SKU: 78514199660

Helix Compose Ci3 C165.2FM-S3 MK2- 6.5" 3 Ohm Coaxial Speakers

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Description

Helix Compose Ci3 C165.2FM-S3 MK2- 6.5" 3 Ohm Coaxial SpeakersHELIX Ci3 C165. 2FM S3 MK2 HELIX COMPOSE. The perfect speaker for any composition. Born out of the increasingly demanding challenges of modern automobile technology and the HELIX typical pursuit of intelligent solutions, we made the progressive redesign of proven universal speaker systems our mission. The result: our innovative HELIX COMPOSE platform that, according to the motto "developed inside the vehicle, for the vehicle", combines classic

HELIX Ci3 C165.2FM-S3 MK2

HELIX COMPOSE. The perfect speaker for any composition.

Born out of the increasingly demanding challenges of modern automobile technology and the HELIX-typical pursuit of intelligent solutions, we made the progressive redesign of proven universal speaker systems our mission. The result: our innovative HELIX COMPOSE platform that, according to the motto "developed inside the vehicle, for the vehicle", combines classic universal speakers with the advantages of vehicle-specific systems. Innovative materials and the latest technologies paired with smart, practical engineering - the best of both worlds in harmony: high efficiency, fantastic sound quality and enormous dynamics that fit in any vehicle. HELIX COMPOSE – universal speakers evolved.

Performance highlight

The i3 coaxial systems give you everything you would expect from a great 2-way system: A first-class sound experience that, thanks to the use of high-quality materials and its particularly smart engineering, conveniently finds its way into the automobile. All components harmonize perfectly and form an ideal team with our HELIX and MATCH amplifiers, guaranteeing maximum performance and power output at all times. Furthermore, we implemented our new, mechanical technologies with a clear focus on safety during connection and operation for the purpose of creating ideal conditions for the integration into the vehicle with maximum compatibility.

High efficiency

HELIX COMPOSE equals smart engineering and accordingly implements highly efficient 3 Ohm technology, that perfectly harmonizes with all HELIX and MATCH amplifiers and at the same time allows a clearly perceptible plus in efficiency and maximum sound pressure.

Cenosphere paper cone

With the innovative "Cenosphere" coating, hollow spheres are incorporated into a polyamide layer that is applied to the cone. This process increases the stiffness and also optimizes its internal damping. The result is an exceptionally stable yet lightweight cone that offers outstanding precision in sound reproduction.

High-tech polymer basket

All HELIX COMPOSE i7 and i3 speaker baskets are made of a high-tech polymer composite, which has been additionally reinforced with glass spheres. The result: maximum stability with minimal self-resonance, while also eliminating flux modulation of the magnetic system and maximum resistance to thermal influences. Last but not least, this allows for much more compact basket dimensions and thus simplified installations in cramped installation conditions.

Natural brilliance and precise detail resolution

The 0.75” / 20 mm tweeter features an elegant black aluminum dome that strikes the perfect balance between low weight and high rigidity. Combined with the refined, highly efficient neodymium magnet system, it delivers an even more precise, clear, and detailed high-frequency response. The result is natural brilliance with outstanding resolution and impressive dynamics – for an exceptional listening experience.

FlexMount165 – Universal meets car-specific

FlexMount is a mounting system based on specially developed adaptor rings, allowing the installation of COMPOSE FlexMount speakers in an almost infinite number of vehicles. Thus, the universal loudspeaker effortlessly becomes a vehicle-specific loudspeaker, that can be easily installed in the original installation position of the vehicle in an acoustically optimized way with the matching FlexMount adaptor ring.

ProConnect – The new industry standard

Our innovative ProConnect terminal is the new industry standard: A professional, automotive connector, allowing the safe use of conventional speaker cables, while also being ideally designed for connection via flat plug with our WireKits, offering maximum flexibility in the design of the sound system upgrade. Furthermore, the connection is interlocked, offers reverse polarity protection and is electrically and mechanically highly stressable.

WireKits – Plug & Play at its best

Our WireKits realize the connection of HELIX COMPOSE coaxial speaker system to the original wiring harness in the most comfortable way. With manufacturing according to the high standards of the automotive industry, these arrestable adaptor cables meet all requirements for the harsh environmental conditions that installers are facing in vehicles every day.

Features

  • 2-way performance coaxial speaker system which combines outstanding sound quality with versatile physical integration options
  • High efficiency and 3 Ohms technology for maximized power output of the amplifier
  • Automotive grade ProConnect connection terminal allows the use of conventional speaker cables or a fast, secure and fail-safe connection via optionally available WireKits
  • Tweeter
    • 0.75” / 20 mm performance tweeter with black aluminum dome for accurate, pure and detailed treble response
    • High-quality aluminum dome with perfect balance of low weight and high rigidity – for natural brilliance and fine detail reproduction
    • Refined highly efficient neodymium magnet for high magnetic flux linearity and optimized performance
  • Midbass
    • 6.5" / 165 mm midbass with unique Cenosphere coated paper cone for precise and detailed sound reproduction
    • High-tech polymer composite basket reinforced with glass beads for enormous rigidity and minimized ringing
    • Powerful magnet system for high efficiency and optimum impulse response
  • Crossover
    • Integrated with 6 dB slope
  • Designed for the optionally available car-specific FlexMount165 adaptors which allow an acoustically optimized and professional integration in the original mounting location of the vehicle
  • Designed for optionally available, car-specific WireKits which allow a non-destructive integration

Technical data

Power handling RMS / Max.  P 100 / 150 Watts
Frequency response   60 Hz - 25,000 Hz
Impedance Z 3 Ω
Sensitivity  SPL 92 dB @ 2.83V / 1m
88 dB @ 1W / 1m
Outer diameter ø 165.0 mm / 6.50”
Installation diameter ø 142.0 mm / 5.59”
Installation depth    60.7 mm / 2.39”
   
Midbass
Impedance Z 3 Ω
DC resistance Re 3.1 Ω
Resonance frequency Fs 72 Hz
Mechanical Q factor Qms 4.02
Electrical Q factor Qes 1.04
Total Q factor Qts 0.82
Compliance Cms 466 μm/N
Equivalent air volume Vas 11.5 L
Force factor B*l 3.8 Tm
Cone area Sd 133 cm2
Moving mass Mms 10.4 g
Mechanical resistance Rms 1.17 kg/s
Voice coil diameter  ø 25 mm

Voice coil winding height

   10.5 mm
Max. linear excursion Xmax +/- 3.2 mm
   
Tweeter  
Voice coil diameter ø 20 mm
   
Features  
Tweeter   Aluminum dome and neodymium magnet
Midbass  

Paper with Cenosphere coating, ProConnect terminal
and FlexMount165
Crossover   Integrated, 6 dB highpass

Compatibility

  • FlexMount165
  • WireKits
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 78514199660

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4.7 ★★★★★
Based on 28 reviews
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Product Reviews
K
Verified Purchase
Kindle Customer
Grantham, US
★★★★★ 5
Excellent story
Format: Kindle
This book is worth your time. It is a great introduction to a variety of scientific disciplines without insulting the reader. It also respects and understands humanity, engineering, history and political science. Then it lays that foundation to tell the story of a unique friendship of two beings with mutual goals who have to communicate and problem solve together. Along the way, you can really contrast how Grace and Rocky do it, vice the Hail Mary team did it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 22, 2026
H
Verified Purchase
Hanay21
New York, US
★★★★★ 5
A book worth rereading
Format: Hardcover
This was a book club pick. Honestly, I wouldn't have chosen to read this myself, but I'm glad that I did. I would have missed out on an incredible story. I've been reading a lot of thriller and fantasy books lately, that I forgot how much I enjoy sci-fi. This brought it back for me. There's a lot of science-heavy discussions in the book and I loved it! When I got to a subject or term I didn't know, I would go online and learn more about it. I feel that Grace is a dork like me because he wouldn't curse. He had little anecdotes he uses in place of swearing. Something I definitely do myself! A lot of the book is the MMC talking to himself. Surprisingly, it worked. There's so much humor that it kept the story going. There was not a lull. Usually I dislike info-dumping as an introduction to get all the background story told, but I didn't mind it at all. Maybe I'm being biased because I love science talk. **SPOILERS AHEAD** What makes the whole plot engaging is the fact that the plot doesn't seem too fantastical. It's something that could happen. There's a lot of ethics and morals involved in determining what should be done. I would hate to be in a position where I have to chose what's best for everyone. That's why Stratt is a necessary character. I hated some of her decisions and how she operated, but you need someone who's focused on the general welfare of humanity. I would be too focused on myself, my family, etc. As much as it hurts to admit, I'm selfish (and a coward) like Grace. I wouldn't want to die. But was it right for Stratt to force him on the mission? This could also be taken religiously. If God has a plan and things happen for a reason, is it our right to deter what's going to happen? God wiped out the world many times because of humanity's sins, what if this was God's doing? So many questions and debates on right vs wrong, ethics vs morals, and religion vs humanity made for a incredible book club discussion. I love how this book ended. I wish I could continue reading about Rocky and Grace's adventures, it's that fascinating. However, I think Grace staying on Erid was the best outcome. If the roles were reversed, I don't think Rocky would have the same welcome. I feel that those in charge would have dissected and kept Rocky hostage, all in the name of science. Just as the Astrophage were first introduced, the first things the scientists did was poke and probe. Essentially torturing the Astrophage to see what makes them tick. I think Rocky would have the same fate. Oh, and my favorite part is the relationship between Rocky and Grace. I cried so many times when I was reading. Scared that something bad was going to happen to either of them. Especially in the scene where Rocky busted out of his tunnel to save Grace. I got upset and told the book that 'if Rocky dies, I swear, this is the worst book ever!' And the scene where Rocky learns about radiation poisoning. How he slowly becomes aware of what happened to his crew, his friends. I was a mess. This book is definitely one that I could go back and reread. I did watch the movie afterwards. There's a lot of differences to adapt the story to screen, but it was okay. They got the humor down pat, but I didn't get the direness of the whole situation nor the special bond that both MCs had.
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Reviewed in the United States on April 20, 2026
G
Verified Purchase
Gilligan
Los Angeles, US
★★★★★ 5
A Brilliant, Emotional, and Unforgettable Sci-Fi Adventure
Format: Paperback
Project Hail Mary by Andy Weir is one of those rare novels that delivers everything you could want from science fiction: gripping suspense, fascinating science, humor, heart, and a genuinely moving story about survival and friendship. The novel follows Ryland Grace, a middle school science teacher who wakes up alone on a spacecraft with no memory of who he is or why he’s there. As his memories slowly return, the stakes become clear: humanity is facing extinction, and he may be the only person who can stop it. The mystery unfolds at a perfect pace, blending high tension with moments of discovery that keep you turning the pages. What makes this book stand out is how seamlessly it combines hard science with accessibility. Like the author’s earlier work, the scientific details feel authentic and well researched, but they never overwhelm the story. Instead, the problem-solving becomes the engine of the plot. Each obstacle feels real, and the solutions are both clever and satisfying. The biggest surprise—and the emotional core of the novel—is the relationship that develops during the mission. Without giving anything away, it adds warmth, humor, and depth that elevate the story far beyond a typical survival thriller. By the end, the novel becomes less about science and more about courage, trust, and the willingness to sacrifice for others. The pacing is excellent throughout, with a balance of suspense, humor, and heartfelt moments. If there’s a small drawback, it’s that some plot developments feel a bit convenient. But the strong characters and emotional payoff more than make up for it. Overall, this is a must-read for fans of science fiction, space exploration, and anyone who enjoys smart, character-driven storytelling. It’s thrilling, funny, deeply human, and surprisingly emotional. I finished it feeling both entertained and uplifted. Highly recommended.
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Reviewed in the United States on February 19, 2026
D
Verified Purchase
Daniel
Chelsea, US
★★★★★ 5
Proof that lightning strikes twice ... Weir has done it again!
Format: Hardcover
According to a 2003 article on the NASA website, "NASA-funded scientists have recently learned that cloud-to-ground lightning frequently strikes the ground in two or more places ..." and that the third and fourth strokes of a lightning flash will follow the same path as the second stroke. In other words, lightning DOES strike the same place twice. But you don't need to search the web for this information. If you want proof that lightning strikes twice, just read Andy Weir's newest book, Project Hail Mary, and you'll see that Weir has created a giant sci-fi bestseller, in the same electric path as The Martian. Ryland Grace has a puzzle on his hands. He wakes up without a clue as to where he is, but he seems to be alone except for a computer AI that was keeping him alive. Unfortunately it didn't seem to be doing the same for two others in his ... wherever he is ... as he notes the decayed corpses in their creches on the ... well, it's a ship. A space ship. And bit by bit Grace puts the pieces of the puzzle together. An alien microbe has been discovered. Ryland Grace is brought on to the science team to learn more about the life form because Grace, currently a middle school science teacher, wrote papers about the notation that there does not need to be water to create life. Only in a biozone such as Earth's would water be needed, but other building blocks could be used in other systems. The science community as a whole mocked Grace, which is why he left and went on to teach kids, but now, he may be the best suited to understand this new life form. And as he remembers more and more, he also remembers that this life form is feeding on the energy output of the sun, which is decreasing the energy that gets to Earth, which spells disaster - as in the end of all life as currently known - on Earth if something isn't done. Scientists discover that Sol isn't the only star that is losing its energy output - likely due to the alien consumption, but that there is one star, in the center of all the known stars losing their energy, that remains constant with its output. In which case, the answer to the survival for Earth is likely found there, at Tau Ceti. The world's best scientific minds come together (by force and coercion) to create a ship that can get to Tau Ceti in twelve years (using the alien microbe as fuel) with shuttle pods to bring back answers to how to save the planet, but for the crew, it's a one-way trip. Knowing why he's there is only the first puzzle for Grace. Now he has to figure out how to save Earth. There's a very small window of time for him to discover the way to save the human race and get the answers sent back. Take too long and the shuttles will return to a dead planet. This book is amazing. Author Andy Weir brings us back to the magic that made The Martian so successful - an abandoned scientist trying to survive. But Ryland Grace's story is more complicated because he's not just trying to survive, but also help humanity survive. There's lots and lots of science - which is part of Weir's writing signature - and there's also a really wonderful story. It's hard for me to tell you just what I liked about this book because anything I write will be a spoiler and a huge part of the joy in this book is making the discoveries with Ryland Grace. Grace is our main character, but through the liberal use of flashbacks, we have a full cast of characters - at least one quite important to the story. Everyone is unique and individual which makes it easy to read, but just as with The Martian, where Mark Watney's personality carries the story, Ryland Grace here is the smart-mouth, sometimes funny, obsessed scientist infusing his personal tastes into his discoveries. He's also quite smart - which is good since he will need his intellect to save all of humanity. This is a page-turner. I did not want to put this book down. Neither did my 21 year old son who picked up my copy after I was well into it and finished it before I did. And days later he's still talking about how much he liked it and quoting sections of it to me at the dinner table. I hope Ballantine Books will do a very large print run because this is going to be huge seller and you definitely don't want to miss out on the biggest thing to come out in 2021. Looking for a good book? Project Hail Mary by Andy Weir is proof that lightning strikes twice as this has all the excitement and energy of Weir's debut novel, with a more complicated storyline that will hold the reader all the way to the end.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 10, 2021
J
Verified Purchase
Joe Rak
Port Orchard, US
★★★★★ 4
Excellent Hard Sci-Fi… Until the Politics Pull You Out
Format: Kindle
I was really excited to dive into Project Hail Mary. As a longtime Isaac Asimov fan, I’ve been craving fresh, modern hard science fiction that actually respects the science. This book delivered — at least for a while. The author injects real science into the story in a way that’s both fun and fantastic. You don’t need to be an engineer to follow it; a solid high-school education is plenty. The concepts stretch your imagination without ever feeling impossible, and for the first chunk of the book I was hooked. I genuinely thought I’d found a new favorite author. Then the jarring interruptions started. Out of nowhere you get yanked out of the immersive sci-fi world by modern political pandering that feels completely unnecessary. A random parenthetical about Columbus “discovering an already inhabited world” when comparing something to the New World. Casual pronoun lectures. Characters selected or described by race and identity in ways that scream “check the boxes.” These moments don’t serve the story — they feel injected. Once you notice the author’s leanings, it becomes hard to unsee. Each time it happens, the fantasy evaporates. It takes several chapters to sink back into the story… only for the next micro-lecture to pull you right back out. Overall, I loved the writing, the hard science, and the imagination. It’s some of the best sci-fi I’ve read in years. I just wish the author had trusted the story instead of sneaking in real-world politics. It’s like eating the best meal of your life… and then finding a hair or two in it. Strongly recommended for the sci-fi, with the above caveat.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 17, 2026

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