Wayne Parham Messages: 18787 Registered: January 2001
Illuminati (33rd Degree)
Even at very low frequencies where the line becomes a point source, there is still response averaging from reflected path length differences. The end drivers in a 5 foot line are 1/2λ apart at 112Hz and 1/4λ apart at 56Hz. So those two will cancel at 112Hz but others in the line will fill in the response at that frequency. The same kind of thing happens to reflected modes coming from the floor and ceiling, although the distances will be greater since the floor and ceiling are spaced away from the line. This makes the frequencies lower where the averaging modes occur. A 5 foot line acts like a point source below 56Hz since every driver is 5 feet apart or less. But reflections may be greater than this distance. Still, the number of drivers tends to average the field, in the same way the 112Hz mode from the two most distant drivers are averaged by the drivers in between.