Helix Compose i5 Ci5 W200FM-S3 Woofer 8 Inch FlexMount 125w
Couldn't Load Pickup availability
The Helix Compose i5 Ci5 W200FM-S3 is an 8-inch (200 mm) advanced woofer rated at 125w, with 3 Ω impedance and FlexMount200 compatibility, from the Helix Compose i5 range.
200 mm / 8 inch advanced woofer with 3 Ω impedance, FlexMount200 technology and silicon-coated paper cone
Key specifications
- Size: 8 inch / 200 mm
- Power handling: 125w
- Impedance: 3 Ω
- Voice coil: 1.38" / 35 mm
- Cone material: Silicon-coated paper
- Compatible with FlexMount200 adaptors and optional WireKits
Features
- 8" / 200 mm advanced woofer with versatile physical integration options
- High efficiency and 3 Ω technology for maximised amplifier power output
- Silicon-coated paper cone combines wideband performance with deep, controlled bass reproduction
- Suits both 2-way (midbass) and 3-way (dedicated woofer) system configurations
- High-tech polymer composite basket reinforced with glass beads for rigidity and minimised ringing
- Specially shaped rubber surround for high linear cone excursion
- Aluminium dust cap reduces cone breakup at the centre and optimises frequency response in the upper midrange
- Large 1.38" / 35 mm voice coil for minimum thermal compression and high power handling
- Compact outer diameter achieves the same cone area as typical 200 mm chassis
- Automotive-grade ProConnect terminal supports conventional speaker cables or optional WireKits for a fast, secure, fail-safe connection
- Powerful magnet system with low resonance frequency for strong bass and high SPL
- Measured and verified using the KLIPPEL® Analyzer System
- Designed for optionally available car-specific FlexMount200 adaptors for acoustically optimised integration in the vehicle's original mounting location
- Compatible with optionally available car-specific WireKits for non-destructive installation
The Ci5 W200FM-S3's silicon-coated paper cone is stiff yet lightweight, with high damping to suppress unwanted resonances — the foundation of its wide midrange response. An aluminium dust cap reduces partial vibrations at the centre of the cone and refines frequency response in the upper midrange. A 35 mm voice coil handles high power levels while keeping thermal compression to a minimum.
Despite its compact outer diameter, the Ci5 W200FM-S3 achieves the same cone area as typical 8-inch drivers. Its magnet system delivers exceptional linear excursion for high SPL and strong bass power handling, while the driver still reaches well into the upper midrange. All performance data is measured and verified using the KLIPPEL® Analyzer System. If your build also requires a compact midrange driver, the Helix Compose i5 Ci5 M80FM-S3 3-inch midrange is designed for the same FlexMount system.
Explore the full range in Helix Compose i5.
Specification
| Power handling | RMS / Max 125 / 175 Watts |
|---|---|
| Impedance | 3 Ω |
| DC resistance | 3.2 Ω |
| Frequency response | 30 Hz - 8,450 Hz |
| Resonance frequency | 57.1 Hz |
| Mechanical Q factor | 3.74 |
| Electrical Q factor | 0.84 |
| Total Q factor | 0.68 |
| Compliance | 344 µm/N |
| Equivalent air volume | 21.7 L |
| Force factor | 5.6 Tm |
| Sensitivity | 93 dB @ 2.83 V / 1m 89 dB @ 1W / 1m |
| Cone | area 211 cm² |
| Moving mass | 22.7 g |
| Cone | material Silicon coated paper cone |
| Mechanical resistance | 2.16 kg/s |
| Voice coil | diameter 35 mm |
| Voice coil | winding height 15.6 mm |
| Max. linear excursion (82 % BL) | +/- 5.5 mm |
| Max. mechanical excursion | +/- 12.7 mm |
| Outer diameter | 195 mm / 7.68" |
| Installation diameter | 173.5 mm / 6.83" |
| Installation depth | 65.8 mm / 2.59" |
| Features | ProConnect terminal, FlexMount200 |
What's Included
- 2 x Ci5 W200FM-S3
- 2 x Mounting Material
Helix
About the Helix CI21807
From our tech experts at CEN
The Helix Compose i5 Ci5 W200FM-S3 is an 8 inch (200 mm) advanced woofer rated at 125w RMS, with 3 Ω impedance and a silicon-coated paper cone. It uses the FlexMount200 system and suits both 2-way midbass and 3-way dedicated woofer configurations. Sold as a pair.
Who it suits
This woofer suits car audio enthusiasts building a high-grade front stage who want deep, controlled bass alongside strong midrange reach up to 8,450 Hz. Its 3 Ω impedance extracts more power from compatible amplifiers. Browse the full Helix range to match it with a suitable amplifier and tweeter.
Our tech experts advise
The installation diameter is 173.5 mm and installation depth is 65.8 mm — confirm your door or kick panel has sufficient clearance before purchasing. FlexMount200 adaptors (sold separately) allow acoustically optimised fitting in factory locations, and optional WireKits enable non-destructive wiring. Car audio installation is priced per vehicle; contact our Nottingham team via our installation page for a quote.
Explore the full Helix range at CEN, with fast UK dispatch and expert advice from our Nottingham team. Shop all Helix
Recommended For You
Discover more top-rated gear, handpicked to go with what you're viewing
Helix News & Guides
The latest Helix product news, launches and guides from the CEN team in Nottingham.
Helix Ci5 Compact Speakers with Audiophile Sound
Intelligent, Compact Construction M50FM-S3 & M80FM-S3 The M50FM-S3 and M80FM-S3 boast an intelligent, compact construction that allows for seamless integration...
What Is a DSP? In-Car Sound Processing Explained
A DSP (digital sound processor) is the component that makes a good car system sound like a great one: it...
New at CEN: Helix Next DSP Ultra XT — The New Flagship of In-Car Processing
The Helix Next DSP Ultra XT has arrived: a 16-channel standalone processor that now sits at the very top of...
Looking for Installation?
At CEN we take pride in being able to share the quality of our work as well as being able to show what incredible products we have installed week on week.
Audiotec Fischer Brands
High-End Car Hifi components from Audiotec Fischer
More from Helix Compose i5
More options from the same range, in stock and ready to go
Highly Rated Helix Compose i5 Ci5 S200FM-S2 Woofer 8 Inch FlexMount Hybrid Subwoofer 200w RMS £254.99 /In stock
Best Seller Helix Compose i5 Ci5 M80FM-S3 Midrange Speakers 3 Inch 80 mm FlexMount 90w RMS £149.99 /In stock-
Save 15% Helix Compose i5 Ci5 S200FM-D2 Woofer 8 Inch FlexMount Hybrid Subwoofer 200w RMS RRP£299.99£254.99 / Save 15%In stock 
Save 17% Best Seller Helix Compose i5 Ci5 T25FM-CA Tweeters 1 Inch 25mm FlexMount Aluminum Dome RRP£149.99£124.99 / Save 17%In stock
Frequently Asked Questions
Q: Will these speakers fit my car?
A: Most car speakers are standard sizes, but mounting depth and fitting rings vary by vehicle. Check the size in the Specification tab against your vehicle, or contact CEN with your registration and we will confirm fitment and any adapters or fitting kits you need.
Q: Do I need an amplifier to run these speakers?
A: Not always. Most speakers will run from a standard head unit, but a dedicated amplifier lets them perform at their best, particularly for component sets and higher power handling models. The RMS figure in the Specification tab is the guide to how much clean power they can use.
Q: What is the difference between coaxial and component speakers?
A: Coaxial speakers combine the tweeter and woofer in one unit for a simple like-for-like upgrade. Component sets separate the tweeter and woofer with a crossover for better imaging and detail, and suit installs where sound quality is the priority.
Q: Do these come as a pair?
A: Unless stated otherwise, car speakers are sold in pairs. Check the product title and What's Included tab, which lists exactly what is in the box.
Q: Can CEN fit these speakers for me?
A: Yes. CEN offers professional installation from our Nottingham premises. Contact us to book an installation slot or ask for a fitting quote.
Q: Is the Ci5 W165FM-S3 a full-range speaker?
A: No. It is a midbass woofer covering 50 Hz to 5,000 Hz, designed to be used with a separate tweeter and crossover or an amplifier with DSP.
Q: What impedance is the HELIX Ci5 W165FM-S3?
A: It is a 3-ohm woofer. HELIX matches this impedance to its HELIX and MATCH amplifiers for higher efficiency and maximum sound pressure.
Q: What mounting depth does the Ci5 W165FM-S3 need?
A: Installation depth is 66.8 mm with a 142 mm installation diameter, and the FlexMount system adapts it to a wide range of factory speaker positions.
