CT 289 (BlueStart 3.5 FAST)   Floorstanding as in K+T 1/2017

Technical data
  • impedance: 4 Ohm
  • sensivity (2,83V/1m): 82 dB
  • size (HxWxD): 950 x 138 x 238 mm
  • frequency range (-8dB): 50 - 21000 Hz
  • crossover frequency(s): Hz
  • speaker type: bass reflex
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The CT 289 (BlueStart 3.5 FAST) is a FAST (Fullrange and Subwoofer Technology) speaker with drivers from Omnes Audio and LPG. The kit is delivered with the Omnes Audio BB 3.5 as fullrange driver and the LPG 13 for the bass range.

CT 289 (BlueStart 3.5 FAST) is developed by Thorsten Fischer.

The crossover consists of a 2nd order low-pass filter (12 dB per octave slope) for the woofer. The fullrange driver is connected to a 12 dB high-pass filter in series to a serial resistor.

The frequency response of this speaker is nearly linear on axis (with typical resonances of fullrange speakers) and with a slight sink at 300 Hz. The decay spectrum is without faults. At low volume, i.e. 85 dB at 1 m, the nonlinear distortions are mostly lower than 0.5 % above 400 Hz and stays below 2 % at 95 dB at 1 m .

Our kit consists of

  • full range Omnes Audio, BB 3.5
  • woofer LPG 13
  • Bass reflex tube BR50, 50x145 mm, black
  • 0,5x PE sealing tape, 5x2 mm, 7.5 m
  • 1,5x Damping Sonofil 100 x 35 cm for 20 litres
  • Terminal T105 Au, with brass, gold plated
  • 2m Speaker cable 2x1.5 mm2, transparent
  • Pan screws 3.5x17 black, cross recess, 8 pieces
  • 0,5x Pan screws 4x20 black, cross recess, 8 pieces
  • Plan for DIY kit

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

  • electrolytic capacitor, unetched, 33uF / 70 Vdc
  • electrolytic capacitor, unetched, 82uF / 50 Vdc
  • 1.0 mm air core coil, 1.8 mH/0.7 Ohm
  • 0.7 mm air core coil, 1.0 mH/1.02 Ohm
  • Metal-oxide resistor, 10W 2.7 Ohm (red-purple-gold)

Kit without cabinet, price per speaker   - not available

Kit with high-end crossover

The high-end kit is delivered complete with backlack 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. The capacitor in series to the fullrange driver are high quality polypropylen (MKP).

Kit with high-end-crossover without cabinet, price per speaker   - not available

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.. str-RA140, price per unit:   EUR 4,20 excl. VAT: € 3.53 / $ 3.85
We recommend one board per kit (two boards for a speaker pair)


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