For most of us who've had the experience of getting a custom set of IEMs made, there are two steps to the process. First is getting an impression of your ears made, then there's the delivery of the finished product a short time later. A tour of Ultimate Ears' headquarters and manufacturing facility reveals the unseen parts of the process. And now a portion of that process includes a digital detour on the path—an alternative methodology as you'll see below (and as described in more detail in Pro Sound News, September, 2014, page 5).
Below: The process begins with making a molded impression of the user's ear. A small ball of cotton on a string is inserted in the ear to protect the eardrum (the string also serving later to help remove the cured impression). A pliable, fast-setting silicone gel is squirted into the ear canal.
Below: The resulting impressions are rigid enough to be used to make a mold in which final IEM shells can be formed. At UE, the impressions (these below just happen to be green) go in a sleeve with the work order and in one of two directions. In the traditional “analog” path, the impressions go to a production lab for manual manipulation and IEM shell casting.
Below: The original impression is shaped and excess material removed by one of a handful of trained and experienced technicians.
Below: A more rigid clear plastic is poured around the impression to produce the mold in which final IEM shells can be cast. To the right are cups in which molds are formed with the device that delivers the thick liquid which, when cured, becomes the mold.
Below: A wide variety of colors are available for the final cast IEM shells, though Ultimate Ears is encouraging clear in-ears for one simple reason: it's easier for users to see when the IEMs are clean, or when ear wax has built up, which eventually will affect performance.
Below: In the new digital path, the impressions are inserted into a three-dimensional scanner. The resulting digital file is fed into a 3D CAD program, as with the left/right pair below.
Below: The same technicians experienced in physical optimization of ear impressions at UE were trained on CAD operation, carrying years of experience across to the new process. Seen here, areas of the impression can be trimmed or can have millimeters of thickness added. Best of all, every step can be undone if the fit needs to be revisited.
Below: The image below represents a final file, ready for 3D printing. You can see that the exit ports have been placed as well. Visit our Pro Sound News September, 2014 issue's "There's More" page for video of the digital impression manipulation (scroll to Page 52).
Below: This 3D printer has been optimized by UE to produce IEM shells that are indistinguishable from traditionally molded clear shells.
Below: Even through a reflection on the outside of the printer, the laser trace can be seen as it follows the pattern of a thin layer of the IEM shell being printed.
Below: Resulting 3D-printed shells
Below: For each IEM pair, whether created through traditional or digital processes, drivers and crossover components are mated and semi-rigid plastic tubes attached, to be slid into IEM shells after test and optimization.
Below: The last production steps are the fitting of leads and placement of the cap on the IEM shell. This is where visual customization is possible. A wide variety of cap cover colors are available; band logos and other text or graphics can be used—even alternate materials can be used, as with this very limited availability leather-capped set of UE Reference Monitors.
The final step in the process is delivery to the customer. As befits a premium, custom product, the 'unboxing' experience itself is impressive—then there's putting them on for the first time, feeling the 'made for you' fit and pressing 'Play.'