Helix Ci3 K165.2FM-S2 MK2

Helix Ci3 K165.2FM-S2 MK2 – 6.5″ 2-way FlexMount component system, 2 Ω

The Ci3 K165.2FM-S2 MK2 is a 165 mm 2-way component set from the HELIX COMPOSE i3 line, part of the HELIX COMPOSE platform, a reworked generation of universal speakers that Audiotec Fischer develops in the vehicle for the vehicle, aiming to merge the flexibility of a universal speaker with the fit advantages of vehicle-specific systems. It pairs a 6.5″ midbass with a 0.75″ tweeter and is designed to fit easily into cars and to work with HELIX and MATCH amplifiers. This is the 2 Ω version of the kit, intended to extract maximum output from a suitable amplifier.

The low 2 Ω impedance and high efficiency let the amplifier deliver more power, and driver development was verified with the Klippel Analyzer System. The midbass combines a Cenosphere-coated paper cone with a glass-bead-reinforced polymer basket; the tweeter uses a black aluminium dome and a neodymium magnet. FlexMount165 and FlexMount20 compatibility, COMPOSE Connect / ProConnect plug-in connections and the separate Ci3 FX-UNI.2 crossover with WireKit support allow installation in original mounting positions without cutting the vehicle wiring.

Key Features

• 2 Ω technology: high efficiency for maximum power output from the amplifier
• Klippel-verified: driver development verified with the Klippel Analyzer System
• Automotive-grade connectors: COMPOSE Connect and ProConnect for secure, fail-safe wiring
• 20 mm aluminium tweeter: black aluminium dome, light yet stiff, for precise and detailed highs
• Neodymium tweeter magnet: refined, highly efficient, with linear magnetic flux
• Flexible tweeter mounting: compact tweeter with several mounting options; flush and angle pods included
• Cenosphere midbass cone: 165 mm coated paper cone for precise, detailed reproduction
• Glass-bead reinforced basket: rigid polymer composite that reduces ringing
• Powerful magnet system: for high efficiency and good impulse response
• Polyurethane dustcap: tuned for the upper midrange
• Separate Ci3 FX-UNI.2 crossover: compact, 6-step tweeter level adjustment, tweeter protection, 12 dB tweeter slope
• FlexMount165 / FlexMount20: optional adaptors for installation in the original vehicle mounting positions

Drivers & Construction

• Tweeter: 20 mm (0.75″) black aluminium dome, neodymium magnet, 20 mm voice coil, ultra-compact, FlexMount20 compatible
• Midbass: Paper cone with Cenosphere coating – hollow microspheres embedded in a polyamide layer raise stiffness and internal damping while keeping the cone light; polyurethane dustcap; 25 mm voice coil (11.3 mm winding height); ProConnect terminal; FlexMount165 compatible
• Basket: Polymer composite basket reinforced with glass beads – rigid, low in self-resonance, reduces flux modulation of the magnet system, heat-resistant and compact for tight mounting spaces
• System: 2 tweeters, 2 midbass drivers and 2 separate crossovers form the stereo set

Acoustic Performance

• Power handling: 100 W RMS / 150 W max
• Impedance: 2 Ω (midbass 2 Ω, Re 1.8 Ω; tweeter 4 Ω)
• Sensitivity: 94 dB @ 2.83 V / 1 m; 88 dB @ 1 W / 1 m
• Frequency response: 60 Hz – 25,000 Hz
• Midbass T/S parameters: Fs 74 Hz, Qts 0.74, Qes 0.92, Qms 3.92, Vas 8.8 l, Sd 133 cm², Mms 12.5 g, BL 3.4 Tm, Cms 370 µm/N, Xmax ±3.7 mm
• Tweeter: Fs 1,800 Hz

Crossover

• Type: separate Ci3 FX-UNI.2 crossover, 103.3 × 50.4 × 25.0 mm, compact for tight spaces
• Tweeter section: 12 dB/octave highpass with integrated tweeter protection
• Level adjustment: 6-step tweeter level control to suit the mounting position
• Midbass section: 6 dB lowpass
• Connectivity: compatible with COMPOSE Connect and car-specific WireKits

Installation Notes

• Midbass: mounting diameter 142 mm, mounting depth 60.7 mm, outer diameter 165 mm
• Tweeter: mounting and outer diameter 32 mm, mounting depth 9.8 mm; flush and angle pods included
• FlexMount165: optional vehicle-specific midbass adaptors, e.g. CFMK165 VW.1, VW.2, MB.1, SKO.1, HYU.1, AUD.1, VOL.1
• FlexMount20: optional tweeter adaptors, e.g. CFMK20 BMW.1, TES.1, TES.2, POR.1, MB.1
• COMPOSE Connect: plug-in housings for standard flat plugs – no soldering, polarity reversal prevented
• WireKits: optional locking adaptor cables to the factory harness, e.g. CWK BMW.FX-550CC
• Other accessories listed: CiA SG165, CiA FR165.10

Technical Specifications

Scope of Delivery

2 x Tweeter Ci3 T20FM-AL MK2
2 x Midbass Ci3 W165FM-S2
2 x Crossover Ci3 FX-UNI.2
2 x Lowpass cable crossover Ci3 FX-WLP.2
2 x Tweeter mounting accessories
2 x COMPOSE Connect Kit
1 x Mounting material