B-52 Professional, the brand of E.T.I. Sound Systems, Inc., is a family-owned pro audio and guitar amplifier manufacturer based in Huntington Park, California. Founded in 1989 by Eli El-Kiss and his son Avi, the company began when the pair built their first speaker cabinet with a table saw and a single sheet of plywood. That initial cabinet attracted over a hundred orders from a local distributor, launching what would become a prolific product line spanning live sound reinforcement, mobile DJ systems, permanent installations, and guitar amplification.

On the pro audio side, B-52 is best known for the Matrix series of active PA systems — self-contained packages that pair powered subwoofers with satellite speakers and built-in mixing. Models range from the compact Matrix 200 to the 1,600-watt Matrix 2500, many featuring integrated BBE Sonic Maximizer processing and Celestion drivers. The ACTPRO series of powered speakers and subwoofers rounds out the live-sound lineup. For guitarists, B-52 produces tube amplifier heads under the Stealth Series banner, most notably the AT-100 — a 100-watt, three-channel, all-tube head with six 12AX7 preamp tubes and four 6L6 power tubes that has earned a reputation as a "sleeper" amp for its combination of versatile tone and modest price. The ST-100A offers a streamlined take on the same platform with selectable solid-state or tube rectification.

B-52 has 10 products cataloged on Equipboard, including Guitar Amplifier Heads, Guitar Amplifier Cabinets, and Combo Guitar Amplifiers. Their gear is featured by 3 artists, with the strongest followings in Rock, Jazz, and Electronic. Notable users include Andrew Whiting, Ronni Le Tekrø, and Illicit Nature.