MoMo 175RBT   Floorstanding as in Hobby Hifi 4/2015

Technical data
  • impedance: 8 Ohm
  • sensivity (2,83V/1m): 85 dB
  • size (HxWxD): 1053 x 225 x 345 mm
  • frequency range (-8dB): 25 - 40000 Hz
  • crossover frequency(s): 3200 Hz
  • speaker type: bass reflex

MoMo 175RBT is a bassreflex floorstanding speaker with high quality woofer of Monacor and a ribbon tweeter with waveguide. The kit is delivered with woofer Monacor SPH 175HQ and ribbon tweeter Monacor RBT-35SR. The floorstander has been developed by Bernd Timmermanns.

The crossover consists of a 3rd order high-pass filter (18 dB per octave slope) for the tweeter. The woofer is connected to a 6nd order low-pass filter.

Between 60 Hz and 25000 Hz, the frequency response of the loudspeaker is very linear on axis. The decay spectrum is without fault. At low volume, i.e. 90 dB at 1 m, the nonlinear distortions are lower than 0,5% above 200 Hz.

Our kit consists of

  • Monacor ribbon tweeter RBT-35SR
  • Monacor woofer SPH-175HQ
  • 2x Bass reflex tube HP70, 68x160 mm, black
  • PE sealing tape, 5x2 mm
  • 1,5x Damping Sonofil 100 x 35 cm for 20 litres
  • Binding Post PK28 I, gold plated (one pair, red and black)
  • 3m Speaker cable 2x2.5 mm2, transparent
  • 1,5x Pan screws 4x20 black, cross recess, 8 pieces
  • Plan for DIY kit

the crossover components (right),
to be mounted on a small wooden board.
  • Mundorf MCAP EVO 0.68 μF / 450 V
  • Mundorf MCAP EVO 1 μF / 450 V
  • Mundorf MCAP EVO 2.7 μF / 450 V
  • Audaphon MKP CAP Superior 0.68 μF / 400 Vdc
  • Mundorf air core coil L50, 1 mH/1.47 0hm
  • Mundorf air core coil L140, 1.8 mH/0.43 Ohm
  • 0.7 mm air core coil, 0.10 mH/0.27 Ohm
  • 0.7 mm air core coil, 0.47 mH/0.50 Ohm
  • Metal-oxide resistor, 10W 6.8 Ohm (blue-grey-gold)
  • Metal-oxide resistor, 5W 2.2 Ohm (red-red-gold)
  • Metal-oxide resistor, 5W 12 Ohm (brown-red-black)
  • Metal-oxide resistor, 5W 15 Ohm (brown-green-black)

Kit without cabinet, price per speaker   EUR 358,00 excl. VAT: € 300.84 / $ 315.88

Kit with high-end crossover

The high-end kit comes with an copper foil coil instaed of an air core coil for the woofer. In the filter for the tweeter the capacitors are Evo/oil capacitors. Most 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 speaker   EUR 425,00 excl. VAT: € 357.14 / $ 375.00

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 16,10 excl. VAT: € 13.53 / $ 14.21

universal PCB

If you prefer to mount the crossover components on a 140 x 102 mm universal PCB instead on wood:
Universal PCB RA140, order no.. str-RA140, price per unit:   EUR 4,20 excl. VAT: € 3.53 / $ 3.71

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