FRONT OF HOUSE
[ 5 “NEED TO KNOWS” ABOUT ROOM ACOUSTICS | Kent Morris ]
Acoustics are what happens when sound without interruption and is highly intelligible, back a bit of low-mids in the front fills, add
encounters boundaries. Sound propagates as assuming a proper mix engineer is at the helm. some 5KHz to the over-balcony fills and pull
waves through the air in a defined pattern until When the listener perceives more material back the subs some to get a reasonable mix
contacting a surface. Whether it is a human through reflected means, the retention and in every section.
being, a wall, or a pew, acoustics are easiest intelligibility drop dramatically. Thus, we want to to understand via what they encounter in their maximize the linearity between output device 5. Know why things sound the way they do
pathway. Hard, reflective surfaces will bounce (loudspeaker) and human ear. in your room. If the sanctuary contains an
nearly the entirety of sound waves back the
orchestra pit, it will resonate around 125Hz. Be
same direction they arrived (angle of incidence 2. You cannot overpower the room. I have ready to pull that frequency out of the orchestra
is same as angle of reflection) while soft, witnessed even seasoned engineers attempt matrix. Under-balcony areas tend to enhance
absorptive boundaries, such as humans, only to overcome poor acoustics by increasing the energy around 350Hz, so making a gap in the
reflect some frequencies while trapping others. level of the system output, to no avail. The response in that region makes sense. Acoustic
Sound travels at roughly 1,130 feet per second, room always wins. Instead, work with the room. guitars often ring at 630Hz, so make a cut
depending on air density and altitude, which If it will not allow energy below 80Hz, then hi- there when dialing in that channel. Understand
is rather slow compared to light. So, multiple pass everything at 85Hz and build the mix to the ceiling grid vibrates at 55Hz, so explain
paths from source to destination mean arrival that reality. to the bass player why you are notching that
times will vary and will interact in myriad ways,
frequency.
making discernment of speech difficult. Having 3. In reflective environments, don’t muddy a basic understanding of acoustics can make the mix with effects. If the RT60 (time it takes Acoustics can be a nightmare when parallel
mixing more productive and enjoyable. Here in seconds for sound to decay 60dB) is four walls create standing waves, but they can
are some things to know: seconds, there should be no effects used at all also enhance worship when they are properly
in the mix. There simply is no point. suited for the task at hand. While not much can
1. Room acoustics are a complex combination
be done to reposition boundaries, temporary
of origin, destination, and boundaries. For 4. Acoustics are different all over the room. gobos can be set up to divide acoustic areas
speech, the goal is to provide as much direct Just because it sounds great in the tech booth on-stage and absorptive materials can be hung
energy to the listener as possible, with as doesn’t mean it sounds good in the seats. Take on walls to remove the worst of reflections. The
little reflected energy as possible. When the the time during soundcheck to walk the room key to success is to be aware of what the room
pastor is speaking, their voice is either in the and listen to how it sounds down front, up in is doing to sound and how best to work with it
direct or indirect field, depending on where we the balcony, over by the rear wall, etc. Then, to achieve a reasonable mix.
measure. Direct field energy comes from the make adjustments as the LMS (Loudspeaker primary source (loudspeaker) to the listener Management System) allows. Perhaps dial Kent Morris
35 year veteran of the worship technology arena
with a passion for excellence balanced by the
knowledge digital is a temporary state.
photo courtesy CCISolutions.com
60
May 2018
WorshipMusician.com