Jeffreybehr, please explain what's reversed. I'll fix it if it's wrong.
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Here is what is wrong, Nsgarch. Electrostatics do not demand high current, but are voltage driven. In fact, all speakers respond to the voltage applied at the terminals, depending on their sensitivities. that is why sensitivity is stated as sound output (db)/2.83V into 8 ohms (which is 1 watt). Thus, if a speaker outputs 90db at 2.83V input and it is an 8 ohms speaker (at that frequency) and we expect 90db at the same 2.83V input, but at a different frequency which is at 4 ohms, then the power requirement will be double, therefore the amps double. Electroststics are essentially voltage driven devices, i.e. the membrane responds to the varying voltage of the stator panels. generally 'statics' don't demand a lot of current. Dynamic speakers also respond to voltage, but due to their drive systems, they also need power, thus the need for more current at lower impedences, therefore more amps. Note, if the amplifier is incapable of supplying the necessary current for the power demand, it is the voltage that sags, thus the output from the speaker 'sags'. Tube amps are generally not great current producing devices beyond their power limits into specified loads, but their stability with voltage makes them a good marriage with electrostatics. High current capability SS amps do much better with varying impedence dynamic speakers than tubes, usually. That is the part that you had reversed, I think. Respectfully, Bob P. |
Inpep, you state: Electrostatics do not demand high current, but are voltage driven.Is that your opinion, or do you have a reference for that 'fact'? Electroststics are essentially voltage driven devices, i.e. the membrane responds to the varying voltage of the stator panels.Except for the Quad 57, all other commercially manufactured electrostats have a constant, DC, high-voltage/low-amperage potential in the stators (supplied using AC from the wall) and a varying potential in the moving membrane which is derived from the audio signal. They are NOT voltage *driven* since there is no work for the voltage to do, ie, no electrons for it to MOVE between two points. Only electroSTATIC forces are created. An electroSTATIC speaker is simply a big, flat, capacitor. As I'm sure you know, a given value capacitor passes more and more signal (alternating CURRENT) as the frequency increases -- which is why the impedance (resistance) of stats GOES DOWN AS THE SIGNAL FREQUENCY GOES UP ;-) For a freally clear expanation of circuits and how they work, I highly recommend this site: http://www.allaboutcircuits.com/vol_1/index.html . |
Adman227, your quote (from Montytx) is why I said I thought there was some confusion over power vs. current. Again, I recommend this site: http://www.allaboutcircuits.com/vol_1/index.html . |
Nsgarch, you could have used a better example than an ESL. How about a B&W? ESLs are neither looking for current or voltage- they are expecting constant Power. That is why tube amps generally sound better on them too, so long as they are able to make the constant power into all frequencies. The idea of constant voltage appears to have nothing to do with the way we hear. Its odd how it keeps showing up. |
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