Micro Block   Shelf speaker as in Hobby Hifi 2/2015

Technical data
  • impedance: 6 Ohm
  • sensivity (2,83V/1m): 82 dB
  • size (HxWxD): 350 x 150 x 310 mm
  • frequency range (-8dB): 40 - 34000 Hz
  • crossover frequency(s): 1200 Hz
  • speaker type: bass reflex

The Micro-Block is a compact loudspeaker with extremely well-behaved sound dispersion and other very good sonic properties at a low price. Bernd Timmermanns has developed this bass reflex speaker. The Micro-Block is home to a Wavecor dome, the TW030WA12, and the subwoofer SW118WA02.

We warmly recommend this loudspeaker.

Its crossover consists of a low-pass and a high-pass branch each of second order, i.e. with a slope of 18 dB per octave. A resistor sits in series to the tweeter as a voltage divider. To give a slight lifting to the highest treble, a capacitor is wired parallel to that resistor. No components were needed for eliminating any resonances or bulges in the frequency response.

We see a very even on-axis frequency response from 30 Hz to 30,000 Hz. The decay spectrum (waterfall diagram over frequency) is exemplary, free of any disturbing resonance. At 90 dB and 1 m, non-linear distortions remain below 0.4 % almost everywhere above 200 Hz.

An excerpt from the Hobby HiFi review

Conclusion of the magazine Hobby HiFi:

Our kit consists of

  • Wavecor silk dome tweeter TW030WA12, 8 Ohm
  • Wavecor Subwoofer SW118WA02, 8 Ohm
  • Bass reflex tube HP50, 50x145 mm, black
  • Damping fleece MT Bondum 800 (30 x 50 x 2 cm)
  • Binding Post PK31, gold plated (one pair, red and black)
  • 2m Speaker cable 2x2.5 mm2, transparent
  • Pan screws 4x20 black, cross recess, 8 pieces
  • Plan for DIY kit

the crossover components (right),
to be mounted on a piece of wood
  • Mundorf MCAP EVO Oil 6.8 uF / 450 V
  • ClarityCap PWA capacitor 33 uF / 160 Vdc
  • Audaphon MKP CAP Superior 1.0 uF / 400 Vdc
  • Mundorf baked varnish air core coil BL71, 1.5 mH/0.96 Ohm
  • Mundorf baked varnish air core coil BL140, 2.2 mH/0.46 Ohm
  • Metal-oxide resistor, 5W 6.8 Ohm (blue-grey-gold)
  • Metal-oxide resistor, 10W 8.2 Ohm (grey-red-gold)

Kit without cabinet, price per speaker   EUR 218,00 excl. VAT: € 183.19 / $ 212.50

Kit with high-end crossover

The high-end kit contains Mundorf MCAP EVO capacitors of which 2 are Silver Gold Oil capacitors. The coils are a Mundorf Hepta coil and a baked varnish coil for diminishing the microphonics effect. Current flowing through the coil creates a magnetic field which on itself sets the reel of wire in motion. That motion induces a voltage in the coil which adds itself to the original signal.

  • Mundorf MCAP EVO Silver Gold Öl 1 uF / 450 V
  • Mundorf MCAP EVO Silver Gold Öl 6.8 uF / 450 V
  • Mundorf MCAP EVO Oil 33 uF / 450 V
  • Mundorf baked varnish air core coil BL71, 1.5 mH/0.96 Ohm
  • Mundorf Hepta Coil II60, 2.2 mH/0.47 Ohm
  • Metal-oxide resistor, 5W 6.8 Ohm (blue-grey-gold)
  • Metal-oxide resistor, 10W 8.2 Ohm (grey-red-gold)

Kit with high-end-crossover without cabinet, price per speaker   EUR 339,00 excl. VAT: € 284.87 / $ 330.45

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 33,00 excl. VAT: € 27.73 / $ 32.17

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 / $ 4.97
We recommend one board per kit (two boards for a speaker pair)


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