Radius   Shelf speaker as in K+T 4/2014

Technical data
  • impedance: 6 Ohm
  • sensivity (2,83V/1m): 84 dB
  • size (HxWxD): 380 x 200 x 220 mm
  • frequency range (-8dB): 45 - 32000 Hz
  • crossover frequency(s): 880, 3800 Hz
  • speaker type: bass reflex

Radius is a small 3-way-shelf-speaker. It is developed by Thomas Schmidt.

Radius is a bass reflex speaker with Morel drivers: a dome midrange Morel EM-1308, a Morel woofer EW-638 and a tweeter ET-448. It is a bassreflex loudspeaker.

The crossover consists of 2rd order filters (12 dB per octave slope).

The frequency response is quite flat, the harmonic distortion is low (less than 0.3% above 500Hz at 85 dB (1m)). The decay spectrum shows a small resonance at 500 Hz; apart from that it is without any fault.

An excerpt from the Klang+Ton review

"With the tweeters placed outwards and the loudspeakers aligned parallel to the side walls the end result is an impressively broad sweet spot, so that even three people can experience an almost identical frequency response on the couch. This is accompanied by a very stable and natural spatial representation that makes listening to music a real happening without straining the listener in any way. Even when placed free-standing, the pronounced upper bass of the Radius produces so much pressure that there is no desire for more bass. Close to the rear wall and at shorter listening distances, the closed version is the more honest version of the two. You can hear that these drivers are real experts in their dedicated ranges. The sum of the parts results in a really supreme loudspeaker that, when care is taken to position them correctly, will be able to reveal their full potential to a bigger audience."

Our kit consists of

  • Morel mids dome EM 1308
  • Morel tweeter ET 448
  • Morel woofer EW 638
  • Bass reflex tube BR50, 50x145 mm, black
  • PE sealing tape, 5x2 mm
  • Damping Sonofil 100 x 35 cm for 20 litres
  • Binding Post PK31, gold plated (one pair, red and black)
  • 2m Speaker cable 2x1.5 mm2, transparent
  • Pan screws 3.5x17 black, cross recess, 18 pieces
  • Plan for DIY kit

the crossover components (right),
to be mounted on a small wooden board.
  • Audaphon MKT CAP 8.2 uF / 160 Vdc
  • Audaphon MKT CAP 22 uF / 160 Vdc
  • Audaphon MKT CAP 33 uF / 160 Vdc
  • Audaphon MKP CAP Superior 2.2 uF / 400 Vdc
  • Audaphon MKP CAP Superior 10 uF / 400 Vdc
  • 0.7 mm air core coil, 0.22 mH/0.39 Ohm
  • 1.0 mm air core coil, 0.82 mH/0.44 Ohm
  • 1.0 mm air core coil, 1.2 mH/0.54 Ohm
  • 1.4 mm air core coil, 1.5 mH/0.38 Ohm
  • Metal-oxide resistor, 10W 5.6 Ohm (green-blue-gold)
  • Metal-oxide resistor, 10W 8.2 Ohm (grey-red-gold)
  • Metal-oxide resistor, 10W 10 Ohm (brown-black-black)


Kit without cabinet,
price per speaker   - not available

Kit with high-end crossover

Our high-end version employs Mundorf copper foil coils or ClarityCap capacitors of type MR in series to the loudspeakers. Elsewhere baked varnish air core coils or ClarityCap PWA capacitors are used.


Kit without cabinet,
price per speaker   - not available

Kit with Mundorf high-end crossover #2

Our high-end version employs Mundorf copper foil coils or Mundorf EVO Silver Gold Oil capacitors in series to the loudspeakers. Elsewhere baked varnish air core coils or Mundorf EVO capacitors are used.


Kit without cabinet,
price per speaker   - not available

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 / $ 4.93
We recommend two boards per kit (four boards for a speaker pair)


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