Low-Frequency Bass Limits: Chicago vs Oak Park
How do low-frequency bass limits rules compare between Chicago, IL and Oak Park, IL?
Chicago and Oak Park have similar restriction levels.
Chicago, IL
Cook County
Chicago measures low-frequency bass at 55 dBC inside neighboring residences after MCC 11-4-1115 was updated to capture sub-bass that travels through walls. C-weighted readings allow inspectors to cite venues whose sound passes A-weighted limits.
View full Chicago rules →Oak Park, IL
Cook County
Cook County Chapter 38 environmental control rules and Illinois Pollution Control Board Part 901 set octave-band sound limits that capture low-frequency bass through 31 Hz and 63 Hz bands. dB(C) measurements supplement dB(A) when complaints describe rumble or thumping bass.
View full Oak Park rules →Key Facts Comparison
| Fact | Chicago | Oak Park |
|---|---|---|
| Code | MCC 11-4-1115 | - |
| Interior limit | 55 dBC inside neighbor | - |
| Exterior limit | 55 dBA property line | - |
| First fine | $600 | - |
| Max fine | $10,000 repeat | - |
| State framework | - | IPCB Part 901 octave bands |
| Low-freq bands | - | 31.5, 63, 125 Hz |
| Measurement | - | dB(C) plus octave bands |
| Indicator | - | dB(C)–dB(A) > 10 dB |
| Enforcer | - | Cook DEC and IEPA |
Highlighted rows indicate differences between cities.
Chicago FAQ
What is dBC and why does Chicago measure it?
C-weighting captures low-frequency bass that A-weighting filters out. Chicago added the dBC limit because nightclub bass often passes A-weighted tests yet still rattles neighbors' walls and windows.
Can a bar lose its liquor license for bass complaints?
Yes. Repeated MCC 11-4-1115 citations create grounds for license review under MCC 4-60-140 nuisance and disorderly premises rules, especially after Police Department complaint logs.
Oak Park FAQ
Why does my neighbor's bass shake the windows but barely register on a dB meter?
Most consumer apps measure A-weighting, which deemphasizes low frequencies. Use C-weighting or a 31.5 Hz octave band measurement, which is what Cook County and IEPA inspectors rely on for bass complaints under IPCB Part 901.
Do Cook County rules apply to residential subwoofers?
Yes. IPCB Part 901 octave-band limits apply at any residential receiving land property line regardless of source. A subwoofer audible across the property line during nighttime hours likely violates 31.5 Hz and 63 Hz nighttime limits.
What's the difference between dB(A) and dB(C)?
dB(A) approximates human hearing sensitivity and undercounts bass; dB(C) is nearly flat and captures low-frequency energy. Inspectors compare both readings to confirm low-frequency dominance before issuing a Cook County Chapter 38 citation.
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