Alcone Otra floorstanding speakers from K+T magazine 2/2019

Kit without housing, price per speaker

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Otra is a three-way floorstanding loudspeaker.

Otra is a bass reflex loudspeaker with chassis from Scan-Speak, SEAS and Alcone.

The loudspeaker contains the following loudspeaker chassis: - a Scan-Speak R2604/832000 tweeter - a SEAS L18RCY/P (H1085-08) midrange speaker - an Alcone AC10 HE woofer 

The crossover consists of:

- a 3rd order high pass (18 dB / octave) for the tweeter.

- a band pass consisting of a 2nd order high pass (12 dB / octave) and a 3rd order low pass (18 dB / octave) for the mid-bass loudspeaker.

- a 2nd order low pass (12 dB / octave) for the bass loudspeaker.

The frequency response of the loudspeaker is perfectly linear.

The decay spectrum (waterfall diagram) is exemplary without any disturbing resonance.

The non-linear distortions at low volumes (85 dB, 1 m) are below 0.4% above 300 Hz and remain below 0.7% in the audible range even at higher levels (95 dB, 1 m).

Technical data:

• impedance: 4 Ohm
• Sound pressure level (2.83V/1m): 85 dB
• Dimensions (HxWxD): 1000 x 220 x 350 mm
• Frequency range (-8dB): 28 - 38000 Hz
• Crossover frequency(s): 120, 1900 Hz
• Principle: bass reflex box

Highlights

• Seas L18RCY/P (W180 NAL, H1085-08)
• ScanSpeak ring radiator R2604/832000
• Alcone 25 cm loudspeaker AC10 HE, aluminum membrane
• Bass reflex tube HP70 XL, 70x220 mm, black
• Insulating fleece MT Bondum 800 (30 x 50 x 2 cm)
• 0.5x PE foam sealing strip, 5x2 mm, roll 7.5 m
• Insulating material Sonofil 100 x 35 cm for 20 liters
• 3m loudspeaker cable 2x1.5 mm2 black/red
• 2.5x pan screws 4x20 black, Phillips, 8 pieces
• Construction plan for the kit the crossover components (right), to be assembled on a wooden board.
• Audaphon MKP CAP Superior 3.3 μF / 400 Vdc
• Audaphon MKP CAP Superior 8.2 μF / 400 Vdc
• Audaphon MKT capacitor 2.2 μF / 160 Vdc
• Audaphon MKT capacitor 10 μF / 160 Vdc
• 2x Elko rough, 330 μF/63 Vdc
• Elko smooth, 56uF / 50 Vdc
• Elko smooth, 68uF / 50 Vdc
• Mundorf air coil L140, 0.47 mH/0.19 Ohm
• 1.4 mm air coil, 1.8 mH/0.41 Ohm
• 0.7 mm air coil, 0.33 mH/0.48 Ohm
• 0.7 mm air coil, 0.47 mH/0.50 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
• Ceramic resistor 3.3 Ohm/20 Watt
• Ceramic resistor 3.9 Ohm/20 Watt
• Metal oxide resistor MOX10 3.3 Ohm (orange-orange-gold)
• Metal oxide resistor MOX10 4.7 Ohm (yellow-violet-gold)

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