After you've plotted the
graph, play tones to verify your standing wave calculations. Use a sweep
tone generator or a test CD recording of a sweep tone, along with your
SPL meter or real time analyzer. As you tone sweep from 20Hz to 150Hz,
you will notice that the volume from your listening position increases
and decreases at different frequencies. Pause the sweep tone at a frequency
where the volume is at it's loudest from your listening position, then
slowly walk around the room. Notice how the volume of the tone changes
dramatically as you move around, louder in some areas, barely audible in
others. These high and low pressure zones in different positions around
the room are standing wave fundamentals and their multiples. These "room
modes" are dependent on the room's dimensions in relation to the frequency
of the fundamental and its multiples. Note the standing wave energy distribution.
The sweep tone test is a
great way to prove your predictions and observe very real proof of the
standing wave phenomenon. Remember to use caution when playing test tones
through speakers, as you can easily drivers during this test. If you're
using a tone generator, use only sine waves for testing, not square waves.
Due to the length of low
frequency standing waves, they cannot be minimized by applying foam, insulation
or carpet to the walls. Typically, fixed bass traps are not practical either,
being massive and complicated to build, and portable traps are only minimally
effective unless used in large numbers. Now that we know how room dimensions
and the fundamental frequencies and their multiples interact, we can position
the speakers and listeners to minimize the effects of standing waves. Using
our graphs, we can determine the most desirable speaker, subwoofer and/or
listener locations, based on the locations of the energy buildups (standing
waves) from the fundamentals and their multiples corresponding to each
room dimension.
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.