Note: This post has been condensed into a dynamic formula that can be found here. Enjoy!
The Easy Speed of Sound Delay Calculator for Marching Band and Drum Corps has been described in a previous article, but we both know that it’s a tricky concept to explain in pure text form. Recently I’ve been working with my friend Pat McNeil to design an online field graph to help visually interpret the equivalent sound delay on a football field. First though, a huge thanks to Pat for his help with coding this, please check out his site at PatMcNeil.net to get in touch or check out his content.
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Speed of Sound Delay Calculation Review:
To quickly review this small portion of the Cost of Timing concept, we start with a musician on any given part of the football field (let’s use a snare drummer for example). This performer plays a single note on the drum and it takes a specific amount of time, at the speed of sound, to reach the listener (in reality this only needs to the the furthest musician forward that the snare drum’s sound needs to reach, so we base it on the front of the field which is where the pit usually stands). What we want to see with this graph is where else on the field it takes the exact same amount of time for that sound to reach the front center of the field. For marching band purposes we use our step size as the distance, 22.5″ per step, so on the field graph below you’ll see both axes using steps as the distance (the field lines are displayed for every 10 yards for reference, but the labels are all steps).
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Entering Data:
When inputting data you’ll need to use the total number of steps behind the front sideline, this means that if you’re behind the back hashmark you’ll still need to find the total number of steps in reference to the front sideline rather than the back hashmark. The same is true side to side by using the 50 yard line, so even if you’re just two steps away from the 20 yard line you’ll still need to use the total number of steps away from the 50 yard line for your input.
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Reading the graph:
When you see the graph you’ll notice the red arc through the position on the field that you input originally. The red arc is showing you where else on the field the sound delay matches yours. If you scroll your mouse over the red arc (or tap your finger on your mobile device) you’ll see the number of steps to any position you choose in the top right (distance back first, then sideways distance second, in steps). Keep in mind the white lines on the football field graph are just the 50, 40, 30, 20, and 10 yard lines, for clarity sake we’ve skipped the 45, 35, 25, 15, and 5 yard lines. For reference on this graph there would be 16 steps between marked white lines. Also note, high school hash marks are dashed while college hash marks are solid lines.
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Get started:
Check out the Cost of Timing Field Graph here and start finding your equivalent sound delay now!
