Soundpost Acoustics of Longmont was engaged to monitor sound levels during the August 2016 Vertex Music Festival at the Meadows near Buena Vista.
The report states at no time did sound levels exceed the 105dBA limit at the property line, but acknowledged there was a more accurate measurement of bass tones that were detected far from the property boundary.
The report sent to Chaffee County planning manager Jon Roorda dated Aug. 16, 2016, states sound levels were monitored at several locations along the property boundary concentrated near the main music stages and two off-site locations in a nearby neighborhood north of the Meadows.
In the discussion segment, the report states:
“The 105 dB(A) sound pressure level limit at the property line was not exceeded at any point during the music festival.
“However, we observed that low frequency (bass) sound levels were very high, especially for electronic dance music artists including Gramatik, Odesza and Seven Lions. These performances occurred during late nighttime hours and the bass energy was easily audible along and even well beyond the property line,” the report states.
It noted that the A-weighting system is the industry standard and most commonly used weighting scale.
“The C-weighting scale is more appropriate for accurately measuring bass-rich sound sources and correlates better to human perception at high sound levels. … Since in this case the bass levels were high, C-weighted measurements may have better correlation with neighborhood responses than A-weighted measurements.”
The bass energy was audible at the test site north of the Meadows, the report said, but clarified that “it was difficult to measure above the ambient noise levels. Note that the music playing in the distance is not detected by the A-weighted scales since it consisted mostly of low frequency sound.”
The county commission approved a 2017 permit request in October 2016 from Vertex promoter Madison House Presents, but restricted sound levels to 85 dBs.
Madison House representative Michael Sampliner responded to the commissioners’ decision to lower the decibel level, saying that level would be difficult to adjust to.
“If we had to play at 85 dBs, you’re taking out the concert experience,” Sampliner said. “It’s a level at which you would feel like you were in a living room, as opposed to a concert experience. It’s really untenable in any kind of way to put on a show at an 85 dB limit.”
Vertex released a statement in November announcing the festival was cancelled.