Digging into Psychoacoustics
“Psychoacoustics” may sound intense, but it’s really just about how people perceive sound. So, in a worship context, psychoacoustics are incredibly important.
What people hear is a result of not just direct sound, but indirect, as well. In other words, the sound that’s reflected off other objects in the room. In fact, most sound arrives at a listener’s ear as reflected sound.
Reflected sound is inherently inaccurate, because:
- It arrives at a different time than original sounds, which can be discordant.
- It will never have exactly the same frequency content as the original sound.
- Both lateral and vertical reflections occur, further complicating matters.
That’s why accounting for how a space affects psychoacoustics – the way people perceive sound – is so important.
“We know that well over 75 or 80% of what we hear is reflected off of walls and floors and ceilings,” Allensworth said. “It’s one reason why a full room sounds different than an empty one. … When a person hears the same thing at different times in different ears, it creates cerebral confusion.”
However, partnering with an experienced solutions provider like Bose can help. For any sound system to be successful, the acoustics of a space have to be under control, and Bose can help make that happen.
In particular, it’s important to consider:
- How to reduce parallel and “hard” surfaces that can lead to poor acoustic performance.
- Implementing curtains and other solutions to help absorb and dampen sound.
- How speaker layout can be used to alleviate acoustic challenges.
- Whether the sound system, itself, is tuned properly and performing at an optimal volume.
Prioritizing Audio Solutions
Not all sounds in a given space are created equally. Live music, recorded video, and speaking all need to be accounted for, and it’s important to find a solution that works best either for all three or, at the very least, which your service incorporates most often.
“You’ve got to really take a full snapshot of what [a church’s] needs are,” Allensworth said. “What’s their primary, what’s their secondary, and what’s out there on the edge? Do they do concerts? … You have to look at the whole picture. That’s why one size doesn’t fit all.”
While Allensworth admits that no church leader needs to know every technical in and out of their sound system, establishing a base level of understanding can go a long way.
Let’s explore some common terms that might come up during your audio planning process, from room design to implementation.
Range (Frequency Response)
This simply refers to the range a given system can achieve in terms of the sounds it can produce. The human ear hears in the range of 20 Hz to 20 kHz, but particular instruments could call for a system that can perform outside that range, such as deep bass guitars or pipe organs. You need to identify your own church’s needs and find a range that matches. Playing lower and louder translates to higher costs, and you may not even need a range that extensive.
Sound Pressure Level in Decibels (dB SPL)
Often, the solution to poor acoustic performance is “louder,” but that’s not optimal. dB SPL essentially refers to the intensity and “loudness” of sound. Optimally, Allensworth said, he likes systems to be able to run at 75% “power” and peak around 110 dBA – about the loudness of a typical dance club with music on.
Types of Loudspeaker Arrangements
o Line Array
Line arrays are typically individual boxes arranged in a column that, when spaced closely together, form a cohesive wavefront, acting like one speaker. This arrangement is good for achieving long distances with little dropoff.
o Point Source Boxes
They focus sound in one direction but are subject to the 6 dB drop off. However, they’re very affective in targeting specific areas and are versatile.
o Constant Curvature Arrays
Unlike in a line array, the vertical coverage patterns in the mid-high frequencies are separated, with each individual loudspeaker throwing its own distinct “wedge” of sound out to the audience. These can simplify array configuration.
o Column Arrays
These are single enclosures with multiple loudspeakers arranged in a line array format. These excel in highly reverberant spaces and are great for speech.
Loudspeakers can be arranged in three different ways: Left-Right, Center, or Left-Right-Center. Left-Right arrangement is excellent for a music focus. Center arrangements can benefit a focus on speech. And Left-Right-Center arrangements enhance both music and speech but increase complexity.
One tool that can help a system designer or acoustic consultant find the right setup for your needs is Bose Modeler software.
Bose offers a variety of solutions aimed at producing the perfect worship audio and helping you decide exactly how to meet your church’s unique needs.
Bose can assist you in selecting the right loudspeaker solution and arrangement for your unique needs.
To learn more about how innovation can help support inspiration and allow you to produce shared worship experiences that capture the heart, visit our places of worship page.