Excessive Sound Pressure Level of a particular Frequency, that is Dependant upon the Dimensions of a Resonant room. Sound Wave upon Sound Wave building up together to exaggerate a particular Frequency.
Undesired effects that occur when two or more waves of the same frequency are present at the same time. This may happen, for example, when the transmitter, transmission line or antenna are not properly matched to each other.
Associated with room resonances, at low frequencies, these can result in large variations in sound level at different frequencies at different locations in the room. The bass sounds different as one moves around a room. See Resonance.
These are irregularities (quite audible and unwanted in the bass range) that result when sounds reflected back and forth between the walls of a room interact with each other and with the direct sounds from the speaker systems that produced them to form alternate reinforcements (peaks) and nulls. The effect is dependent upon the size and shape of the room and the listening position and, to a smaller degree, on the positioning of the speakers. Standing waves can be detrimental to sound reproduction at lower frequencies in small and/or badly proportioned rooms, where their effects are often extreme.
When a transmission line is terminated in its characteristic impedance, current and voltage are in phase at any point on the line and the maximum energy from the transmission line is dissipated by the termination. If the termination is of some other impedance, part of the wave propagating along the line will be reflected back toward the source. This will act with the forward travelling wave to produce peaks and nulls and not all the transmitted energy is absorbed by the load termination. A transmission line in this condition is said to have standing waves upon it.