The DL15ST low/mid-frequency reproducer is a 15-inch, 8-ohm driver designed for professional high-level, high-fidelity monitoring and sound reinforcement. At the heart of this speaker is a carefully engineered drive system. Its design assures linear, low-distortion output, high power capability, and efficient heat transfer.

Incorporated into the design are three exclusive Electro-Voice® innovations. PROTEF™ coating (U.S. patent #4,547,632), a Teflon®-based coating, is applied to the inside diameter of the top plate. Occasional violent power peaks of several seconds may expand a transducer’s voice coil into contact with the top plate, causing failure. PROTEF™ provides protection against such failure. The coating lubricates any rubbing contact and provides electrical insulation between the coil and the steel top plate. The Thermo Inductive Ring (TIR™) and Flux Demodulation Device (FDD™), also included in the DL15ST design, are aluminum castings fastened to the pole of the magnet. They provide a shorted turn to control inductance and provide a major heat transfer path from the voice coil, which improves power handling and reduces thermal dynamic-range compression.
The voice coil itself is constructed of edge-wound rectangular aluminum wire, mounted on a rugged, laminated polyimide former. The complete assembly is low in mass and is fabricated using the most advanced epoxies, insulations, and materials available.
Great care was taken in the selection of diaphragm materials and construction to ensure smooth, musical upper-bass reproduction and accurate low-frequency shock capability (punch). The cone has a moisture-repellent treatment, allowing it to be used in harsh and humid conditions. (Do not expose the cone to direct water or sunlight.)
The DL15ST is a true high-fidelity woofer in every sense, being capable of high output, low distortion, and solid bass response.