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.
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Experiencing Worship, The Study