As every festival organiser will know, the complaints that arrive during a headline set rarely come from inside the arena. They come from a housing estate half a kilometre away, at a moment when your front-of-house readings are comfortably inside your licence limits and nothing on the stage-side meter explains what those residents are reacting to. Almost always, the answer is the bass.<\/em><\/p>\n\n\n\n We set out the fundamentals of getting event noise right earlier this year in our Guide to Noise Management for Event Organisers<\/a>. This piece looks at the single technical issue behind most off-site friction \u2013 low-frequency sound \u2013 and why the place and the metric you monitor with matter just as much as the limit itself.<\/p>\n\n\n\n Most event noise limits are set in A-weighted decibels, dB(A). A-weighting is a filter that approximates the sensitivity of human hearing, which responds far less to very low frequencies than to the mid-range. That makes dB(A) a sound, standardised basis for licence conditions \u2013 but as a by-product it deliberately discounts low-frequency energy. A stage can therefore sit comfortably within a dB(A) limit while still pushing a great deal of sub-bass into the surrounding area, because the metric you are judged on barely counts it.<\/p>\n\n\n\n That matters because low frequencies behave differently from the rest of your mix. Long wavelengths lose less energy over distance, bend around obstacles rather than being blocked by them, and couple into the structure of buildings \u2014 so residents often hear and feel bass indoors, windows shut, long after the higher-frequency detail has faded to nothing. The result is a genuine gap between measured compliance and lived experience, and it sits almost entirely in the low end. It is well documented in event acoustics; the Institute of Acoustics has published specifically on low-frequency sound at outdoor concerts because it is such a persistent source of complaint.<\/p>\n\n\n\n The practical implication is to make sure your monitoring captures low-frequency content, not only overall loudness. In event acoustics this is often done by tracking the relationship between C-weighted and A-weighted levels \u2013 C-weighting discounts far less bass, so a wide gap between the two is a reliable signal that significant low-frequency energy is present. It is worth agreeing early with your acoustic consultant and monitoring provider what you will measure and against what triggers, so your sound engineer has a number that moves when the bass does and can act before the phone rings.<\/p>\n\n\n\n Even the right metric tells you little if it is measured in the wrong place. Stage-side readings describe what the crowd is getting; they say almost nothing about what a resident half a mile away receives. Continuous monitoring at the site boundary and the nearest noise-sensitive locations is the foundation of a defensible strategy, because it measures the sound as it actually arrives \u2014 accounting for distance, wind, and the shielding of the ground and buildings in between. Our Sitesens Boundary Monitor and EM2030 sound level monitors are built to sit out at those locations for the length of an event and report continuously in demanding outdoor conditions.<\/p>\n\n\n\n The value compounds when that data is shared. Through Sonitus Cloud, the same live measurements can be visible to your production team, your acoustic consultant and the local authority at once, with automated alerts by SMS or email as levels approach your agreed thresholds. Your engineer can trim the low end the moment a trigger is nearing rather than after a complaint is logged; the authority sees the same numbers you do in real time; and when a resident does get in touch, you can respond with measured evidence rather than reassurance. Festivals that monitor openly and are seen to act on what they find tend to find community goodwill follows \u2014 and that goodwill is what protects your licence, your dates and your welcome next year.<\/p>\n\n\n\n The bass will always travel furthest. The question is whether you are measuring it, and whether the people it reaches trust you to be listening too.<\/p>\n\n\n\n Sonitus Systems offers both the hardware and software for a range of environmental parameters on a continual basis, with real-time information available through our Sonitus Cloud dashboard. For more details on our indoor and outdoor noise and air quality monitoring products and services, please contact the team at https:\/\/www.sonitussystems.com\/contact-us<\/a><\/strong><\/em><\/p>\n\n\n\n <\/p>\n","protected":false},"excerpt":{"rendered":" The Bass Travels Furthest: Monitoring Low-Frequency Noise to Keep Your Festival and Its Neighbours on Good Terms As every festival organiser will know, the complaints that arrive during a headline set rarely come from inside the arena. They come from a housing estate half a kilometre away, at a moment when your front-of-house readings are …<\/p>\nWhy “within limits” and “keeping the neighbours happy” can diverge<\/h4>\n\n\n\n
Monitor at the boundary, and share what you measure<\/h4>\n\n\n\n
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