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Focal K2 Power™ 40 KX

16" subwoofer with dual 2-ohm voice coils

1 Review | 1 question - 1 answer

Item # 09140KX

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Our take on the Focal K2 Power™ 40 KX

This sub's name gets straight to the point — the Focal K2 Power subwoofer delivers hard-hitting low end that combines realistic reproduction with competition-level sound pressure. Precision engineering and hand-assembled construction make this sub a sound choice for a high-performance bass system.

This sub's name gets straight to the point — the Focal K2 Power subwoofer delivers hard-hitting low end that combines realistic reproduction with competition-level sound pressure. Precision engineering and hand-assembled construction make this sub a sound choice for a high-performance bass system.

Powerful magnet
A massive multi-element magnet provides the backbone for the sub's powerful reputation — its circular array provides a uniform field across the entire width of the sub, driving the motor assembly with unerring precision. Focal anchors the K2 Power sub with a rugged zamak zinc alloy basket for dependable performance that won't get bent out of shape by your music.

3-layer cone
At the top end of the sub, a butyl rubber surround maintains control of the cone, even during deep excursion. Focal's unique composite sandwich cone employs a structural foam central core coated with layers of Kevlar on the front and back sides. The three layers together form an incredibly rigid yet lightweight membrane for high-quality sound reproduction with the added emphasis of thunderous sound pressure.

Assembled and inspected by hand
You can feed the K2 Power 40 KX 16" subwoofer up to 500 watts RMS without fear. This sub produces bass that's highly accurate and plenty forceful, and its dual 2-ohm voice coils provide plenty of wiring options for your system. Focal assembles each sub by hand and rigorously inspects them for any flaws to ensure your investment performs to the high sound standards they've set.

Note: If you are wiring this DVC sub for lower impedance, make sure that your amp is compatible.

To drive this single subwoofer, we recommend a mono amplifier rated between 375 and 750 watts RMS at 4 ohms. For more information, please refer to our article on How to Match Subwoofers and Amplifiers.

Priced per speaker

This is the best 15-16" subwoofer I've ever used on a SQ based audio system using a 40 L Sealed box

Johney, Montvale, NJ

What's in the Box:

  • One 16" Dual 2-ohm voice coil woofer
  • 8 Hex-head mounting bolts
  • 8 Spiked T-Nuts
  • Self-adhesive foam gasket
  • Cloth cover (for magnet)
  • Manual (English/ French)
  • Serial number card
  • FOCAL logo sticker

Product Highlights:

  • 16" subwoofer with dual 2-ohm voice coils
  • Kevlar/foam sandwich cone with butyl rubber surround
  • multiferrite magnet for precise motor structure linearity
  • zamak (zinc alloy) basket
  • power range: 50-500 watts RMS (250 watts per voice coil)
  • peak power handling: 1,000 watts
  • frequency response: 25-1,000 Hz
  • sensitivity: 86.26 dB
  • top-mount depth: 7-7/16"
  • sealed box volume: 1.41-2.82 cubic feet
  • warranty: 1 year
  • Our 60-day money-back guarantee

Focal K2 Power™ 40 KX Reviews

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Hands-on research

Product Research

Enclosure Compatibility


K2 Composite Sandwich Membrane/Cone: The FOCAL K2 Power 40KX features a composite sandwich membrane/cone comprised of a foam layer, sandwiched between two Kevlar layers. The result is a material structure that is rigid, yet light weight, and allows fast bass response without distortion.

NBR Surround: The 40KX features a long-throw NBR (Nitrile Butyl Rubber) surround for long excursion, deep bass (25-1000 Hz), and added durability to promote long life.

Copper Voice Coil: The dual 2-ohm voice coils are 4 layer, 2.55" diameter, edge-wound copper on an aluminum former, resulting in high power handling, low distortion, and impedance flexibility to allow an optimized connection to the amplifier.

Dual 2-ohm Voice Coils: This woofer features two 2-ohm voice coils that offer wiring flexibility. When the voice coils are wired in parallel, the woofer presents a 1-ohm load. When the voice coils are wired in series, the woofer presents a 4-ohm load.

High-Performance Spider: The 40KX features a high-performance spider with the tinsel leads sandwiched between the two layers to eliminate wire fatigue.

Multi-Ferrite Magnets: The 40KX utilizes six triple-stacked Ferrite magnets (18 total) to create a powerful magnetic field to help suppress compression and give better power handling. This Multi-Ferrite motor assembly allows for greater efficiency (92.5 dB), higher power handling capabilities, and natural cooling of the woofer's voice coil.

Die Cast Zamak Basket: The vented die-cast Zamak basket is rigid, non-magnetic, and non-resonant. The vented basket provides a self-regulated coil cooling system, allowing air to flow freely to prevent heat build-up.

Spring-Posts: The woofer features two sets of nickel-plated spring-post speaker terminals that will accept pin connectors, dual and single banana plugs, and bare wire up to 8-gauge.

Removable Cloth Cover: The K2 Power 40KX woofer comes with a cloth cover to protect the magnet from scratches or smudging during transport, handling, and installation. The cloth cover should be removed when the woofer is installed.

Enclosure Compatibility

Sealed Box Volume: The 40KX is designed to be installed in a sealed box with a volume between 1.4 ft³ and 2.82 ft³. FOCAL highlights three specific sealed enclosures in the manual:

  • 1.41 ft³: Fast and tight bass, -3dB frequency of 41 Hz
  • 2.19 ft³: Punchy and dynamic bass, -3dB frequency of 37 Hz
  • 2.82 ft³: Deep and articulate bass, -3dB frequency of 36 Hz

Our Product Research Team

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1 question already asked

Thanks for your question. For information on selecting the best amp for your subs I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They will be able to help determine the differences between the amp models and help you make the best choice for your system. [ Kenny  Apr 06, 2016 ]  Staff