page_title: Smiley face curve
section_title: Live sound reinforcement
hierarchical_section_title: Smiley face curve / Usage / Live sound reinforcement
caption_attribution_description: English: Stereo graphic equalizer, 15 bands per channel. Português: Equalizador gráfico estéreo, 15 bandas por canal.
context_page_description: A smiley face curve in audio signal processing, is a target frequency response curve characterized by boosted low and high frequencies coupled with reduced midrange frequency power. This curve is often attained by users employing a graphic equalizer, which shows a graphic representation of a "smile" using its frequency band faders to form a curve that sweeps upwards at each end of the frequency spectrum.
  Smiley face curves have been popular with some car audio enthusiasts, disc jockeys, electric bass players, home stereo owners and sound reinforcement operators. Though the graphic equalizer was intended to tailor a system's response to compensate for venue and performance conditions, the smiley face curve is sometimes applied as a purely stylistic effect.
context_section_description: Some concert sound mixers employ the smiley face curve as a tool to help them gain initial control of a sound system. Even with recorded sound, the smiley face curve has its backers. Will Shapland of Floating Earth location recorders said in 2004 that his basic mixing technique for the recordings of the Isle of Wight Festival was to use "a bit of a 'smiley-face' EQ curve on the output" until he got a handle on a new band's mix, at which point he said "your balance comes together and you don't really need it."
  Kip Bradford of Expert Village emphasizes that the live sound engineer must not employ smiley face curves when setting up a sound reinforcement system. Bradford advises that the graphic equalizer should instead be used to "tune the system to the room", taking account of the combined frequency response of the room and the sound system to ensure that all audible frequencies have equal presence.
caption: A stereo 15-band equalizer showing modest smiley face curves
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