JL Audio Factory: A Visit to the Mothership | Bob Katz

JL Audio factory
JL Factory Main Building

Before Covid changed the world, my wife Mary and I were lucky to visit the bustling JL Audio Factory in Miramar, Florida, where dedicated technicians updated my two JL Audio Fathom F-112 subwoofers with the latest electronics and drivers. We were also privileged to get a courteous, full range factory tour given by Randy Wagner, Technical Support Specialist, and Stephen Turrisi, Senior Director of Training and Technical Services.

The JL Audio main building is an impressive four city blocks long! There is also a second building (which we did not visit) and soon a third building in the same area. While Covid may be slowing JL Audio down, it has not curtailed their bustling enterprise, with over 600 U.S. employees and facilities in Miramar, Florida, Portland, Oregon and Phoenix, Arizona.

Words by Bob Katz, Photos by Mary Kent

Not much has been said in the audio press about how our home-grown manufacturers are suffering from punitive tariffs which are still in place in the current presidential administration. They cover not only raw materials, but also component parts and finished goods imported from China. Manville Smith, JL Audio Director of Marketing, informed me that there is no word as to whether these tariffs will be rolled back or phased out. Our previous president insisted that the cost of tariffs would be borne by China and other exporters but the data shows that it is Americans who are paying the costs — since these taxes are paid by American businesses, and costs are subsequently passed on to consumers.

bob katz randy wagner shane dalley
Bob Katz, Randy Wagner – Technical Support Specialist and Shane Dalley preparing for action

In fact, American manufacturers are particularly hard hit, because manufacturers in other countries can import materials and components from China without paying excess tariffs. They can then build products using these parts, enjoying a competitive advantage against U.S. manufacturers. The pressure is on and so we audiophiles can only hope the situation will relent or else “made in America” may become a thing of the past when it comes to audio gear.

Jl Audio factory update
Shane Dalley brings Bob’s woofers into the JL Factory for an update

But let’s look at the bright side. JL Audio is still here and building quality product, as we shall see. Mary and I arrived from Orlando with those heavy woofers in the back of our Subaru Outback and JL took it from there.

Bob Katz and Randy Wagner
Bob and Technical Support specialist Randy Wagner planning our factory tour

Once in the main office of the expansive main building, Technical Support specialist Randy Wagner gave me a preview of my factory tour and the woofer update.

My woofers had been well-cared for but were fairly old at that point and deserved some loving care. JL Audio was prepared to update the amplifier as well as two of their custom-built drivers, which are constructed right there at the factory from component parts and materials.

JL Audio factory floor
Two rows of heavy JL inventory, all placed on pallets

On the factory floor we found rows and rows of pallet racks with an impressive amount of JL Audio inventory.

jl audio tour with bob katz
Bob, Randy and Stephen Turrisi, Director of Training

Randy then introduced me to Stephen Turrisi, JL Audio Director of Training. Which one of us has the best Florida tan?

Jl Audio Gotham

Hitting the JL Audio Factory Floor

From there we moved to the actual factory floor, where subwoofers are not the only products being manufactured. JL Audio also makes full range domestic systems as well as marine (boat) and car systems. Photo above shows one of the many prepping and polishing steps required to achieve the JL Gotham woofer’s deep gloss finish.


Around the corner we saw racks and racks of automotive speaker enclosures, ready for finishing.

jl audio factory

Some of JL’s components are made from fiberglass, and others from MDF. In the photo above, a worker clamps a mold shut in preparation for injecting resin to make a fiberglass part.

fiberglass mold

JL pays incomparable attention to detail. My woofers had been packed with white gloves so I would not spoil the glossy black finish. Inspection is a regular part of the creative process. Above, a worker inspects a fiberglass mold prior to putting it on the production line.

Jl Audio mobile speakers

Here a mold used to make fiberglass loudspeaker enclosures for mobile audio undergoes maintenance.

CNC machine

JL employs the latest electronic equipment to ensure quality and precision of its parts. In the above photo, a technician operates a complex CNC mill to precisely cut speaker openings into fiberglass parts.

JL Audio Gotham subwoofer

Building a JL Audio Gotham subwoofer

The Gotham subwoofer is a work of art, containing two 13.5 inch subs in a black gloss finish. Two woofers not only provide increased power and SPL, but also, by distributing room modes, the frequency response is improved over that of a single woofer. Many steps are required to bring a Gotham to fruition. Above, a technician sands the finish to prepare it for painting.

JL Gotham subwoofer

Above, a Gotham enclosure begins with thick fiberglass matting and is precisely cut and laid into a mold cavity.

CNC brace for JL sub.

In the photo above, one of the many CNC-cut braces that goes inside a JL Audio in-wall subwoofer enclosure.

Jl Audio CNC
Parts for many enclosures can be fabricated from a single sheet of CNC-cut MDF.

The output of one large sheet of CNC-cut MDF yields parts for many enclosures. The set above is destined for mobile audio use.


Jl Audio assembly line

Above, mobile audio enclosures are prepared for final assembly.

JL Audio and Bob Katz

A huge number of wood parts are cut every day to be used in a wide range of JL Audio’s mobile audio and home audio products.

Front skin of an in-wall home theater enclosure

JL home subwoofers are often hidden inside walls of home theaters. In this photo, Stephen Turrisi shows off the front skin of a JL Audio in-wall, home subwoofer enclosure. These systems use thin materials but achieve excellent rigidity and freedom from vibration thanks to an engineered architecture of braces and supports.

JL Audio factory.

On this rack, Stealthbox® mobile audio subwoofers are awaiting speaker installation and final inspection before being shipped to customers.

Stephen of JL Audio
Stephen shows off a low-profile mobile audio subwoofer.

This photo shows off one of JL Audio’s many low-profile woofers. This one is destined for mobile audio, but a similar design is used in their in-wall home subwoofers.

JL Audio fiberglass waveguides
Fresh off the mold, a fiberglass waveguide used in high-end marine audio systems.

JL Audio and the Art of Boatbuilding

Diversity is what keeps JL going through business cycles. Audiophiles may not be aware of the company’s thriving boatbuilder segment. Here is a fiberglass waveguide, freshly pulled from its mold. It’s used in high-end marine audio systems.

Building speaker cone assemblies.

In the next section of the factory, marine loudspeaker drivers are created. In the above photo, cone assemblies for marine loudspeakers are being inspected and prepared for assembly.

JL Audio assembly

Not many of you may realize that JL is a complete operation, manufacturing all loudspeakers from scratch! They even fabricate a lot of their tools. In this photo, a worker centers the coil and spider on a machined fixture to precisely align them prior to entering a chamber where glues and activators are applied.

Loudspeaker motors from JL.

On this table, hundreds of loudspeaker motors are staged for final assembly.

Motor Assembly Department of JL Audio

In the motor assembly department, a worker assembles t-yokes, magnets and top-plates on a carousel which allows the correct adhesive curing time.

Fathom F212 subwoofer assembly

The above photo shows final assembly of a Fathom F212. One technician is responsible for the entire assembly and is equipped with a wide range of precision tools and a motorized lift.

The intricate construction of a JL woofer

These two intricate drivers are going into my updated Fathom F112 subwoofers. The unique surround permits excursions up to 3.7” without overdriving, producing far more output without distortion than competing 12” subs. JL builds these massive drivers about 100 feet from this final assembly area.

Bench test for JL Audio.
Bench testing Fathom subwoofer amplifiers

In the lab next to the assembly area, the electronics package of Fathoms is bench-tested as a complete system, using JL Audio’s proprietary ATE equipment.

Bob Katz and his subwoofer
Bob admires his updated subwoofer

Going Back Home

After update, my 117 pound woofers are ready to return home. JL was kind enough to leave my labels indicating switch positions and levels that I use.

JL Audio
Bob’s Studio A: JL Fathom F112 subwoofers next to Dynaudio Evidence M5P mains.

Finally, my updated woofers return home to Studio A, my mastering room.

[In the words of Scot Hull, our publisher, “Bob Katz is a mastering engineer with an impressively long CV.” Bob will be contributing occasional columns to PTA in the future–Ed.]