corrects the frequency response. The power amplifiers for the different channels are not included in this kit.

Cumulus BS 2017 has been developed by Bernd Timmermanns.

The speaker is built in bassreflex technology.

The passive crossover is for the coaxial loudspeaker. It consists of a 3rd order high-pass filter (18 dB per octave slope) for the tweeter. The mids is connected to a 2nd order low-pass filter (12 dB per octave slope). The Mini-DSP 2x4 is used for the crossover between the coaxial loudspeaker and the woofer and equalizing the system for a perfect linearity. In addition a dual channel amplifier is needed for each loudspeaker.

Between 50 Hz and 20 kHz, the frequency response of this loudspeaker is perfect linear on 30 degrees measurement. On Axis the frequency response has two small bricks. The decay spectrum is without fault. At low volume, i.e. 90 dB at 1 m, the nonlinear distortions are below 0.4% above 200 Hz.

Our kit consists of

  • 2x Omnes Audio, coax driver CX 3.0/3.1
  • 2x Omnes Audio Exclusive 6
  • miniDSP 2x4
  • 3x Damping fleece MT Bondum 800 (30 x 50 x 2 cm)
  • PE sealing tape, 5x2 mm, 7.5 m
  • 4x Binding Post PK31, gold plated (one pair, red and black)
  • 4m Speaker cable 2x2.5 mm2, transparent
  • 3x Pan screws 4x20 black, cross recess, 8 pieces
  • Plan for DIY kit

the crossover components (right),
to be mounted on a small wooden board.

  • 2x Audaphon MKP CAP Superior 2.7 uF / 400 Vdc
  • 2x Audaphon MKP CAP Superior 6.8 uF / 400 Vdc
  • 2x Audaphon MKP CAP Superior 10 uF / 400 Vdc
  • 2x 1.0 mm air core coil, 1.0 mH/0.49 Ohm
  • 2x 0.7 mm air core coil, 0.22 mH/0.39 Ohm

Kit without cabinet, price per pair   EUR 678,00 excl. VAT: € 569.75 / $ 655.21

Kit with high-end crossover

The high-end kit comes with Mundorf EVO Oil capacitors. All inductances are baked varnished coils for minimizing microphonic effects. - The current flow through the coil creates a magnetic field which sets the reel of wire in motion. This motion induces a voltage in the coil which adds itself to the signal. The stiffer the reel of wire is, the less the signal will be altered.

Kit with high-end-crossover without cabinet, price per pair  EUR 748,00 excl. VAT: € 628.57 / $ 722.86

universal PCBs

If you prefer to mount the crossover components on a 140 x 102 mm universal PCB instead on wood:
Universal PCB RA140, order no.. I-2765, price per unit:   EUR 3,70 excl. VAT: € 3.11 / $ 3.58
We recommend two boards per kit


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