Audimax Micro AMT   Shelf speaker as in Hobby Hifi 6/2022

Technical data
  • impedance: 8 Ohm
  • sensivity (2,83V/1m): 79 dB
  • size (HxWxD): 335 x 200 x 300 mm
  • frequency range (-8dB): 38 - 36000 Hz
  • crossover frequency(s): 2500 Hz
  • speaker type: closed box

Audimax Micro AMT is a two way compact speaker.

Audimax Micro AMT is a closed-cabinet loudspeaker with drivers of Mundorf and SEAS.

The kit is delivered with the following drivers:
- a Mundorf AMTU60W1.1-C air motion transformer (ribbon-tweeter)
- a Hobby-HiFi 18MW12T (von SEAS produziert) 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 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 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 0,33% above 200 Hz.

Our kit consists of

  • Mundorf AMTU60W1.1-C
  • Hobby-HiFi woofer 18MW12T, produced by SEAS
  • 0,5x Damping fleece MT Bondum 800 (30 x 50 x 2 cm)
  • 0,5x PE sealing tape, 5x2 mm, 7.5 m
  • 0,5x Audaphon Damping 10, 970 x 470 mm, adhesive
  • Binding Post PK31, gold plated (one pair, red and black)
  • 1,5m Speaker cable 2x2.5 mm2, transparent
  • Pan screws 4x20 black, torx, 8 pieces
  • Visaton Countersunk screws 3.5x25, 8 pcs
  • Plan for DIY kit

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

  • Mundorf MCAP EVO Oil 0.47 μF / 450 V
  • Mundorf MCAP EVO Oil 0.68 μF / 450 V
  • 2x Mundorf MCAP EVO Oil 3.3 μF / 450 V
  • 2x Mundorf MCAP EVO Oil 3.9 μF / 450 V
  • Mundorf MCAP EVO Oil 6.8 μF / 450 V
  • Mundorf MCAP EVO Oil 10 μF / 450 V
  • JB, electrolytic capacitor, bipolar, 100 μF/100 Vdc
  • JB, electrolytic capacitor, bipolar, 220 μF/100 Vdc
  • Mundorf air core coil L140, 0.82 mH/0.26 Ohm
  • Mundorf air core coil L140, 3.9 mH/0.65 Ohm
  • 0.7 mm air core coil, 0.33 mH/0.48 Ohm
  • 0.7 mm air core coil, 0.39 mH/0.51 Ohm
  • 0.7 mm air core coil, 1.2 mH/1.08 Ohm
  • 0.7 mm air core coil, 8.2 mH/3.05 Ohm
  • 0.7 mm air core coil, 15 mH/4,45 Ohm
  • Metal-oxide resistor, 10W 5.6 Ohm (green-blue-gold)
  • Metal-oxide resistor, 10W 10 Ohm (brown-black-black)
  • Metal-oxide resistor, 5W 1.0 Ohm (brown-black-gold)
  • Metal-oxide resistor, 5W 2.2 Ohm (red-red-gold)
  • 2x Metal-oxide resistor, 5W 10 Ohm (brown-black-black)
  • Metal-oxide resistor, 5W 33 Ohm (orange-orange-black)

Kit without cabinet, price per speaker   EUR 1101,00 excl. VAT: € 925.21 / $ 971.47

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 Mundorf AMTU60W1.1-C are of type polypropylen (MKP) Mundorf MCAP EVO Silber Gold Öl 450 V.

  • Mundorf MCAP EVO Oil 0.47 μF / 450 V
  • 2x Mundorf MCAP EVO Oil 3.3 μF / 450 V
  • Mundorf MCAP EVO Oil 3.9 μF / 450 V
  • Mundorf MCAP EVO Oil 10 μF / 450 V
  • Mundorf MCAP EVO Silver Gold Öl 0.68 μF / 450 V
  • Mundorf MCAP EVO Silver Gold Öl 3.9 μF / 450 V
  • Mundorf MCAP EVO Silver Gold Öl 6.8 μF / 450 V
  • JB, electrolytic capacitor, bipolar, 100 μF/100 Vdc
  • JB, electrolytic capacitor, bipolar, 220 μF/100 Vdc
  • Mundorf copper foil coil CFC14-0.82 mH/0.22Ohm
  • Mundorf copper foil coil CFC14-3.9 mH/0.53Ohm
  • Mundorf baked varnish air core coil BL71, 0.33 mH/0.48 Ohm
  • Mundorf baked varnish air core coil BL71, 0.39 mH/0.51 Ohm
  • Mundorf baked varnish air core coil BL71, 1.2 mH/1.08 Ohm
  • Mundorf baked varnish air core coil BL71, 8.2 mH/3.05 Ohm
  • Mundorf baked varnish air core coil BL71, 15 mH/4.45 Ohm
  • MResist Supreme 5.6 Ohm / 20 Watt
  • MResist Supreme 10 Ohm / 20 Watt
  • Metal-oxide resistor, 5W 1.0 Ohm (brown-black-gold)
  • Metal-oxide resistor, 5W 2.2 Ohm (red-red-gold)
  • 2x Metal-oxide resistor, 5W 10 Ohm (brown-black-black)
  • Metal-oxide resistor, 5W 33 Ohm (orange-orange-black)

Kit with high-end-crossover without cabinet, price per speaker   EUR 1367,00 excl. VAT: € 1148.74 / $ 1206.18

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).

  • Mundorf MCAP EVO Oil 1 μF / 450 V
  • JB, electrolytic capacitor, bipolar, 47 μF/100 Vdc
  • 0.7 mm air core coil, 0.10 mH/0.27 Ohm
  • 0.7 mm air core coil, 0.47 mH/0.50 Ohm
  • ceramic resistor 8.2 Ohm/20 Watt
  • Metal-oxide resistor, 10W 22 Ohm (red-red-black)

Price per impedance correction for one speaker, to be mounted on a small wooden board.     EUR 28,50 excl. VAT: € 23.95 / $ 25.15

universal PCB

If you prefer to mount the crossover components on a 240 x 165 mm universal PCB instead on wood:
Universal PCB RA240, order no.. str-RA240, price per unit:   EUR 8,60 excl. VAT: € 7.23 / $ 7.59
We recommend one board per kit (two boards for a speaker pair)


Home   Hobby HiFi Overview