It is preferable to diffuse
slap echoes with diffuser panels. Slap echoes may also be absorbed with
carpets, fiberglass panels or drapes. When treating sidewall slap echoes
near the sides of the loudspeakers and/or listeners, it is desirable to
treat both walls evenly, left and right, to provide a balanced sound field.
When treating reflections and echoes, best results are obtained from a
proper mix of direct and diffused sound. That is, a balance of diffusive
and absorptive materials strategically placed in throughout the room. The
key in trying and applying all types of room treatments is to utilize test
equipment which is designed to measure the time, energy and frequency relationship
with the room. Or you can just listen as you go, use the proper treatment
for the identified condition, and experiment, experiment, experiment!
Standing waves are high and
low pressure energy buildups, which are determined by frequency and room
dimension. They are so named because they do not travel or propagate. Instead,
they become anchored at various spots in a room determined by boundary
conditions. Although standing waves occur at all audible frequencies in
a contained space, our focus will be on the widely spaced, low frequency
waves. These low frequency standing waves cause severe peaks and dips in
the system's in-room bass response, creating the dreaded "one-note bass"
while obscuring truly deep bass. All rooms except those very large rooms
or halls (whose wavelengths are so low in frequency that they can be ignored)
have low frequency standing waves of consequence.
You can graphically show
which standing wave frequencies will affect a given room by plotting some
simple calculations on graph paper. First, calculate the frequency of the
lowest fundamental peak (f) for each room dimension (length, width and
height, represented by "d"), by dividing 1130 ("v", or the speed of sound)
by twice the dimension in feet, using the formula f = v/2d. The dimension
("d") is doubled to account for the sound wave's round trip. Plot your
results on separate lines for the room's length, width and height, one
above the other, on your graph paper. Scale the horizontal axis from 20Hz
to 150Hz in 10Hz increments. Now plot the additional peaks caused by the
even multiples of the fundamental frequency up to 150Hz. For example, if
your fundamental standing wave frequency is 50Hz, you will also have buildups
at 100Hz and 150Hz. Beyond 150Hz, the spacing of standing waves becomes
close enough to ignore. On your graph, any points close to each other will
indicate an excessive buildup of energy at that frequency. Ideally, standing
waves should be evenly spaced, which will provide a flatter in-room response
from most locations. A spreadsheet file on a computer could easily be created
to make these calculations and plot your graphs automatically.
Experiencing Worship, The Study
Used by churches all over the world to help teach worship, the Experiencing Worship study can help your worship team too.
Your team will learn why we worship and gain a better understanding of how to worship.
One user said..."Your 5 week study course has made a tremendous impact on my life in the study of worship... I would like to express my thanks for a well written study course that leads into a higher realm of praise and worship."
The Paul Langford Project
This is the debut album by EXW friend Paul Langford. Paul is a Chicago based singer, arranger, keyboardist, producer and conductor. Paul has a career that spans 14 years. Paul's work includes arranging for groups like GLAD, Voices of Liberty, VoiceTrek, The Chicago based "Caroling Party" and Day of Discovery Singers. His arranging has appeared on recordings side by side with greats like Gene Puerling and David Maddux, and he has sung with Don Shelton, Bonnie Herman and Bob Bowker, among others.
Used by churches all over the world to help teach worship, the Experiencing Worship study can help your worship team too.
Your team will learn why we worship and gain a better understanding of how to worship.
One user said..."Your 5 week study course has made a tremendous impact on my life in the study of worship... I would like to express my thanks for a well written study course that leads into a higher realm of praise and worship."
This is the debut album by EXW friend Paul Langford. Paul is a Chicago based singer, arranger, keyboardist, producer and conductor. Paul has a career that spans 14 years. Paul's work includes arranging for groups like GLAD, Voices of Liberty, VoiceTrek, The Chicago based "Caroling Party" and Day of Discovery Singers. His arranging has appeared on recordings side by side with greats like Gene Puerling and David Maddux, and he has sung with Don Shelton, Bonnie Herman and Bob Bowker, among others.