LA County Code Title 12.08 measures low-frequency bass from sound systems on the C-weighted scale, capping levels at 60 dB(C) inside neighboring residences in unincorporated areas. LASD investigates throbbing-bass complaints from clubs, parties, and modified vehicles.
Low-frequency bass passes through walls and windows even when overall A-weighted decibel readings stay legal. LA County addresses this by allowing C-weighted measurements (dB(C)) under Title 12.08.350 for chronic complaints from amplified bass. Inspectors from County Code Enforcement or LASD acoustic-trained deputies measure inside the affected residence; readings above 60 dB(C) at night (10pm-7am) or 65 dB(C) daytime substantiate a violation. Common sources include nightclubs, backyard parties with subwoofers, modified-vehicle stereos, and home theaters near party walls. The county's commercial nightlife establishments must maintain bass attenuation as conditions of conditional-use permits, often with sound walls or bass traps required.
First-offense bass-noise violations are infractions with fines up to $250 under §12.08.530. Subsequent violations within twelve months become misdemeanors with fines up to $1,000 plus possible CUP revocation for commercial venues. Modified-vehicle bass also draws CVC §27007 citations.
See how El Monte's low-frequency bass limits rules stack up against other locations.
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