Harwood-Cinema Sat AM24 small   Shelf speaker as in Hobby Hifi 3/2022

Technical data
  • impedance: 6 Ohm
  • sensivity (2,83V/1m): 84 dB
  • size (HxWxD): 295 x 180 x 210 mm
  • frequency range (-8dB): 60 - 30000 Hz
  • crossover frequency(s): 2300 Hz
  • speaker type: closed box

Harwood-Cinema Sat AM24 small is a two way compact speaker.

Harwood-Cinema Sat AM24 small is a closed-cabinet loudspeaker with drivers of Harwood .

The kit is delivered with the following drivers:
- a Harwood AM 24 air motion transformer (ribbon-tweeter)
- a Harwood TM 130/25F1 woofer

The loudspeaker has been developed by Bernd Timmermanns.

The crossover consists of:
- a 3rd order high-pass filter (18 dB per octave slope) for the tweeter.
- a 2nd order low-pass filter (12 dB per octave slope) for the woofer.

The frequency response of this speaker is nearly linear.

The decay spectrum as shown in the waterfall diagram is exemplary, free of any disturbing resonance.

At medium volume, i.e. 90 dB at 1 m, the nonlinear distortions are below 0,35% above 200 Hz.

Our kit consists of

  • Harwood Air Motion Transformer AM 24
  • Harwood TM 130/25F1
  • 0,5x Damping fleece MT Bondum 800 (30 x 50 x 2 cm)
  • 0,5x PE sealing tape, 5x2 mm, 7.5 m
  • 0,25x Damping Sonofil 100 x 35 cm for 20 litres
  • Binding Post PK31, gold plated (one pair, red and black)
  • 1,5m Speaker cable 2x1.5 mm2, transparent
  • 0,5x Pan screws 4x20 black, torx, 8 pieces
  • 0,5x Visaton Countersunk screws 3.5x25, 8 pcs
  • Plan for DIY kit

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

  • Audaphon MKP CAP Superior 2.2 μF / 400 Vdc
  • Audaphon MKP CAP Superior 5.6 μF / 400 Vdc
  • Audaphon MKT CAP 8.2 μF / 160 Vdc
  • Audaphon MKT CAP 10 μF / 160 Vdc
  • JB, electrolytic capacitor, bipolar advanced, 4.7 μF / 50 Vdc
  • JB, electrolytic capacitor, bipolar advanced, 22μF / 50 Vdc
  • Mundorf air core coil L50, 1.5 mH/1.85 0hm
  • 0.7 mm air core coil, 1.0 mH/0.88 Ohm
  • Audaphon M core coil M12, 1.5 mH/0.16 0hm
  • Metal-oxide resistor, 10W 8.2 Ohm (grey-red-gold)
  • Metal-oxide resistor, 10W 12 Ohm (brown-red-black)
  • Metal-oxide resistor, 5W 33 Ohm (orange-orange-black)

Kit without cabinet, price per speaker   - not available

Kit with high-end crossover

The high-end kit is delivered with baked varnish air core coils on important parts of the crossover 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 capacitors for the Harwood AM 24 are of type polypropylen (MKP) Mundorf MCAP EVO Öl 450 V.

  • Mundorf MCAP EVO Oil 2.2 μF / 450 V
  • Mundorf MCAP EVO Oil 5.6 μF / 450 V
  • Audaphon MKP CAP Superior 18 μF / 400 Vdc
  • JB, electrolytic capacitor, bipolar advanced, 4.7 μF / 50 Vdc
  • JB, electrolytic capacitor, bipolar advanced, 22μF / 50 Vdc
  • Mundorf baked varnish air core coil BL71, 1.0 mH/1.02 Ohm
  • Mundorf air core coil L50, 1.5 mH/1.85 0hm
  • Mundorf H core Hepta Coil LH45, 1,5 mH/0.16 Ohm
  • Metal-oxide resistor, 10W 8.2 Ohm (grey-red-gold)
  • Metal-oxide resistor, 10W 12 Ohm (brown-red-black)
  • Metal-oxide resistor, 5W 33 Ohm (orange-orange-black)

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

Additonal high pass filter 100 Hz

  • Mundorf, electrolytic capacitor, etched, 180 μF/63 Vdc
  • 0.7 mm air core coil, 4.7 mH/2.19 Ohm
  • Metal-oxide resistor, 5W 0.56 Ohm 5% (green-blue-silver)

Kit without cabinet, price per speaker   EUR 20,30 excl. VAT: € 17.06 / $ 18.59

Additonal high-end high pass filter 100 Hz

  • ClarityCap PWA capacitor 33 μF / 160 Vdc
  • Mundorf, electrolytic capacitor, etched, 150 μF/63 Vdc
  • Mundorf baked varnish air core coil BL71, 4.7 mH/2.19 Ohm
  • Metal-oxide resistor, 5W 0.56 Ohm 5% (green-blue-silver)

Additional filter-kit with high-end-crossover without cabinet, price per speaker   EUR 33,60 excl. VAT: € 28.24 / $ 30.78

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).

  • Audaphon MKT CAP 10 μF / 160 Vdc
  • Audaphon MKT CAP 33 μF / 160 Vdc
  • 0.7 mm air core coil, 0.47 mH/0.50 Ohm
  • ceramic resistor 6.8 Ohm/20 Watt
  • Metal-oxide resistor, 10W 6.8 Ohm (blue-grey-gold)

Price per impedance correction for one speaker, to be mounted on a small wooden board.     EUR 20,00 excl. VAT: € 16.81 / $ 18.32

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 / $ 3.85
We recommend one board per kit (two boards for a speaker pair)


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