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Feb15-12, 12:30 PM
P: 78
Quote Quote by Antiphon View Post
That's basically correct. There's a time component to the argument that works without a room where you replace the speaker with a simple resistor.

If you have a 400.0 Hz sine wave and add a second 400.0 Hz sine wave you will get 4x the power. But if you change the frequency of one of the signals to 400.00000000000000000000000000000000001 Hz you will get 2x the power. At first and for many years you will get 4x the power. Then after many millions of years you will get zero. The time average over forever will give you 2x the power.
But this is (mostly ... in time terms larger than one or a few wave cycles) a spatial component where the signals to be added are kept separate until they reach their respective separate amplified speakers?

OK, so I need to just simply add the voltage numbers. How much head-room do I need? In the worst case I would need the coherent case. To do less I would need to understand the nature of my particular signals. In the case of a VoIP teleconference system (say maybe as many as 64 participants at one time), in addition to coherence being very unlikely, it might be rare for everyone to talk all at once.