Helix Ci5 M50FM-S3 – 50 mm Wideband Speaker with FlexMount50

The Ci5 M50FM-S3 is a 2″ (50 mm) advanced wideband driver 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 for listeners who want true hi-fi sound, and the 3 Ω design is matched to HELIX and MATCH amplifiers.

Its outer diameter is smaller than that of typical 2″ drivers, so it fits tight OEM openings, angled mounts and housings where 2- or 3-way setups are difficult. Thanks to its broad frequency range it allows layouts without a separate tweeter and is an excellent choice for center, full-range and DSP applications. The silicon-coated paper cone offers internal damping, an aluminum dust cap bonded to the voice coil improves transient response, and a push-pull neodymium magnet raises sensitivity while keeping distortion low.

Key Features

Compact wideband driver: 2″ driver with flexible physical integration.
Wide frequency range: 300 – 20,000 Hz, allowing system layouts without a separate tweeter.
3 Ω technology: more efficiency and amplifier output with HELIX and MATCH amplifiers.
Silicon-coated paper cone: high internal damping for good impulse and frequency response.
Aluminum dust cap: light and rigid, bonded directly to the voice coil for better transient behaviour.
Rubber surround: specially shaped, with an optimized magnet for large linear excursion (Xlin ±2.5 mm).
Larger effective cone area: surround design allows a smaller installation diameter and a larger effective cone area than typical 50 mm speakers.
Push-pull neodymium magnet: higher sensitivity and low distortion.
Glass-bead reinforced polymer basket: rigid, low ringing, heat resistant and compact.
FlexMount50 ring included: universal CFM50 MULTI.1 ring for car-specific or universal fitting, plus mounting ring with grille.

Drivers & Construction

Cone: silicon-coated paper, cone area (Sd) 19.6 cm².
Dust cap: aluminum, bonded to the voice coil.
Voice coil: 20 mm diameter, 7 mm winding height.
Magnet: push-pull neodymium system.
Basket: polymer composite reinforced with glass beads.
Surround: specially shaped rubber surround.

Acoustic Performance

Power handling: 70 W RMS / 100 W max.
Impedance: 3 Ω (DC resistance 3.1 Ω).
Sensitivity: 89 dB @ 2.83 V / 1 m; 85 dB @ 1 W / 1 m.
Frequency response: 300 – 20,000 Hz.
T/S parameters: Fs 240 Hz, Qms 3.09, Qes 0.80, Qts 0.68, Vas 0.16 l, Cms 300 µm/N, BxL 2.8 Tm, Mms 1.43 g, Rms 0.71 kg/s.
Excursion: max. linear excursion (Xlin) ±2.5 mm; max. mechanical excursion (Xmax) ±3.5 mm.

Installation Notes

Dimensions: outer diameter 59.8 mm (2.34″), 70.0 mm (2.75″) with universal mounting ring; installation diameter 50.9 mm (2.00″); installation depth 25.2 mm (0.99″).
FlexMount50: universal CFM50 MULTI.1 rings included; car-specific rings (e.g. for Audi, Ford, Mercedes) can be found with the FlexMount Finder.
Included mounting parts: speaker gaskets and mounting rings with grille are supplied.

Technical Specifications

Power handling RMS / Max.	P	70 / 100 Watts
Impedance	Z	3 Ω
DC resistance	Re	3.1 Ω
Frequency response		300 Hz – 20,000 Hz
Resonance frequency	Fs	240 Hz
Mechanical Q factor	Qms	3.09
Electrical Q factor	Qes	0.80
Total Q factor	Qts	0.68
Compliance	Cms	300 µm/N
Equivalent air volume	Vas	0.16 L
Force factor	BI*	2.8 Tm
Sensitivity	SPL	89 dB @ 2.83 V / 1m 85 dB @ 1W / 1m
Cone area	Sd	19.6 cm²
Moving mass	Mms	1.43 g
Cone material		Silicon coated paper cone
Mechanical resistance	Rms	0.71 kg/s
Voice coil diameter	ø	20 mm
Voice coil winding height		7 mm
Max. linear excursion	Xlin	+/- 2.5 mm
Max. mechanical excursion	Xmax	+/- 3.5 mm
Outer diameter	ø	59.8 mm / 2.34″
Outer diameter with universal mounting ring	ø	70.0 mm / 2.75″
Installation diameter	ø	50.9 mm / 2.00″
Installation depth		25.2 mm / 0.99″
Features		Powerful push-pull neodymium magnet system, FlexMount50

Scope of Delivery

2 x Ci5 M50FM-S3
2 x Universal FlexMount CFM50 MULTI.1
2 x Speaker gasket
2 x Mounting ring with grille
1 x Mounting material

5 cm (2″)

Helix Ci5 M50FM-S3