Isar   Shelf speaker as in K+T 5/2023

Technical data
  • impedance: 8 Ohm
  • sensivity (2,83V/1m): 85 dB
  • size (HxWxD): 430 x 220 x 320 mm
  • frequency range (-8dB): 36 - 30000 Hz
  • crossover frequency(s): 2400 Hz
  • speaker type: bass reflex
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Isar is a two way compact speaker.

Isar is a bass-reflex cabinet loudspeaker with drivers of Audaphon and Accuton.

The kit is delivered with the following drivers:
- a Audaphon AMT-1i rund air motion transformer (ribbon-tweeter)
- a Accuton C173-6-191 woofer

The loudspeaker has been developed by Dennis Frank and Daniel Gattig.

The crossover consists of:
- a 2nd order high-pass filter (12 dB per octave slope) for the tweeter.
- a first order low-pass filter (6 dB per octave slope) for the woofer.

The frequency response of this speaker is perfectly linear.

The decay spectrum is perfect.

At low volume, i.e. 85 dB at 1 m, the nonlinear distortions are below 0,9% above 300 Hz and doesn't exceed 1% at 95 dB at 1 m between 300 and 15000 Hz.

An excerpt from the Klang+Ton review (Translation of the author into English)

Conclusion of the magazine Klang+Ton:

Our kit consists of

  • Accuton C173-6-191 mids/woofer, one unit
  • Audaphon AMT-1i round Faceplate
  • Bass reflex tube HP70, 70x220m, black
  • 2x Damping fleece MT Bondum 800 (30 x 50 x 2 cm)
  • 0,5x Damping Sonofil 100 x 35 cm for 20 litres
  • Binding Post PK28 I Ni, nickel plated (one pair, red and black)
  • 2m Speaker cable 2x1.5 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.

  • ClarityCap PWA capacitor 0.82 μF / 400 Vdc
  • Audaphon MKP CAP Superior 2.7 μF / 400 Vdc
  • Audaphon MKP CAP Superior 4.7 μF / 400 Vdc
  • 1.4 mm air core coil 2.2 mH/0.48 Ohm
  • 0.7 mm air core coil, 0.68 mH/0.70 Ohm
  • 0.7 mm air core coil, 0.82 mH/0.89 Ohm
  • 2x Metal-oxide resistor, 10W 4.7 Ohm (yellow-violet-gold)
  • Metal-oxide resistor, 10W 8.2 Ohm (grey-red-gold)

Kit without cabinet, price per speaker   EUR 1221,00 excl. VAT: € 1026.05 / $ 1108.13

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 rund are of type polypropylen (MKP) Clarity-Cap CMR 630 V.

  • ClarityCap CMR capacitor 4.7 μF / 630 Vdc
  • ClarityCap PWA capacitor 2.7 μF / 400 Vdc
  • ClarityCap PX capacitor 0.82 μF / 250 Vdc
  • Mundorf baked varnish air core coil BL71, 0.68 mH/0.71 Ohm
  • Mundorf baked varnish air core coil BL71, 0.82 mH/0.89 Ohm
  • Mundorf baked varnish air core coil BL140, 2.2 mH/0.46 Ohm
  • MResist Supreme 8.2 Ohm / 20 Watt
  • 2x Mresist Classic 4,7 Ohm / 10 Watt

Kit with high-end-crossover without cabinet, price per speaker   EUR 1407,00 excl. VAT: € 1182.35 / $ 1276.94

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 22 μF / 160 Vdc
  • 0.7 mm air core coil, 1.0 mH/0.88 Ohm
  • ceramic resistor 12 Ohm/20 Watt

Price per impedance correction for one speaker, to be mounted on a small wooden board.     EUR 17,60 excl. VAT: € 14.79 / $ 15.97

universal PCB

If you prefer to mount the crossover components on a universal PCB instead on wood
PCB 150x115 mm, tin plated, price per unit:   EUR 4,70 excl. VAT: € 3.95 / $ 4.27
We recommend one board per kit (2 boards per speaker pair)

Measurements

measurmentsMeasurements on this speaker

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