JL Audio C2-400X Review – All Round Performance at a Reasonable Price

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The JL Audio C2-400X is a great 4-inch speaker for smaller vehicles, with amazing high and mid-range frequency. It can struggle with lower frequencies, so is best partnered with a subwoofer to get the most out of your system. May feel a little quiet to some.


  • Very affordable speaker for the price
  • Great “all-round” sound production
  • Includes adapters for fitting a variety of different places


  • Can struggle with lower frequencies
  • Not as loud as alternative models
  • Not suitable for larger or open-top vehicles

The JL Audio C2-400X speaker is impressive; bringing together two areas where JL have excelled—tweeters and woofers. For a very reasonable price, the C2-400X acts as a highly efficient middle ground between tweeter highs and woofer lows, retaining a smooth mid-range at the same time.

The combination of quality high and mid-frequency delivery makes it a great speaker for rounding out the sound in your vehicle. It is also a great speaker for getting high fidelity sound on a budget if you can’t afford a full speaker system for your car.

The volume may feel a little low to some, making it more suited to smaller vehicles, and the bass production isn’t the best. But these are reliable speakers at a reasonable price, especially if combined with a subwoofer.


The C2-400X is a 4″ speaker with a rugged build quality and a stylish exterior. It comes with a grill for custom installations, as well as a set of adapter plates, allowing you to install these 4″ speakers in a 6″x9″ hole.

The speaker itself features polypropylene cones with, and rubber surrounds that are designed to handle plenty of power without distorting.

It features a 3/4″ silk dome tweeter to handle high frequencies without sounding harsh. This high-frequency delivery adds a layer of clarity to your sound that other speakers may lack. Meanwhile, built-in crossovers work to prevent the woofers from reproducing frequencies that they were not designed to.

The combined effect gives you full-bodied tones that capture all of the detail of your audio without completely losing the lows that allow you to feel what you are listening to.

The relatively shallow depth and low weight of the speakers make them very versatile when it comes to placement in smaller places, and the included adapter plates make them just as suitable in spots designed for more substantial speakers. These attributes, combined with the easy to access connection terminals, which have a decent amount of clearance from the speaker itself, make the C2-400X a straightforward speaker to install.

JL Audio has made use of high-quality components in the C2-400X to ensure not only a great sound but also a long operational life when compared to speakers that use cheaper parts. Stamped steel frames provide strength and durability to the speaker that belies its small size.


  • Max Power Output – 105 Watts
  • RMS Power Output – 35 Watts
  • Frequency Response – 71 Hz – 22 KHz ± 3 dB
  • Mounting Depth – 1.81″


Last update on 2024-05-18 / Affiliate links / *Image Disclaimer: We use images/data from Amazon Product Advertising API solely on products that link to Amazon. On products with the "Price at Crutchfield" button, we use images/data from Crutchfield.com as per the partnership deal.

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