ViPA-AMT   Floorstanding as in Hobby Hifi 2-3/2024

Technical data
  • impedance: 4 Ohm
  • sensivity (2,83V/1m): 92,5 dB
  • size (HxWxD): 1360 x 470 x 400 mm
  • frequency range (-8dB): 40 - 28000 Hz
  • crossover frequency(s): 170, 2000 Hz
  • speaker type: bass reflex

ViPA-AMT is a three way floorstanding speaker.

ViPA-AMT is a bass-reflex cabinet loudspeaker with drivers of Audaphon and Visaton.

The kit is delivered with the following drivers:
- a Audaphon AMT 1i air motion transformer (ribbon-tweeter)
- a Visaton PAW 25 mids driver
- a Visaton PAW 38 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 band pass consisting of a 2nd order high pass filter (12 dB per octave slope) and a 3rd order low-pass filter (18 dB per octave slope) for the mids-woofer.
- 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 is perfect.

At medium volume, i.e. 90 dB at 1 m, the nonlinear distortions are below 0,5% above 100 Hz.

An excerpt from the Hobby HiFi review

Conclusion of the magazine Hobby HiFi:

Our kit consists of

  • Audaphon AMT-1i round Faceplate
  • Visaton woofer PAW 25, 8 Ohm
  • Visaton woofer PAW 38, 8 Ohm
  • 4,5x Damping fleece MT Bondum 800 (30 x 50 x 2 cm)
  • PE sealing tape, 5x2 mm, 7.5 m
  • 3x Damping Sonofil 100 x 35 cm for 20 litres
  • Binding Post PK28 I, gold plated (one pair, red and black)
  • 3m Speaker cable 2x2.5 mm2, transparent
  • 8x Allen screws M6x40 black, 1 pieces, (IS640)
  • 8x 1 pieces drive-in nuts M6, DIN 6930 g zinc-plated
  • Allen wood screws, black, 4x25 mm, 8 pieces
  • Plan for DIY kit

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

  • Audaphon MKP CAP Superior 5.6 μF / 400 Vdc
  • Audaphon MKP CAP Superior 6.8 μF / 400 Vdc
  • Audaphon MKP CAP Superior 10 μF / 400 Vdc
  • Audaphon MKP CAP Superior 22 μF / 400 Vdc
  • Audaphon MKT CAP 22 μF / 160 Vdc
  • Audaphon MKT CAP 33 μF / 160 Vdc
  • 2x Audaphon MKT CAP 100 μF / 160 Vdc
  • JB, electrolytic capacitor, bipolar, 220 μF/50 Vdc
  • 1.0 mm air core coil, 0.33 mH/0.26 Ohm
  • 1.0 mm air core coil, 0.68 mH/0.39 Ohm
  • 1.0 mm air core coil, 1.0 mH/0.49 Ohm
  • Mundorf bs140 core coil 15mH/0.48Ohm
  • Mundorf H core coil H71, 4.7 mH/0.46 0hm
  • Mundorf H core coil H71, 22 mH/1.49 0hm
  • Metal-oxide resistor, 10W 0.47 Ohm 5% (yellow-purple-silver)
  • 2x Metal-oxide resistor, 10W 2.2 Ohm (red-red-gold)
  • Metal-oxide resistor, 10W 5.6 Ohm (green-blue-gold)
  • Metal-oxide resistor, 10W 6.8 Ohm (blue-grey-gold)

Kit without cabinet, price per speaker   EUR 1378,00 excl. VAT: € 1157.98 / $ 1250.62

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 Audaphon AMT 1i are of type polypropylen (MKP) Mundorf MCAP-Supreme 600 V.

  • Mundorf MCAP Supreme 5.60 μF / 600 V
  • Mundorf MCAP Supreme 10 μF / 600 V
  • Audaphon MKP CAP Superior 6.8 μF / 400 Vdc
  • Audaphon MKP CAP Superior 22 μF / 400 Vdc
  • Audaphon MKT CAP 22 μF / 160 Vdc
  • Audaphon MKT CAP 33 μF / 160 Vdc
  • 2x Audaphon MKT CAP 100 μF / 160 Vdc
  • Mundorf, electrolytic capacitor, etched, 220 μF/63 Vdc
  • Mundorf Hepta Coil II45, 0.68 mH/0.34 Ohm
  • Mundorf baked varnish air core coil BL71, 4.7 mH/2.19 Ohm
  • Mundorf baked varnish air core coil BL71, 22 mH/5.66 Ohm
  • Mundorf baked varnish air core coil BL100, 0.33 mH/0.26 Ohm
  • Mundorf baked varnish air core coil BL100, 1.0 mH/0.49 Ohm
  • Mundorf bs180 core coil 15 mH/0.3 Ohm
  • MResist Supreme 2.2 Ohm / 20 Watt
  • Metal-oxide resistor, 10W 0.47 Ohm 5% (yellow-purple-silver)
  • Metal-oxide resistor, 10W 2.2 Ohm (red-red-gold)
  • Metal-oxide resistor, 10W 6.8 Ohm (blue-grey-gold)
  • Metal-oxide resistor, 5W 0.47 Ohm 5% (yellow-purple-silver)

Kit with high-end-crossover without cabinet, price per speaker   EUR 1570,00 excl. VAT: € 1319.33 / $ 1424.87

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 MKP CAP Superior 4.7 μF / 400 Vdc
  • 0.7 mm air core coil, 0.22 mH/0.34 Ohm
  • ceramic resistor 15 Ohm/20 Watt

Price per impedance correction for one speaker, to be mounted on a small wooden board.     EUR 10,20 excl. VAT: € 8.57 / $ 9.26

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 / $ 7.81
We recommend one board per kit (two boards for a speaker pair)


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