October 1999

Thiel Audio Factory Tour
by Marc Mickelson

Factory

My tour of Thiel’s manufacturing facilities was led by Walter Kling, Thiel’s manufacturing director, and endeavored to follow the speakers as they made their way through the factory. I saw stacks and stacks of MDF and veneer for cabinets, piles of materials for the manufacture of drivers, electronic components by the bin, and ultimately any number of Thiel speakers in many different finishes and varying degrees of completion. Along the way I was shown every nook and cranny at Thiel, and so I saw everything -- and took more pictures than I could use. You will, however, see the bulk of them.

Manufacturing at Thiel revolves around the CNC (Computer Numeric Controlled) machines that shape the MDF into speaker cabinets. In Thiel's past, the CNCs could take up to five days to retool for a new model, making the manufacture of large batches of speakers a definite advantage. And Thiel used to produce large runs -- 200 speakers at a time. However, customers would then have to wait if, for example, they ordered pairs of CS3.6es and the factory wasn’t making them and there were none in stock in the desired finishes. So Thiel undertook a massive task: change the way they produced their speakers so customers could be served more promptly. This required not only setting reasonable goals but also re-evaluating the various processes by which the company produced speakers.

The reworking of production took an entire year and, as I could discern, a great deal of planning. Thiel eventually developed the system they currently follow: much faster CNC setup -- two hours on average -- and one-day runs of approximately 20 pairs of speakers. Now when dealers place orders, even for models with custom finishes, they are quoted ship dates immediately, which allows them to tell customers when they can expect their speakers. For the most part, production marches in lock step with demand, which means quicker order fulfillment and lower overhead. These translate into savings for customers.

The speakers begin as large sheets of MDF that are cut to rough size based on the speaker model being created. Pieces for the cabinet are veneered on both sides, while those for the baffle (if the model uses MDF for the baffle; some baffles are made of a mineral/fiber composite material) are glued directly together to create the desired thickness. It was obvious to me that picking and cutting veneer is an art, and this is compounded by the fact that all veneer is book matched per pair of speakers, so the craftsman has to keep the pieces of veneer stacked in an orderly fashion so when they are glued onto the cabinets, the matching is kept intact. In some cases, smaller pieces of veneer have to be joined together to make larger ones, and this is done on a special machine so that the seams are unnoticeable. It works too. I spent a few minutes examining a large CS7.2 cabinet and couldn’t find a seam.

Thiel has racks and racks of veneer, 40 or more different high-contrast veneers in stock at any one time. And if they don’t have it when an order is placed, they’ll find it. They also can create custom finishes to match any color or existing woodwork. I was able to see an original sample they were trying to match and their facsimiles, both of which I mistook for the original because of the more natural grain pattern. Yes, they can even simulate wood grain.

After the veneer is cut, it is sent along with the panels over to be glued and pressed. This is a two-man job, one running the boards through the gluing machine and the other removing them, affixing the veneer, and then stacking them in sequence. After they are glued and stacked, the MDF/veneer sandwiches are put into a large press, where a precise amount of pressure is exerted for a calculated amount of time. Any more or less pressure and time could cause abnormalities.

After the pressed panels have dried, they are sent to be sanded. As Walter Kling explained to me, Thiel thought this seemed counter-intuitive -- you mill the pieces and then sand -- but purchasing a special sander that would properly handle the various angles on each milled piece would cost a whopping $200,000. So they tried it the other way around, sanding then milling, and it worked very well, removing many of the burrs at the edges of the pieces that might cause chipping later.

Thiel currently operates two of the large and very expensive CNC machines, with a third one coming online very soon. All of the machines are encased in purpose-built housings to cut down on noise and the amount of dust that spreads throughout the factory. The CNCs not only cut and shape the side panels, but also the baffles, which often require sculpting. With all of the work they do, the heads on the CNCs have to be changed daily so the cuts and shaping are precise and as free of burrs and scuffs as possible. One of the important jobs the CNC operators at Thiel perform is taking measurements after milling to make sure that the pieces are precise and the CNCs are cutting and shaping perfectly.

Once the pieces are sanded and milled, they are stacked precisely on carts to maintain the matching of the grain and wheeled over to the build area, where they are glued and assembled into cabinets. The workers at Thiel are rewarded for knowing how to perform more than one step in the process, and the day I visited, a fellow who started the day painting baffles began a build of Thiel’s small SCS3 speakers. As was explained to me, this not only made it possible for some people to fill in for others but also know more about the whole process and be able to bring different disciplines to bear on each individual step. Interestingly, small notches are cut into the panels at the joints so that builders need only line up the notches to assemble a speaker. There are, of course, many fine points to assembling the speakers, from using the right amount of glue to making sure the joints are perfectly aligned, but having the notches as a guide is smart.

After the cabinets are assembled and while the glue is drying, the baffles are painted and allowed to dry. While this is happening, grilles are assembled for the speakers. In this area, I was able to see one of the special Thiel-built machines for precisely bending pieces of aluminum for the grille frames of certain speaker models. These grilles are not stamped out but actually assembled -- pieces of aluminum are bent and then affixed to each other with self-locking pins, after which the grille cloth is stretched over them. Doing this in house, when it could easily be sub-contracted, saves money and allows Thiel to use the expertise learned to make grilles for new models as the speakers are introduced. Why not do it yourself?

After the cabinets are dry, the drivers and crossover are installed and connected. Thiel’s crossovers are assembled by hand and tested via computer and a piece of software that Jim Thiel wrote. Drivers are assembled in a separate area and tested on the spot. So many of the devices for manufacturing the drivers are custom built by Thiel, which gave me even greater appreciation for the fact that they create their own drivers to begin with. Some of these also run via software that’s programmed in house.

After the speakers are assembled, testing and packing are the final steps. Each speaker is put through a number of tests in Thiel’s anechoic chamber and then subjected to a listening test that a technician performs after the speaker passes the anechoic tests. As with the testing of crossovers, the anechoic tests are run via computer and software that Jim Thiel created. Thiel’s anechoic chamber resembles a fallout shelter from the outside. The purpose-built conveyor belt brings the speaker into the chamber for testing, then rolls it back out. Because of the angles and weight of Thiel speakers, packing is custom made. Here again Thiel has produced its own machines, in this case a series of packing "cutters" that actually shape the foam blocks like a hot knife through butter.

Thiel prides itself on responding to orders quickly, and they maintain a back stock of speakers so they can keep up with especially high demand. The day of my visit, the storage area was a forest of CS2.3s, and a secondary area had CS6 pallets stacked high.

To find out more about Thiel Audio,
visit their website at www.thielaudio.com