Quarter Wavelength Calculator
Acoustitape
Welcome to the AcoustiTape Rev 4.
The AcoustiTape is 3 meters long, so it covers frequencies going down to 115Hz.
It also shows the time periodicity for each frequency as well as how far sound travels over a given period.
Frequencies printed in bold are the ¼ wavelength of the frequency printed next to it. The purpose of the bolded frequency is to associate the predicted dip in the frequency of a loudspeaker when placed a certain distance from the wall behind it. Bass waves are omnidirectional and while the longer wavelengths travel directly to the listener, they also travel ¼ wavelength to the wall behind it, bounce off it and return to the loudspeaker tenths of milliseconds later only to be 180 degrees out of phase with the direct sound. (¼ +¼ = ½ or 180 degrees out of phase)
Printed on the reverse side is a standard measuring tape in inches and centimeters.