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Re: Speakers conection ; series or parallel?
8/14/2001 3:50 PM
Rick Payman (10055) wrote:
Actually, for a given amplifier output voltage, in theory you should get 4 times the power output using a parallel connection than you would with a series one.
Basic electric formulas :-
V = Amplifier Output Voltage
I = Output Current
R = Speaker resistance (actually impedance)
P = Power
V = I * R
P = V * I = (V * V) / R
For a parallel connection, the power in each speaker is ( V * V ) / R, giving a total power output of ( 2 * V * V )/ R
For a series connection, only half of the amplifier voltage appears across each speaker, giving a total power of
( 2 * (V /2) * (V/2) ) / R, or ( V * V )/ (2 * R) i.e. 1/4 of that in the parallel case.
A simpler way of looking at it is that the load impedance is four times lower in the parallel case than in the series case; that's four times the current for a given output voltage.
This all assumes a perfect amplifier (zero output impedance) - a real amplifier would give less than a 4 to 1 power ratio output.
Also note that you can never get more output than the total power rating of the amplifier.
I think - Rick.