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Helix Blue B4X

4" 2-way car speakers

18 Reviews | 2 questions - 3 answers

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Item # 975B4X

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Our take on the Helix Blue B4X

Helix builds their low-profile Blue Series speakers to fit into more factory speaker locations while maintaining their high standards for sound quality. Helix earned its reputation by paying attention to the details, and these speakers really uphold the family name.

German engineering meets car audio

Helix builds their low-profile Blue Series speakers to fit into more factory speaker locations while maintaining their high standards for sound quality. Helix earned its reputation by paying attention to the details, and these speakers really uphold the family name.

Blue Series B4X 4

The drivers

You'll hear excellent high-frequency detail from the 1/2" Mylar dome tweeter, while the polypropylene woofer supplies solid midrange. If you want to enjoy the little details in your music without breaking the bank, you'll want to check out these Helix speakers. Grilles are included.

Product Highlights:

  • 4" 2-way speakers (pair)
  • injection-molded polypropylene woofer cone with urethane surround
  • 1/2" Mylar dome tweeter
  • power range: 5-25 watts RMS (75 watts peak power)
  • frequency response: 100-22,000 Hz
  • sensitivity: 89 dB
  • top-mount depth: 1-13/16"
  • grilles included
  • warranty: 2 years
  • Our 60-day money-back guarantee

What's in the Box:

  • Two 4" Coaxial speakers
  • 2 Grilles
  • 8 Speed clips
  • Eight 1" Self-tapping screws
  • 8 Mounting clips
  • Two 10' Lengths of speaker wire (female quick-slides on one end and tinned wire on other)
  • Instruction manual (English/ German)
  • Template

Installed on a 1979 240d Mercedes, They sound great.

Max C, Milwaukee, WI


Helix Blue B4X Reviews

Average Customer Review(s):

(18 Reviews)

Speakers and installation

Max C from Milwaukee, WI on 10/29/2014

1979 Mercedes-Benz 240D
Crutchfield Customer Review (What's this?)

Installed on a 1979 240d Mercedes, They sound great.

Pros: Sound great

Cons: Two of the clips had to be removed. The speaker sits slightly too high and the grills jut out slightly and a side winder screwer is necessary to get at the screws by the windshield and splicing the wires is necessary to get the speakers connected.

good speaker but doesnt fit 1986 Mercedes

HPC from California on 10/29/2014

Crutchfield Customer Review (What's this?)

The speakers sound great for the price, but Crutchfield listed them as a direct fit for 1986 Mercedes 560sl. The speakers did not fit this car without having to modify the speaker and dash a bit.

Pros: sound very good for the price and size

Cons: had to modify speaker and dash to make them fit.

DIY Bluetooth box

matt from Omaha, NE on 10/9/2014

2008 Volkswagen Passat
Crutchfield Customer Review (What's this?)

Really god sound from a such a small speaker. I think the ported box helps, but more than I expected in the lower range.

Pros: the price was great

Cons: Nothing so far

Well Made--Great product for the price

SK7 from Ramsey, MN on 9/6/2014

1984 Mercedes-Benz 300D-T
Crutchfield Customer Review (What's this?)

Works well in my 1984 Mercedes-Benz 300D-T as front speakers. Either cut or bend one corner of the metal frame and it fits nicely under the stock grills.

Pros: Frequency range sound is great. Surprisingly very clear and crisp for the cost.

Cons: Not really a Con, but they are just a little shy on the bass range. I think that is because I have a 30-yr old radio hooked up to it.

great sound from small speakers

great sound from small speakers from Springfield, MO on 8/29/2014

2006 Chevrolet Silverado 2500/3500
Crutchfield Customer Review (What's this?)


Pros: great sound.

Cons: none

Helix Blue B4X

Anonymous from Brunswick, GA on 8/20/2014

Crutchfield Customer Review (What's this?)

very efficient, very low power required, very clear, clear sound for front

Pros: very efficient, no need for a separate amp, just get a powerful receiver and flat sub woofer amp combo.


Helix blue bx4 speakers

Terry from Lancaster pa on 7/29/2014

1997 Toyota Avalon
Crutchfield Customer Review (What's this?)

Very nice speakers. Crutchfield of course had it together and made it an easy install. That is why I only use Crutchfield. Great product and sounds great.

Pros: Great product easy install

Cons: Non

Worth the money

Anonymous from Collegeville,Pa on 4/12/2014

1985 Mercedes-Benz 300D-T
Crutchfield Customer Review (What's this?)

Sound far better than the stock units

Pros: Value/ easy fit

Cons: none

HELIX Blue B4X Speakers

Jim S. from Ontario Ohio on 2/17/2014

1983 Mercedes-Benz 300D-T
Crutchfield Customer Review (What's this?)

Speakers are good quality and work as advertised.

Pros: Easy to install even without model specific adapters.

Cons: Some trimming of mounting tabs necessary for installation in Mercedes 300D.

Great low profile

DBA from David Abarr on 8/19/2013

1993 Mercedes-Benz 190E
Crutchfield Customer Review (What's this?)

Great low profile fit. Sound is ok. Not the best.

Pros: Fit

Cons: Sound

alot out of a little

Alan H from Idyllwild, Ca on 8/4/2013

1989 Mercedes-Benz 190E
Crutchfield Customer Review (What's this?)

what and amazing sound out of such a small speaker! although it was the only direct fit in the catalog, I was very impressed with the clarity and pureness of the sound.

Pros: Pure clear highs

Cons: none


Chris from Columbia, MD on 3/25/2013

2013 Chevrolet Spark
Crutchfield Customer Review (What's this?)

Way better then the stock speakers that came in my Spark. They are well worth the price.

Pros: Fits easily into my Spark, Sound awesome!

Cons: None


DanE from WA on 3/17/2013

1983 Mercedes-Benz 300D-T
Crutchfield Customer Review (What's this?)

This is about your only choice for Mercedes W123 dash speakers. I installed these in my 1983 300D with some modification to the speaker. I had to trim the metal on one corner of the speakers. These sound excellent even with the OEM Becker radio.

Pros: fit the holes in a Mercedes W123 dash

Cons: Had to trim the metal on the speakers to fit properly

Installed in a 1983 Mercedes 300TD Wagon (Dash)

Hugo T. from San Marino, CA on 12/31/2012

1983 Mercedes-Benz 300TD-T
Crutchfield Customer Review (What's this?)

So happy I found these German-made speakers that fit my 1983 Mercedes 300TD dash perfectly. For their size, they pack a punch and provide excellent bass.

Pros: Perfect fit for Mercedes W123 chassis vehicles (dash) and also rear for W123 Wagons.

Cons: None


WALT W. from HIGHLAND FALLS , N.Y, on 12/16/2012

1985 Mercedes-Benz 380SL
Crutchfield Customer Review (What's this?)




Helix Blue B4X

Anonymous from louisville on 8/23/2012

1983 Mercedes-Benz 300D-T
Crutchfield Customer Review (What's this?)

Sound awesome after install. fit perfectly but once again harness didn't address need for new connections and soldering. Had professional install (harness didn't match) but sounds great. Spent more on install that stereo and speakers.



Great sound

Milt from Knoxville on 7/12/2012

Crutchfield Customer Review (What's this?)

Drop in fit for the old Mercedes. Slound great. Rugged construction. Not made in China!

Pros: Great sound, drop in fit as promised. Not made in China!


Porsche Boxster install

2004 Porsche Boxster from Laguna Beach, Ca on 7/8/2012

2004 Porsche Boxster
Crutchfield Customer Review (What's this?)

I removed factory installed speaker then I took a dremal tool and cut the old speaker out of it's bracket and used it to remount the helix B4X speakers just break off the mounting ears on speaker an it fits right in Sound is great




Hands-on research

Features and Specs

Speaker Size
Design 2-way
Tweeter Design 1/2" Dome
Impedance (Ohms) 4
Tweeter Composition Mylar
Woofer Composition Injected Polypropylene
Woofer Surround Urethane Foam
Parts Warranty 2 Years
Labor Warranty 2 Years
Sensitivity (1W at 1 meter) 89
Sensitivity at 2.83 volts N/A
Frequency Response 100 - 22k Hz
Minimum RMS Wattage 5
Maximum RMS Wattage 25
Peak Power Handling (Watts) 75
Top-mount Depth (Inches) 1 13/16
Bottom-mount Depth (Inches) 2
Cutout Diameter or Length (inches) 3 5/8

Product Research


Woofer Materials: Each woofer cone is made of Injection-Molded Polypropylene. This process of cone molding assures a uniform cone thickness for superior linearity and clarity. It is also lighter weight and more rigid for decreased distortion and improved bass response.

Mylar Tweeters: Each speaker has a 1/2" Mylar dome tweeter for clean, accurate highs.

Magnet cover: The B 4X are shipped with a rubber magnet cover to protect the speaker. If the cover is removed the depth changes slightly:

  • Top Mount Depth: 1.622"
  • Bottom Mount Depth: 1.815"

Removable Mounting Tabs: Most 4" factory speakers use four mounting screws, however, in some vehicles, only two are used. In these cases, you can bend the unnecessary mounting tabs until they break off. The B 4X also includes the mounting clips used in some older European cars (in this case, all four mounting tabs are removed). Care should be taken handling the speaker after any tabs are removed because the broken edges may be sharp.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Q & A

Customer Q&A

2 questions already asked

There is likely a limiting factor that prevents the other speakers from fitting. For details on installation please contact an Advisor by phone or online chat. They will be able to pull up your vehicle and give you the details on what you will need for an installation in your vehicle, and let you know the reasons why the other speakers will not fit. [ Jeff  Dec 23, 2013 ]  Staff
I just bought a 2014 2LT spark. I would like to replace the speakers only. so should I buy 6 of these? and will they all fit? Thank you for answering my question Linda T [ lindataylor813  Feb 04, 2014 ]
I do show these speakers as being a good fit for both locations while retaining the factory speaker grilles. [ Jeff  Dec 11, 2013 ]  Staff