Harwood-Cinema Center AM24   Home Cinema as in Hobby Hifi 2/2022

Technical data
  • impedance: 4 Ohm
  • sensivity (2,83V/1m): 89 dB
  • size (HxWxD): 180 x 440 x 260 mm
  • frequency range (-8dB): 60 - 27000 Hz
  • crossover frequency(s): 2300 Hz
  • speaker type: closed box

Harwood-Cinema Center AM24 is a two way compact speaker.

It is available as satellit or as center.

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

The kit is delivered with the following drivers:
- a Harwood AM24 air motion transformer (ribbon-tweeter)
- two Harwood TM 130/25F1 woofers

The loudspeaker has been developed by Bernd Timmermanns.

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

The frequency response of this speaker is nearly linear.

The decay spectrum is perfect.

At medium volume, i.e. 90 dB at 1 m, the nonlinear distortions are below 0,32% above 400 Hz.

Our kit consists of

  • Harwood Air Motion Transformer AM 24
  • 2x Harwood TM 130/25F1
  • 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
  • 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 3.9 μF / 400 Vdc
  • Audaphon MKP CAP Superior 10 μF / 400 Vdc
  • Audaphon MKP CAP Superior 22 μF / 400 Vdc
  • 1.4 mm air core coil, 1.0 mH/0.29 Ohm
  • 0.7 mm air core coil, 0.56 mH/0.55 Ohm
  • Metal-oxide resistor, 10W 2.2 Ohm (red-red-gold)

Kit without cabinet, price per speaker   - not available

Price for a pair of custom speakers of any color   - not available (_)

Kit with high-end crossover

The high-end kit is delivered with Hepta 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 AM24 are of type polypropylen (MKP) Clarity-Cap PWA 160.

  • Mundorf MCAP EVO Oil 3.9 μF / 450 V
  • Mundorf MCAP EVO Oil 10 μF / 450 V
  • Mundorf MCAP EVO Oil 22 μF / 450 V
  • Mundorf Hepta Coil II45, 0.56 mH/0.30 Ohm
  • Mundorf Hepta Coil II45, 1.0 mH/0.42 Ohm
  • Metal-oxide resistor, 10W 2.2 Ohm (red-red-gold)

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

Additonal GHP capacitor for 25 liter cabinet

JB Elko bipolar, 470 uF/50 Vdc   EUR 5,80 excl. VAT: € 4.87 / $ 5.17

Additonal high pass filter 100 Hz

  • JB, electrolytic capacitor, bipolar, 100 μF/100 Vdc
  • Mundorf H core coil H71, 5.6 mH/0.62 0hm

Kit without cabinet, price per speaker   EUR 17,10 excl. VAT: € 14.37 / $ 15.23

Additonal high-end high pass filter 100 Hz

  • ClarityCap PWA capacitor 100μF / 160 Vdc
  • Mundorf H core baked varnish coil BH71, 5.6 mH/0.62 0hm

Kit with high-end-crossover without cabinet, price per speaker   on request

Additonal high pass filter 140 Hz

  • JB, electrolytic capacitor, bipolar, 82 μF/100 Vdc
  • 1.0 mm air core coil, 4.7 mH/1.25 Ohm

Kit without cabinet, price per speaker   EUR 38,40 excl. VAT: € 32.27 / $ 34.21

Additonal high-end high pass filter 140 Hz

  • ClarityCap PWA capacitor 82 μF / 160 Vdc
  • Mundorf baked varnish air core coil BL100, 4.7 mH /1.25 Ohm

Kit with high-end-crossover without cabinet, price per speaker   EUR 65,40 excl. VAT: € 54.96 / $ 58.26

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).

  • JB, electrolytic capacitor, bipolar advanced, 33μF / 100 Vdc
  • 0.7 mm air core coil, 0.10 mH/0.27 Ohm
  • ceramic resistor 5.6 Ohm/20 Watt

Price per impedance correction for one speaker, to be mounted on a small wooden board.     EUR 9,70 excl. VAT: € 8.15 / $ 8.64

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 / $ 3.74
We recommend one board per kit (two boards for a speaker pair)


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