Monacor Cobra-Horn RBT floorstanding loudspeaker Kit with our high-end crossover

Kit with high-end crossover without housing price per speaker

Cobra-Horn RBT is a large floor-standing loudspeaker designed as a hyperbolic back-loaded horn. The horn is driven by the Monacor broadband SP-200X; in the upper frequency range, the Monacor magnetostat RBT-95 SR takes over playback. The kit was designed by Bernd Timmermanns. The crossover consists of a 2nd order low-pass filter (12 dB/octave) for the broadband loudspeaker and a 2nd order high-pass filter (12 dB/octave) for the magnetostat. The frequency response of the loudspeaker is quite linear. The decay spectrum is slightly delayed in the middle. The non-linear distortions are quite low at 90 dB/1m in the low and mid-range and increase to just under 3% from 2 kHz.

The high-end kit contains Mundorf MCAP EVO capacitors. The coils are designed as baked varnish air coils to reduce the microphonic effect (the current through the coil generates a magnetic field, which in turn sets the winding in motion. This movement induces voltages in the coil, which are added to the useful signal. The tighter the winding of the coil, the less the useful signal is distorted.)

Technical data:

• Impedance: 8 Ohm
• Sound pressure level (2.83V/1m): 93 dB
• Dimensions (HxWxD): 1078 x 338 x 500 mm
• Frequency range (-8dB): 50 - 30000 Hz
• Crossover frequency(s): 5000 Hz
• Principle: Horn

Highlights

• Magnetostat tweeter RBT-95SR
• Monacor SP-200 X broadband loudspeaker
• 0.5x PE foam sealing strip, 5x2 mm, roll 7.5 m
• 2.5x Sonofil insulation material 100 x 35 cm for 20 liters
• Pole terminals PK31, one pair, gold-plated, red+black
• 2m speaker cable 2x2.5 mm2, transparent
• Pan screws 4x20 black, Phillips, 8 pieces
• Construction plan for the kit the crossover components (right), to be assembled on a wooden board.
• Mundorf MCAP EVO 1.5 μF / 450 V
• Mundorf MCAP EVO oil 2.7 μF / 450 V
• Mundorf baked varnish air coil BL71, 0.15 mH/0.28 Ohm
• Mundorf baked varnish air coil BL140, 0.47 mH/0.19 Ohm
• MOX5 resistor 68 Ohm / 5 Watt (blue-gray-black)
• Metal oxide resistor MOX5 0.68 Ohm 5% (blue-gray-silver)
• Metal oxide resistor MOX5 4.7 Ohm (yellow-violet-gold)