The Darling’s Waterfront Pavilion kicked off its summer concert series Saturday with the return of Rise Above Fest, a daylong concert featuring a lineup of well-known metal bands. While many in the past have turned out to hear their favorite metal tunes, many Bangor residents have complained about the noise from the show, more so than most other concerts.
The city has grappled with noise complaints since the launch of the Waterfront Concerts series in 2010. Last year, Bangor hired the Massachusetts-based audio consultant firm Acentech to find a balance: an acceptable noise level for Bangor residents’ quality of life that also would allow Darling’s Waterfront Pavilion to remain an attractive venue for performing musicians.
But reaching that balance can be tricky, said Benjamin Markham, director of architectural acoustics at Acentech and author of the 2014 report recommending how Bangor can reduce noise complaints.
The noise produced by a rock concert on average measures between 108 and 114 decibels — about as loud as the inside of a steel mill and louder than a jackhammer. By comparison, a normal conversation is about 60 decibels, an interstate highway measures 76 decibels and a baby’s cry comes in at 115 decibels. A noise begins to cause pain to the ear between 115 and 140 decibels, and prolonged exposure to noise in excess of 85 decibels can cause hearing loss.
When it comes to managing noise, Markham said it’s a matter of looking at a noise’s source, its path and its receiver, then assessing the options that can be deployed along the way.
The source: That, of course, is the performer, but also the sound system that projects his or her sound. And at Darling’s Waterfront Pavilion, the sound systems travel with the acts, presenting a sound management problem, Markham said. Not all of these systems are created equal: Some offer more control than others over the direction of sound, he said.
The path: Markham said that the path between the source and receiver is the chief problem for Bangor’s outdoor concert venue. The Acentech report examined options that would modify the path of concert noise in order to reduce the complaints. If a noise can’t be quieted at the source, path modification is commonly the next step.
The two options considered in the Acentech report were a roof that would be constructed over the audience and a wall around the venue that would have blocked sound from entering residential neighborhoods.
Both options were ultimately discarded as cost-prohibitive measures that would have obstructed views of the waterfront during the offseason.
The wall, for instance, would have to be two stories high in order to block just high- and mid-frequency noise from the highest speakers. But few of the complaints cited in the report were about these sounds.
Both options would only have been marginally effective at managing low-frequency sounds — think a bass in metal music — which the report cites as the source of most complaints. Low-frequency sounds have long wavelengths that enable them to travel farther and to more easily navigate around and over boundaries. Long wavelengths are able to bend, or diffract, around barriers.
“It is easier for a wall to block high-frequency than low-frequency [sounds],” Markham said.
To steer the path of concert noise away from many area residents, the Darling’s Waterfront Pavilion was redesigned in 2013 to face downtown, not Bangor’s residential west side.
Receiver: The receiver includes both the audience and the surrounding communities of Bangor and Brewer.
“One important aspect of human response to sound is that we react to certain sounds differently,” Markham said.
Understanding “how loud [the concert] is in relation to the background sound” is key to finding where to draw that line between what’s too loud for residents and what’s not loud enough for performers.
This means finding out how much louder it gets in an area when a new sound such as Rise Above Fest is introduced.
Last year, three shows were markedly louder than the prevailing ambience of Bangor’s west side: the Rise Above Fest, Brad Paisley and Tim McGraw.
Rise Above Fest, for instance, on May 10, 2014, had low-frequency sounds measured consistently between 90 and 110 decibels, while low-frequency sounds at Celtic Women on May 30, 2014, rarely rose above 90 decibels.
“If you’re in a location that’s already pretty noisy, you aren’t going to notice the music,” Markham said. “If you’re in a residential neighborhood that’s quiet, you’re going to hear the music.”
Because the mixing station is fixed at the Darling’s Waterfront Pavilion, Markham said it provides an effective means of enforcing sound level limits, such as the number of times low-frequency sounds exceed 110 decibels, as this has been the source of many complaints.
“The thing [Bangor] has the most control over is the volume knob,” Markham said.
But while Markham said this is the most effective and least costly option, it may not reduce noise enough to make everyone happy.