Norwalk, CA Noise from Specific Sources: Low-Frequency Bass Limits (2026)
Key Facts
- Octave bands measured
- 63 to 8,000 cycles/sec
- Mic placement
- Property line, 3 ft from wall min
- Mic height
- At least 3 ft above ground
- Readings required
- 3 minimum, 2 min apart, averaged
- Default penalty
- Up to $1,000 fine / 6 months jail
Summary
Norwalk measures every noise complaint, bass included, against the octave-band protocol in Municipal Code Section 9.04.130: readings must span eight bands from 63 cycles per second up to 8,000, taken with a calibrated meter at the property line, so low-end thump from stereos and subwoofers is captured the same way as any other tone.
A. Any decibel measurement made pursuant to provisions of article shall be based on a reference sound pressure of 0.0002 microbars as measured in any octave band with center frequency, in cycles per second, as follows: 63, 125, 250, 500,1000, 2000, 4000 and 8000 or as measured with a sound-level meter using the A weighting network, and using the slow meter response. B. Measurements shall be taken with the microphone located at any point on the property line, but no closer than three feet from any wall and not less than three feet above the ground. C. A minimum of three readings shall be taken at two minute intervals. The sound level shall be the average of these readings.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4609620; v5 updated 2025-12-16).
Full Breakdown
100. 0002 microbars measured across eight octave bands with center frequencies of 63, 125, 250, 500, 1,000, 2,000, 4,000 and 8,000 cycles per second, or alternatively with a sound-level meter using the A-weighting network and slow meter response. The 63-cycle band is the lowest frequency the code specifically calls out, which is the band that captures bass and subwoofer energy. Placement matters: the microphone must sit at any point on the property line, no closer than three feet from a wall and at least three feet above the ground, so the reading reflects what actually reaches the neighboring parcel rather than sound trapped against a structure.
Enforcement officers must take a minimum of three readings at two-minute intervals and use the average, not a single peak, as the measured sound level. There is no separate bass-specific decibel cap; the octave-band data feeds into the article's broader neighborhood noise standard. Norwalk contracts with the Los Angeles County Sheriff's Department for enforcement of Title 9 offenses, including noise complaints.
Violations & Fines
Article III does not label this offense an infraction, so a violation defaults to a misdemeanor under Section 1.16.010: a fine of up to $1,000, up to six months in the City or County Jail, or both, with each day the noise continues counted as a separate offense.
Frequently Asked Questions
Does Norwalk have a specific decibel limit for bass or subwoofer noise?
Where must the sound meter be placed to measure bass noise?
How many readings does an inspector need before citing a violation?
What happens if I'm cited for a low-frequency noise violation in Norwalk?
Sources & Official References
Other rules in Norwalk
California rules heatmap·Compare Norwalk to another location·View the California noise from specific sources overview
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Low-Frequency Bass Limits in Nearby Cities
How other cities in Los Angeles County handle low-frequency bass limits.