Rockford Fosgate began with Jim Fosgate's dream of high performance car audio. When the first Fosgate PR-7000 automotive amplifier was shown at the Chicago C.E.S. in 1973, there weren't any head units on the market with line level outputs and there weren't any dealers willing to order a $300 car amp. This didn't stop Jim from pursuing his goals. He had found a better way and he was determined to educate the market. Jim Fosgate's passion for audio was nurtured by a friend and avid hobbyist, a dealer who lived in the mid-west.

While Fosgate's company Pro-Line in Salt Lake City was building radio transmitters and receivers for remote control airplanes, Jim Fosgate was developing a circuit called a "Frequency Energizer." The "Frequency Energizer" circuit was developed for Fred Hulan's Audio Mart in Kansas City. Fred was doing professional installations in homes and theaters using a then state-of-the-art piece of test equipment called an "Acoust-A-Voice." It incorporated pink noise, a 1/3 octave equalizer and an oscilloscope. Fred kept notes on the inefficiencies he saw repeatedly in each installation. He shared those findings with Jim Fosgate whose Frequency Energizer circuit would compensate for loss in the high and low end frequencies. (Starting to sound familiar?) This first unit was designed to run through a tape loop in the receiver or preamplifier. The birth of Fosgate car audio came when the Frequency Energizer was incorporated into a 30 watt car amp by Jim and some of his after hours enthusiasts. These late night experiments lead to that first Fosgate amp, the PR-7000.