Twerc   Floorstanding as in K+T 1/2016

Technical data
  • impedance: 4 Ohm
  • sensivity (2,83V/1m): 86 dB
  • size (HxWxD): 919 x 135 x 259 mm
  • frequency range (-8dB): 45 - 30000 Hz
  • crossover frequency(s): Hz
  • speaker type: bass reflex

Twerc is an two way floorstanding speaker with drivers of high quality from Wavecor. The kit is delivered with Wavecor TW022WA04 tweeter. The woofers are the Wavecor WF120BD04 with balance-drive technology (BD) and fibre glass cone.

Twerc has been developed by Wolfgang Grasshoff, Lautsprecher-Berlin.

The crossover consists of a 2nd order high-pass filter (12 dB per octave slope) for the tweeter. The woofers are connected to a 2 nd order low-pass filter (12 dB per octave slope).

The frequency response of this speaker is nearly linear; Wolfgang Grasshoff choose a drop of acoustic pressure in the presence range. The decay spectrum is nearly perfect. At low volume, i.e. 85 dB at 1 m, the nonlinear distortions are mostly lower than 0,5% above 300 Hz.

Our kit consists of

  • Wavecor silk dome tweeter TW022WA04, 4 Ohm
  • 2x Wavecor Mid/Woofer WF120BD10 glass fiber, die cast, 8 Ohm
  • Bass reflex tube HP50, 50x145 mm, black
  • PE sealing tape, 5x2 mm, 7.5 m
  • Damping Sonofil 100 x 35 cm for 20 litres
  • Binding Post PK31, gold plated (one pair, red and black)
  • 3m Speaker cable 2x1.5 mm2, transparent
  • 1,5x Pan screws 3.5x17 black, cross recess, 8 pieces
  • Plan for DIY kit

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

  • Mundorf MCAP EVO 6.8 uF / 450 V
  • Mundorf MKP capacitor 10 uF / 250 V
  • 1.0 mm air core coil, 0.68 mH/0.39 Ohm
  • 0.7 mm air core coil, 0.47 mH/0.50 Ohm
  • Metal-oxide resistor, 10W 1.0 Ohm (brown-black-gold)
  • 2x Metal-oxide resistor, 10W 2.2 Ohm (red-red-gold)

Kit without cabinet, price per speaker   EUR 290,00 excl. VAT: € 243.70 / $ 275.38

Kit with high-end crossover

The high-end kit is delivered with baked varnish air 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. All capacitors are MKP capacitors (polypropylen); in series to the tweeter a ClarityCap type ESA is applied.

Kit with high-end-crossover without cabinet, price per speaker   EUR 311,00 excl. VAT: € 261.34 / $ 295.32

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 12,50 excl. VAT: € 10.50 / $ 11.87

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 / $ 3.51
We recommend one board per kit (two boards for a speaker pair)


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