Helix Ci7 C165.2FM-S3

Helix Ci7 C165.2FM-S3 – 165 mm 2-Way High-End Coaxial Speaker

The Ci7 C165.2FM-S3 is a 6.5″ (165 mm) 2-way coaxial speaker 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 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. It combines the Ci7 W165FM-S3 midbass with the Ci7 T20FM-SC tweeter in one coincident unit.

Because tweeter and midbass share one sound axis, both radiate from the same point, so the speaker behaves like a point source with wide dispersion and precise imaging. The midbass uses the UHD paper cone, a basket of glass-bead reinforced polymer composite and a ProConnect terminal, while the 20 mm silk dome tweeter has an integrated coupling volume damped with pure lamb’s wool. The speaker has no built-in crossover – it is designed for active 2-way operation or the optional passive Ci7 FX-UNI.2.

Key Features

• 2-way coincident coaxial: tweeter and midbass on one axis for point-source behaviour.
• Wide dispersion and precise imaging: result of the point-source design.
• 20 mm silk dome tweeter: integrated, damped coupling volume for low resonance and a low crossover point.
• UHD paper cone midbass: handmade Ultra High Damping cone for excellent impulse and frequency response.
• 37 mm midbass voice coil: for low thermal compression and high power handling.
• Glass-bead reinforced polymer basket: rigid, low self-resonance, reduced flux modulation, thermally resistant, compact.
• 3 Ω system impedance: more efficiency and maximum sound pressure with HELIX and MATCH amplifiers.
• ProConnect terminal: automotive-grade midbass terminal, interlocked and reverse-polarity protected.
• FlexMount165 ready: car-specific adaptor rings for the original mounting location.
• WireKits ready: optional cables for non-destructive connection to the factory harness.
• Made in Germany: part of the German-made COMPOSE i7 series.

Drivers & Construction

• Included drivers: Ci7 W165FM-S3 midbass and Ci7 T20FM-SC tweeter combined coaxially.
• Midbass: UHD paper cone, cone area 131 cm², 37 mm voice coil (13.4 mm winding height), glass-bead reinforced polymer basket, ProConnect terminal, 3 Ω (Re 3.0 Ω).
• Tweeter: silk dome with coupling volume damped with lamb’s wool, 20 mm voice coil, 4 Ω.

Acoustic Performance

• Power handling: 150 W RMS / 225 W max.
• System impedance: 3 Ω.
• Sensitivity: 92 dB @ 2.83 V / 1 m; 88 dB @ 1 W / 1 m.
• Frequency response: 50 – 30,000 Hz.
• Midbass T/S parameters: Fs 59 Hz, Qms 3.99, Qes 0.64, Qts 0.55, Vas 13.3 l, Cms 572 µm/N, BxL 4.7 Tm, Mms 13.0 g, Rms 1.21 kg/s.
• Midbass Xmax: ±3.7 mm.

Crossover

• No integrated crossover: the speaker is supplied without a crossover.
• Active 2-way: requires two amplified DSP channels per speaker; a highpass filter for the tweeter must be set in the DSP or DSP amplifier.
• Passive 2-way: possible with the optional Ci7 FX-UNI.2 crossover (sold separately).

Installation Notes

• Dimensions: outer diameter 165.0 mm (6.50″), installation diameter 142.0 mm (5.59″), installation depth 65.8 mm (2.59″).
• FlexMount165: vehicle-specific adaptors (e.g. CFMK165 GM.1) sold separately.
• Wiring: separate tweeter and midbass connection cables are supplied; WireKits, standard speaker cables or flat-plug adaptor cables can be used with ProConnect.

Technical Specifications

Scope of Delivery

2 x Ci7 C165.2FM-S3
2 x Tweeter connection cable
2 x Midbass connection cable
1 x Mounting material
1 x Instruction manual