Among the speakers: AOL founder Steve Case, Draper Fisher Jurvetson venture investor Tim Draper and Square and Twitter founder Jack Dorsey.

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Thanks in part to ideas born at dB Drag events, the acoustic power of car stereo speakers has increased tenfold in the last ten years, from a maximum of 500 watts per square meter to 5, 000. (A loudspeaker at a rock concert puts out 2, 500 to 3, 000 watts.) Pioneer learned from dB Dragsters to cover speaker coils with ceramics to dissipate heat.

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During a huge demonstration in Tahrir Square commemorating the revolution's first anniversary last month, hecklers continually surrounded a marquee featuring Brotherhood speakers.

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