Jacksonville, NC Noise from Specific Sources: Low-Frequency Bass Limits (2026)

Sec. 15-27 defines 'plainly audible' as any sound a person can detect with unaided hearing, and specifically states that for a portable or personal vehicular sound system, the detection of the rhythmic bass component of the music is sufficient to verify plainly audible sound. The officer doesn't need to identify the song title, lyrics or artist, only the audible bass. Sec. 15-56 then sets the numeric standard for cars, trucks and other vehicles: amplification equipment can't be operated so it's plainly audible 25 feet in any direction from the vehicle, or so it registers more than 70 dB(A) measured 10 feet or more away.

This overlaps with the right-of-way rule in Sec. 15-55(a)(4), which separately caps vehicle-adjacent speakers in public streets at 70 dB (day) or 60 dB (night) within 10 feet, or plainly audible at 25 feet, unless the operator has a police department permit. Because 'plainly audible' turns on the bass line rather than a full decibel reading, a Jacksonville Police Department officer can write a citation from the sidewalk without deploying a sound meter, relying only on the rhythmic thump test written into the definition.