Helix Ci7 T20FM-SC

Helix Ci7 T20FM-SC – 20 mm High-End Silk Dome Tweeter with Coupling Volume

The Ci7 T20FM-SC is a 0.75″ (20 mm) high-end tweeter belonging to the HELIX COMPOSE platform, which re-engineers universal speakers so they combine universal flexibility with vehicle-specific advantages – “developed inside the vehicle, for the vehicle”. The i7 series is the high-end line of COMPOSE, made in Germany and clearly influenced by the sister brand BRAX; its impedances are matched to HELIX and MATCH amplifiers. The tweeter is intended as the treble driver of a high-quality component system and is designed to be installed in the vehicle’s original tweeter location.

Its fine-mesh silk dome is coated on both sides with a viscoelastic Acronal coating, and a dampened coupling volume filled with pure lamb’s wool behind the dome gives a very low resonance frequency and allows deep acoustic coupling. A neodymium magnet provides linear magnetic flux, the housing is turned from solid aluminum, and the tweeter is prepared for car-specific FlexMount20 adaptor rings and WireKits.

Key Features

• Super-wide dispersion: 20 mm silk dome combined with a coupling volume for wide sound dispersion and a low resonance frequency.
• Lightweight silk dome: fine-mesh dome with viscoelastic Acronal coating on both sides for smooth, detailed treble.
• Dampened coupling volume: damped with pure lamb’s wool; lowers the resonance (Fs 950 Hz) and allows a low crossover frequency.
• Neodymium magnet: provides linear magnetic flux.
• Solid aluminum housing: sturdy housing turned from solid aluminum.
• Compact design: small dimensions with several mounting options.
• Mounting hardware included: flush-mount rings and tweeter pods for surface/angled mounting are supplied.
• FlexMount20 ready: optional car-specific adaptor rings allow installation in the original mounting position.
• WireKits ready: optional plug-and-play adaptor cables connect to the factory harness or to an optional crossover.
• Made in Germany: part of the German-made COMPOSE i7 series.

Drivers & Construction

• Dome: 20 mm fine-mesh silk dome with coupling volume, Acronal-coated on both sides.
• Voice coil: 20 mm diameter.
• Magnet: neodymium.
• Housing: turned from solid aluminum.
• Coupling volume: dampened with pure lamb’s wool.

Acoustic Performance

• Impedance: 4 Ω (DC resistance 3.4 Ω).
• Sensitivity: 91.0 dB @ 2.83 V / 1 m; 88.0 dB @ 1 W / 1 m.
• Frequency response: 1,500 – 30,000 Hz.
• Resonance frequency (Fs): 950 Hz.

Crossover

• Recommended minimum highpass: 6 dB/octave: above 4,000 Hz; 12 dB/octave: above 3,000 Hz; 24 dB/octave: above 2,500 Hz.
• Crossover connection: WireKits can optionally connect the tweeter to a crossover.

Installation Notes

• Dimensions: outer diameter 32 mm (1.26″), installation diameter 27.2 mm (1.07″), installation depth 19 mm (0.75″).
• Mounting options: flush mounting with the supplied rings or surface mounting with the supplied pods; extension cables are included.
• FlexMount20: car-specific adaptor rings (sold separately) for an acoustically optimized fit in the original location.
• WireKits: automotive-grade adaptor cables (sold separately) for non-destructive connection to the vehicle harness.

Technical Specifications

Scope of Delivery

2 x Ci7 T20FM-SC
2 x Tweeter flush mount
2 x Tweeter pod
2 x Extension cable
2 x Mounting material