From Sanders' paper:
"In a capacitor, the impedance is inversely proportional to frequency. So an ESL will have a high impedance at low frequencies, and a very low impedance at high frequencies -- typically 2 ohms or lower."
This implies that you have to deliver larger amounts of current at higher frequencies, BUT, look at musical content. The RIAA curve for LPs was developed because high frequencies would get lost in noise if they were not boosted prior to being recorded, i.e. the voltages for music at higher frequencies are lower, so you do not have to deliver as much current. I imagine that even at full blast a triangle does not need much current.
JonFo said:
.....Sorry, that's incorrect. It's the ESL's that are current driven.....
But from Sanders' paper: "ESLs are voltage operated devices".
Typically voltage-operated devices (e.g. preamps) do not require large amounts of current. Note: I am not saying that they do not require current, just that it is not as large as is implied in the paper when you consider the musical spectrum.
I used to be quite happy driving my Quad ESL 57's with only 25 watts/channel (Bedini SS Class A), until I tried a grotty old Dyna ST-70 with 30-year old tubes, but that's another story......I never looked back.
I have one basic problem with the concept of using skinny wires with anything that pushes large amounts of current - skinny wires have high resistance, so part of the signal gets dissipated as heat.