Phase cancellation (Destructive interference)

A phenomenon that occurs when speakers are 180 degrees out of phase, i.e., what one speaker is trying to produce, the other speaker is fighting to cancel. One speaker's wave is in the positive phase (rarefaction), while the other speaker's wave is in the negative phase (compression).

This definition isn't very accurate either. For "phase cancellation" (destructive interference) to occur between two or more speakers the speakers do not have to be out of phase. For destructive interference to occur, the soundwaves simply need to interact with each other while the soundwaves are not in phase. The speakers may in fact be in phase while this is occurring. This phenomenon is very prevalent in car audio where we sit at different distances from the two speakers or in home theater where the listening positions can vary.

There are other ways for destructive interference to occur. In home audio speaker design the center-to-center distance of drivers in speaker may cause destructive interference. The crossover can also cause two drivers in a given speaker to be out of phase since the crossover will shift the phase of the signal (90* phase shift for every 6db/oct increase in slope), in which case you must wire the drivers out of phase in order for the soundwaves to be in phase at the crossover point.

You can also have destructive interference with a single speaker due to reflections. The reflected sound may reach the listener out of phase with the original sound.

Not nitpicking your definitions.....but also do not want people misunderstanding the information being provided.

Not nitpicking your definitions.....but also do not want people misunderstanding the information being provided.

WOW now that's a definition, I will definetly need to read that one a few time's over. There's no way you are nit picking my answer's Impious, Just corrected them. I know there are ALOT of rumor's about DP, so PLEASE edit as needed. I copied these answer's anyway. I have a strange way of learning(hard headed), but learn quickly when I am corrected.

Yes I am a young bull.