Helix Ci5 T25FM-CA

Helix Ci5 T25FM-CA – 25 mm Ceramic-Coated Aluminum Dome Tweeter

The Ci5 T25FM-CA is a 1″ (25 mm) tweeter from 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 i5 series sits between i7 and i3 and is aimed at listeners who want a genuine hi-fi experience; its impedances are matched to HELIX and MATCH amplifiers.

Its ceramic-coated aluminum dome provides a balanced frequency response and good decay for clear, realistic treble. The tweeter has excellent wide dispersion and off-axis response, which helps build a convincing soundstage even from OEM locations. A sturdy aluminum housing with integrated grille protects the dome, and a high-efficiency neodymium magnet provides linear magnetic flux.

Key Features

• Ceramic-coated aluminum dome: 25 mm dome for balanced frequency response and good decay.
• Wide dispersion: excellent off-axis response for a good soundstage in factory locations.
• Aluminum housing with grille: sturdy housing with integrated grille protects the dome.
• Neodymium magnet: high-efficiency magnet for linear magnetic flux.
• High sensitivity: 94 dB @ 2.83 V / 1 m.
• Compact design: installation depth of only 11.7 mm and several mounting options.
• Mounting pods included: flush-mount and angle-mount pods are supplied.
• FlexMount25 ready: optional car-specific adaptor rings for the original mounting location.
• WireKits ready: optional car-specific cables for non-destructive installation.

Drivers & Construction

• Dome: 25 mm aluminum with ceramic coating.
• Voice coil: 25 mm diameter.
• Magnet: neodymium.
• Housing: aluminum with integrated grille.

Acoustic Performance

• Impedance: 4 Ω (DC resistance 3.2 Ω).
• Sensitivity: 94.0 dB @ 2.83 V / 1 m; 91.0 dB @ 1 W / 1 m.
• Frequency response: 2,000 – 25,000 Hz.
• Resonance frequency (Fs): 1,800 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.
• Compatible crossover: Ci7 FX-UNI.2 is listed as compatible.

Installation Notes

• Dimensions: outer diameter 40 mm (1.57″), installation diameter 38 mm (1.50″), installation depth 11.7 mm (0.46″).
• Mounting options: flush-mount and angle-mount pods included.
• FlexMount25: car-specific adaptors sold separately, e.g. CFMK25 VW.1, CFMK25 FIAT.1, CFMK25 PSA.1, CFMK25 VOL.1.
• WireKits: sold separately, e.g. CWK TES1.T-225TC, CWK TES2.T-225TC, CWK FX.T-550CC – connect to the original harness or a crossover without cutting.

Technical Specifications

Scope of Delivery

2 x Ci5 T25FM-CA
2 x Tweeter flush mount
2 x Tweeter pod
2 x Mounting material
1 x Instruction manual