Tech Tip #16

A horn's functional low frequency can be determined by simply calculating the perimeter of the bell's front and dividing the result into the speed of sound. For example, the JWD DH-30T has a bell diameter of 10 inches. Thus, the perimeter of the bell is 31 inches (pie x diameter). The approximate speed of sound is 13,500 inches per second (using 1125 feet per second). Dividing 13, 500 by 31 equals 435 Hz. Although the frequency response of the horn is lower, reducing the bass control to this level will assure the best performance for paging and avoid damage to the speaker and/or the amplifier.