CAD Audio traces its roots to the Astatic Corporation, founded in 1931 by amateur radio operators C.M. Chorpening and F.H. Woodworth, who set out to build a static-free microphone for ham radio. The company incorporated in 1933 and became a pioneer in crystal microphone technology with its D-104 model. In 1988, the pro audio division was spun off as CAD (Conneaut Audio Devices) Professional Microphones, focused on recording and live sound. The two lines were merged under the CAD Audio name in 2008, and the company is headquartered in Berlin, Connecticut.

CAD is best known for its Equitek series of large-diaphragm condenser microphones, which helped define the project studio era of the late 1980s and 1990s. The E100S, a supercardioid condenser with one of the lowest self-noise floors in its class (3.7 dBA), has earned a dedicated following among voiceover artists and vocalists. The E300S, a multi-pattern dual-diaphragm condenser with a gold-vapor-deposited capsule, remains a staple studio vocal microphone. The M179, which uses a variant of the original E300 capsule, offers similar performance in a more affordable package.

Beyond the Equitek line, CAD produces a range of USB microphones for podcasting and content creation, including the budget-friendly U37, as well as the CADLive series for live performance, wireless microphone and in-ear monitor systems, and commercial audio products under the Astatic brand. The company's products span studio recording, live sound, broadcast, and installed sound applications.

CAD has 135 products cataloged on Equipboard, including Condenser Microphones, Dynamic Microphones, and Headphones & In-Ear Monitors. Their gear is featured by 21 artists, with the strongest followings in Rock, Hip Hop, and Pop. Notable users include Lil Wayne, Joe Satriani, and Glenn Fricker. CAD's catalog spans the full price spectrum — from entry-level options to high-end flagships.