Item# L8400P



600-watt, 12" powered subwoofer

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JBL® is know the world over for providing movie theaters and arenas with the best, most accurate sound. But you don’t have to wander far and wide to get that same, famous sound right in your own home. The JBL L8400P is the subwoofer for you if you’re looking to hear the realism and precision from today’s high-definition formats. Its driver is made of patented PolyPlas™ material, which is strong and lightweight, so it reproduces bass effortlessly and with maximum impact. The driver itself, a 12-inch (300-millimeter) woofer cone, sits in a cast-aluminum frame, which provides a non-flexing structure and a rigid foundation to keep the bass accurate, distortion-free and uncolored. In addition, the L8400P uses a low-diffraction IsoPower™ baffle and ultra-rigid enclosure to ensure that unwanted resonances don’t affect the sound, plus a Symmetrical Field Geometry™ motor assembly to maintain uniform magnetic force. But the subwoofer’s muscle is its incredibly powerful Class D amplifier, which can produce 600 watts continuous power and 1200 watts peak power – enough for even the most demanding action movies or live-concert DVDs. All of that power can make ordinary drivers overheat, but the JBL L8400P’s driver is far from ordinary. It uses a specially designed Heatscape™ motor structure, which whisks away dangerous, sound-distorting heat. You’ll hear deep, tight bass – as low as 22Hz – that’ll literally shake the floor but remain accurate enough to reveal all the subtleties in your favorite music and movies. And if that’s not enough, this subwoofer is beautiful and available in three finishes – black ash, beech or cherry – that are sure to complement any décor.

What's in the box?

  • (1) L8400P 12", 600-watt RMS (1200-watt peak), high-performance powered subwoofer
  • (1) Owner's Manual

Our proprietary PolyPlas material, a polymer-coated cellulose fiber used to coat low-frequency cones and drivers, combines strength with light weight, so it reproduces bass effortlessly and with maximum impact. The L8400P’s 12-inch (300-millimeter) PolyPlas cone offers enough impact to rock your bones.

Cast aluminum is durable and strong, and resists corrosion, heat and magnetism. A speaker’s frame supports the driver’s cone, diaphragm and other parts. The L8400P’s cast-aluminum woofer frame is tough enough to protect the low-frequency driver so that it can reproduce your music in high fidelity.

Heat can distort a speaker’s sound and lower its output and power handling. Fortunately, the L8400P includes our proprietary Heatscape motor structure, which removes heat. As a result, the L8400P operates efficiently and reproduces sound accurately.

A speaker’s baffle and enclosure should keep outside noises from entering the speaker and interfering with the sound that the speaker generates. JBL engineers have built the L8400P with a special IsoPower baffle and an exceptionally stiff, tough enclosure to keep your audio safely protected on its way to your ears.

Sheer power. That’s what the L8400P’s amplifier offers: 600 watts RMS and 1200 watts at peak. So play your music and movies as loud as you want. The L8400P’s amp can give you high volume without the slightest strain.

Enclosure Type
Black Ash
Studio L
Frequency Response
22Hz – Low-pass crossover frequency
Crossover Frequencies
50Hz – 150Hz, Continuously adjustable
Amplifier Power (Peak)
Amplifier Power (RMS)
Low-Frequency Transducer
12" (300mm) PolyPlasTM cone with rubber surround and cast-aluminum chassis; HeatScapeTM motor structure; Symmetrical Field GeometryTM (SFGTM); oversized fiberglass voice coil; magnetic shorting ring

The latest owner's manuals, quick start guides, and documents.

1 Year Electronics / 5 Years Loudspeaker Warranty

Products purchased online or from an authorized local retailer and under warranty may qualify for an exchange with a valid receipt.

Purchases made from an unauthorized dealer will not be eligible for exchange.

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Call us: 1.800.336.4525

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L8400P is rated 5.0 out of 5 by 3.
Rated 5 out of 5 by from Going strong over six years Bought this monster back in May of 2007, and ever since have been enjoying movies and music like they really should be heard - and felt :) I also have JBL's Studio L880 towers, which produce pretty strong bass, but the L8400P goes beyond them, with even deeper reproduction, and more "oomph". The only thing I would have preferred in this sub would be a different design for the feet. But that's very minor, and a personal preference. It's well built, looks good, and sounds great.
Date published: 2013-12-19
Rated 5 out of 5 by from Two years of pure delight Bought in Lima, Perú, this incredible subwoofer has delivered thousands of hours of joy, no matter you use it for music or films. Although I purchased a 110 V model, with a good transformer it works finely and matches perfectly a Denon AVR 4520. Highly recommended.
Date published: 2013-10-09
Rated 5 out of 5 by from BASS with capital letters!! Great sub woofer next to my other Studio L speakers. The Stuido L890 goed deep, but the L8400 even deeper!
Date published: 2012-08-12
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