Helix Ci5 W165FM-S3

Helix Ci5 W165FM-S3 – 6.5″ / 165 mm advanced 3 Ω midbass with phase plug

The Ci5 W165FM-S3 is a 165 mm midbass from the HELIX COMPOSE i5 series, which sits between the i7 and i3 lines and is aimed at listeners looking for a true hi-fi experience in the car. Its 3 Ω impedance is matched to HELIX and MATCH amplifiers for high efficiency, and the driver is designed to work in both 2-way and 3-way speaker systems.

What sets it apart is the combination of a light, stiff silicon-coated paper cone with an integrated phase plug. The phase plug reduces mechanical compression, improves dispersion and sharpens upper-midrange transients, and its colour matches the dome of the Ci5 T25FM-CA tweeter. A large 37 mm voice coil, a glass-bead reinforced polymer basket, the ProConnect terminal and readiness for car-specific FlexMount165 adaptors complete the package.

Key Features

• Advanced 6.5″ midbass: 165 mm driver combining sound performance with versatile mounting options
• 3 Ω technology: high efficiency and impedance matched to HELIX and MATCH amplifiers for more output from the amplifier
• Silicon-coated paper cone: light and stiff, with the coating damping unwanted resonances for good impulse and frequency response
• Integrated phase plug: improves upper-midrange reproduction, reduces compression and raises the thermal power handling of the voice coil
• 2-way and 3-way capable: suitable both as midbass in a 2-way set-up and in 3-way systems
• Glass-bead reinforced polymer basket: a high-tech polymer composite that is rigid, rings less, avoids flux modulation, copes well with heat and allows a more compact basket
• Shaped rubber surround: specially contoured to allow high linear cone excursion
• 37 mm voice coil: large 1.46″ voice coil for low thermal compression and high power handling
• Strong magnet system: for high efficiency and low distortion
• ProConnect terminal: automotive-grade, interlocking terminal with reverse-polarity protection; accepts standard speaker cable or flat plugs via the optional WireKits and withstands high electrical and mechanical stress
• FlexMount165 ready: designed for optional car-specific FlexMount165 adaptor rings for installation in the original mounting position
• WireKit ready: designed for optional car-specific WireKits – adaptor cables built to automotive standards that connect the speaker to the factory harness or an optional crossover without cutting the original wiring

Drivers & Construction

• Cone: paper with silicon coating, integrated phase plug
• Voice coil: 37 mm diameter, 13.7 mm winding height
• Basket: polymer composite reinforced with glass beads
• Surround: specially shaped rubber surround
• Terminal: ProConnect
• Delivered as: pair (2 × Ci5 W165FM-S3)

Acoustic Performance

• Power handling: 125 W RMS / 175 W max
• Impedance: 3 Ω (DC resistance 3.1 Ω)
• Sensitivity: 92 dB @ 2.83 V / 1 m; 88 dB @ 1 W / 1 m
• Frequency response: 50 Hz – 5,000 Hz
• Thiele/Small: Fs 50 Hz, Qms 2.38, Qes 0.50, Qts 0.41, Vas 17.9 l, Cms 742 µm/N, Bl 5.2 Tm, Sd 131 cm², Mms 14.0 g, Rms 1.83 kg/s
• Xmax: ±3.9 mm

Installation Notes

• Outer diameter: 165 mm / 6.5″
• Installation diameter: 142 mm / 5.59″
• Installation depth: 66.8 mm / 2.63″
• FlexMount165: a wide range of car-specific CFMK165 adaptor rings is listed as accessories (e.g. CFMK165 VW.1, MB.1, SKO.1, HYU.1, AUD.1, BMW.1, FOR.1, VOL.1, TOY.1)
• WireKits: optional car-specific adaptor cables for connection to the factory harness

Technical Specifications

Scope of Delivery

2 x Ci5 W165FM-S3
2 x Mounting material