Cumulus Tower   Floorstanding as in Hobby Hifi 2/2018

Technical data
  • impedance: 6 Ohm
  • sensivity (2,83V/1m): 83 dB
  • size (HxWxD): 900 x 268 x 268 mm
  • frequency range (-8dB): 27 - 35000 Hz
  • crossover frequency(s): 500, 3500 Hz
  • speaker type: bass reflex

Cumulus Tower is a three way floorstanding speaker.

Cumulus Tower is a bass-reflex cabinet loudspeaker with drivers of Omnes Audio .

The kit is delivered with the following drivers:
- an Omnes Audio CX 3.1 coaxial driver
- an Omnes Audio W8 Alu, silver woofer

The loudspeaker has been developed by Nick Baur and Bernd Timmermanns.

The crossover consists of:
- a 3rd order high-pass filter (18 dB per octave slope) for the tweeter.
- a band pass consisting of a 2nd order high pass filter (12 dB per octave slope) and a 2nd order low-pass filter (12 dB per octave slope) for the mids-woofer.
- a 2nd order low-pass filter (12 dB per octave slope) for the woofer.

The frequency response of this speaker is nearly linear.

The decay spectrum as shown in the waterfall diagram is exemplary, free of any disturbing resonance.

At medium volume, i.e. 90 dB at 1 m, the nonlinear distortions are below 0.4% above 200 Hz.

Our kit consists of

  • Omnes Audio, coax driver CX 3.0/3.1
  • Omnes Audio woofer W8 Alu, silver
  • Bass reflex tube HP70, 68x160 mm, black
  • 1.5x Damping Sonofil 100 x 35 cm for 20 litres
  • Binding Post PK31, gold plated (one pair, red and black)
  • 3m Speaker cable 2x2.5 mm2, transparent
  • Plan for DIY kit

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

  • Audaphon MKP CAP Superior 2.2 uF / 400 Vdc
  • Audaphon MKP CAP Superior 6.8 uF / 400 Vdc
  • Mundorf, electrolytic capacitor, unetched, 6.8 uF / 70 Vdc
  • Mundorf, electrolytic capacitor, unetched, 33uF / 70 Vdc
  • Mundorf, electrolytic capacitor, unetched, 82uF / 50 Vdc
  • Mundorf baked varnish air core coil BL71, 0.22 mH/0.34 Ohm
  • Mundorf baked varnish air core coil BL71, 0.68 mH/0.71 Ohm
  • Mundorf baked varnish air core coil BL71, 3.3 mH/1.75 Ohm
  • Audaphon M core coil M14, 4.7 mH/0.24 0hm
  • MOX5-resistor 0.47 Ohm/5 Watt (yellow-violet-silver)
  • MOX5-resistor 2.2 Ohm/5 Watt (red-red-gold)
  • MOX5-resistor 33 Ohm/5 Watt (orange-orange-black)
  • Metal-oxide resistor, 10W 4.7 Ohm (yellow-violet-gold)
  • Metal-oxide resistor, 10W 10 Ohm (brown-black-black)

Kit without cabinet, price per speaker   EUR 230,00 excl. VAT: € 193.28 / $ 218.40

Kit with high-end crossover

The high-end kit is delivered with baked varnish air core coils on important parts of the crossover 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. The capacitors for the coaxial driver are of type polypropylen (MKP) Clarity-Cap PWA et Claity Cap ESA.

Kit with high-end-crossover without cabinet, price per speaker   EUR 260,00 excl. VAT: € 218.49 / $ 246.89

Impedance correction

If you want to use a valve amplifier with this speaker an impedance correction should be employed. In this case the component quality is less important; therefore, we offer only one kit (upon request higher quality components are available).


Price per impedance correction for one speaker, to be mounted on a small wooden board.     EUR 24,81 excl. VAT: € 20.85 / $ 23.56

universal PCB

If you prefer to mount the crossover components on a 159 x 127 mm universal PCB instead on wood:
Universal PCB RA160, order no.. I-2766, price per unit:   EUR 5,10 excl. VAT: € 4.29 / $ 4.84
We recommend one board per kit (two boards for a speaker pair)


Home   Hobby HiFi Overview