Touring the JL Audio Factory

JL Audio is known for its high-quality audio products manufactured entirely in the United States. At the huge Miramar, Fla. facility, the company utilizes state of the art tools and technology—including an on-site machine shop—to make everything in-house.

WORDS BY JOEY KNAPP

Back in September I was in South Florida, and reached out to Stephen Turrisi (Director of Training and Technical Services for JL Audio) to see if I could go on a tour of their facility. Regular readers of Tech Today may remember that I had a chance to tour the Focal factory a few years ago, so I was eager to see what was happening at JL Audio.

I have known Steve for many years and it seems fitting for a man so obsessed with magnets to be working for one of the top audio manufacturers. I was thankful that he was able to spend time with me since my trip down was arranged at the last minute. Steve was quick to note that normally their productions teams are not scheduled to work on Fridays (the day of my visit), but because of the incredible, increasing demand for products, the company added another shift and overtime to catch up with the backlog of orders. This was good for me since most of the areas were up and running.

We started off in the main office. JL Audio has several locations, but the Miramar, Fla. office is the main headquarters. They also have locations in Phoenix and Portland, plus some smaller offices scattered around the country and around the globe. After a quick visit to the OEM

The heart of the JL Audio shipping department.

marine division, customer service and some of the sales and finance offices, we moved into a huge manufacturing facility.

Our first stop was the shipping department. Steve explained that shipping was as close as possible to the middle of the long, rectangular building. Then, on either side, manufacturing could funnel to this centralized location for shipment. The location of the finished goods within the shipping area would often change to account for changes in sales rates, he said. They like to keep the faster moving products as close to the actual shipping locations as possible for efficiency. This was the first of many areas where it was apparent that JL Audio focuses on efficiency and rapid growth.

We headed west toward the fiberglass and woodshop production areas. We stopped along the way and I noticed how many of the offices were elevated and on

wheels. Steve explained that they built them on-site and put them on wheels to allow for them to be moved to other areas as they modify the flow of production to accommodate more volume or improve efficiency. Apparently, they can build great audio gear and their own offices and furniture, too.

A Look at Stealthbox Fabrication

The west end of the building houses the fiberglass and woodshop departments. The JL Audio Stealthboxes came out a few years after the company was founded in 1975. I was surprised to see how the manufacturing process is very labor-intensive. They use a system called “Resin Transfer Molding” to carefully control the thickness and consistency of the Stealthbox. They start with a layer of fiberglass inside the mold, and use

a vacuum at one point of the mold to “inject” resin and hardener into another point. The vacuum pulls the resin/hardener mixture through the mold to ensure that air pockets don’t form. Most Stealthboxes have two parts. Once each half is formed, they are bonded using what Steve called “goop.” To me it looked like a mixture of chopped strands of fiberglass, Cabosil and resin. Once the two parts are bonded, they trim the edges, fill in any areas and sand it down. Then, they use a pneumatic tool to set rivet nuts into the enclosure, which is much nicer than the hand version I use!

From there, the enclosure is put into a “sub-assembly inventory” and labeled as a “naked Stealthbox.” The “naked” part references to the final finishing (carpeting and paint) to complete the product. This finishing did not happen during my visit, but I did see the shelves of naked

JL Audio uses prelayered fiberglass mat for consistent thickness.

Stealthbox molds are stored on the shelving units right next to the fiberglass mold area.

Stealthboxes, as well as racks with finished versions awaiting inspection and packaging.

Enclosure Construction

In a huge back corner next to the fiberglass department is “The Woodshop” area. This cavernous area is where they cut wood for enclosures and various other things, like the baffle the W7s are attached to when they are sent out. There were a number of CNC routers that were running and making precision cuts and grooves in sheets of MDF. Despite several machines all cutting wood, it was remarkably quiet. Steve told me that they had recently added a number of sound panels on the walls and ceiling to absorb and break up reflections to help reduce the noise. Pretty cool!

In front of a couple of routers, there were pallets of cut wood. Steve brought me over to one pallet that would later be used to build the the eight-inch ported MicroSub enclosure. I was really surprised that such a little enclosure was built with 12 pieces of wood. He turned over the front piece of the enclosure to reveal the intricate channels that were cut into the wood to accommodate the port and internal braces (yes, there are braces inside that tiny box!). To minimize the depth of the overall package (just a hair over five inches), JL Audio uses ½-inch MDF instead of the more traditional ¾-inch. Before anyone clamors about this, take a look at the photos of how the bracing is done on this marvel. Instead of just using a thicker wood, they engineered the bracing to make the enclosure more rigid.

As a side note, this same engineering was applied to their home audio in-wall subwoofer systems. For those unaware, JL Audio has a couple of really cool solutions in their home audio product lineup that are designed to fit inside of a standard wall cavity (2 by 4 or 2 by 6 construction). A typical stud bay for 2 by 4 construction only has about 3.5 inches to work with, so in addition to using their thin woofer designs (like the 13TW5 and the new in-wall specific eight-inch driver), they reduce the enclosure thickness by using thin birch plywood and abundant bracing

The sound abatement treatments for the wood shop area are visible on the walls and ceiling.

throughout the enclosures. In addition to the strength improvement, these braces also help to break up resonances.

We left the CNC-router area and headed over to the section where they assemble these enclosures. In an odd twist, they don’t even build these enclosures the “normal” way. Ordinarily you would cut the wood, assemble the enclosure and then cover it in carpet. Not JL Audio. Their engineers came up with a pretty unique way of assembling what they call “wrap sets.” A wrap set is a group of wood panels that are glued to a pre-cut piece of carpet with rigid backing. I watched as they built some of those MicroSubs. These enclosures are comprised of two wrap sets, braces and end pieces. In each of the channels cut by the CNC, they apply copious amounts of glue and place the other wood parts into those channels to wrap the enclosure. Each of the outer panels perfectly lines up inside the grooves and the glue holds together all of the interior panels and seals up any air gaps. It’s a great concept.

In-House Machine Shop

On the way to the east end of the building (where the loudspeakers and home audio systems are assembled) we visited the JL Audio Machine Shop. As an engineering-based company, JL Audio has plenty of hands on-deck to try to solve any problems that may come up. This is not only evident in their products, but also in their assembly process. Steve said that in the early days, JL Audio relied upon external machine shops to build prototype parts for speakers and production lines. Sometimes the lead times for these items was weeks or months.

As the company grew, they cut these lead times down by investing in their own in-house machine shop. Seems logical, but it comes at a pretty hefty cost—these machines are not cheap! I was able to sneak a peek and snapped a photo of the shop through the window on the door. I am not familiar with that level of machinery, but in layman’s terms, they had a bunch of big ones! I later saw racks and racks of parts that came from the machine shop being used in speaker production. These parts and many aspects of the production lines themselves were designed and built right there at JL Audio. The machine shop is a vital part of what they do.

The wrap sets are glued together before heading to assembly.

Guillotines and Magnetizers

Just outside of the home products assembly area and just before the loudspeaker production site, I visited an intriguing spot. Somewhat hidden by shelves full of speakers and subwoofers, I found a room with a contraption that resembled a medieval guillotine. Steve said it was where they brought people who shared secret photos. Okay, not really. It was actually a device they constructed to perform “drop tests” on various products.

It looked like a combination of electrical and pneumatic contraptions that would raise and release a fixture that would hold a speaker. At the bottom was a “stop point” that would stop the fixture and exert enormous g-forces on the frame (and other parts) of the speaker. They would document the height and the amount of g-force measured and track any failures they encountered. Sounds like the loudspeaker equivalent to a crash-test dummy.

Once inside of the loudspeaker assembly area, Steve showed me where they work on motor assemblies (the magnet and its surrounding metal parts). A pallet of motors sat waiting next to a refrigerator-sized device with a strange chamber attached to it by a huge cable. The contraption turned out to be a magnetizer and the motors had not yet been charged. Steve showed me a tool called a “go/ no-go” gauge. It had a red band on one side and a green band on the other. On each end was a small rod. The rod on the green side was slightly smaller in diameter than the red side. This was used to make sure the gap (the area that the voice coil will hang inside the speaker) would be the proper size. If the green side fit in and could travel all the way around the gap, that meant it was good. They also check to make sure it isn’t too wide by attempting to put the red side in. It

The dual-ended go/no-go gauge is used to check voice coil gaps.

Each motor assembly is checked for proper clearance.

The MX770 cone and surround assembly awaits construction.

The speaker tinsel leads are precisely soldered to the terminals.

shouldn’t fit at any point. JL Audio tests every single motor before they drop it into the magnetizer.

Marine Speaker Assembly

The production area was surprisingly busy considering they don’t normally work on Fridays. Marine products were everywhere. I got to see the MX770 marine coaxial speakers being assembled. My journey with the MX770 construction started with the cone/coil/spider assembly. These parts had already been glued together and were ready for merger with the basket. From what I could see on the production line, the glue, the spider and the surround to the frame were applied by an automated process at the beginning of a four-person assembly line. A machine applied the glue, and then the parts were added into place while a weight applied even pressure as the glue set.

Once joined, the speaker moved to a station where they connected the tinsel (lead) wires to the terminals. Once they were soldered in place, they applied another adhesive to seal everything.

The assembly station for the W3 woofers.

They used a spray-type accelerant in a number of areas to speed up the cure time of the adhesives. For the final step of production, they added the grille, which already included a tweeter. From there, the speaker goes through several quality assurance tests before being packaged and shipped.

W3 Subwoofer Assembly

One of the production lines was configured for W3v3 subwoofer assembly. Even though it wasn’t running that day, I could see several parts on the line, all in different stages of assembly. At the front of the line sat some sub-assemblies consisting of the spider, voice coil and terminals all held together by plastic components. Steve explained that these “lower assemblies” were designed after monitoring speaker assembly and warranty returns over the years. The center area, located around the voice coil, was the VRC (Vented Reinforcement Collar)— one JL Audio’s earlier patents from 1995, intended to improve the reliability of the speaker by providing a larger contact area for the glues to hold.

It also provides better cooling for the coil by positioning vent holes just above the voice coil. He demonstrated how

the lead wires were carefully controlled and how the entire assembly lays into the frame using a special fixture to keep everything aligned properly (yes, it was made in the machine shop!). I got to see how the FCAM (Floating Cone Attachment Method) worked; it is essentially a large channel located in the middle of the speaker assembly, just above the voice coil area. The channel allows the cone to slide in after it is filled with glue. Any variations in parts and assembly can be “absorbed” by allowing the cone to “float” to the center position without tugging one way or the other.

The speakers then move down the assembly line on aluminum plates on wheels, which was also made in the machine shop. Conveyor-belt manufacturing like this is not new, but it was interesting to see in person.

Parting Thoughts on the Tour

First and foremost, it was impressive to see JL Audio’s commitment to build as much as they can in the USA. Steve told me that Lucio Proni, the company founder and CEO, is very committed to supporting the local economy and building as much product on-site as they possibly can. He’s doing just that, judging

by the huge number of employees I saw— and this had been a slow day! It is more expensive to manufacture in the United States, so the team at JL Audio has had to work hard to maximize their efficiency in order to stay competitive against companies that source cheaper labor. Somehow I feel this is a challenge they love.

There were many places in the facility that Steve showed me which I haven’t described here, and many rows of shelving filled with parts and packaged products. The few photos I have shared do nothing to portray the enormous size of the JL Audio facility. It is huge. Despite the size, Steve seemed to know most of the people we saw on the tour. I was the only person on the tour, so it hadn’t been a staged “open public tour day.” Steve knew most of the employees by name. I think that says a lot about the company. Often, we stopped at a station, talked about history, how things have come so far and how long they had worked together. Many of the workers had been with JL Audio for quite a while. It’s clear they care about what they build and who builds it—as well as their customers and end-users.