J=sigma*E (sometimes called generalized Ohm's law) where no assumptions is made about sigma (can be a function any number of variables, including V) was eventually introduced, following Ohm, if memory serves, by Kirchoff.
It is not part of the fundamental EM field Maxwell equations, in either microscopic, macroscopic or covariant formulations. However, it is fundamental in any approach to study charge transport, being as fundamental as D=eps*E or B=u*H. Materials with sigma, eps, u all constant (so J=sigma*E is exactly the Ohm law as S7*10^3 loves to believe) are usually called LIH (Linear, Isotropic, Homogeneous) materials, a pretty rough approximation in many cases.
The three material laws above are not the consequence of any more general EM field laws (at least in the frame of the Maxwell theory). They are all postulated and therefore independent.
Whether to consider R=U/I the one and only "Ohm law" is kind of a personal option. I don't, and prefer to call J=sigme*E "Ohm law" and think of the R=U/I as a local version of the Ohm law (that is, in an infinitesimal small vicinity).
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Yes, I stated exactly this quite a few pages back.
Yes, but no return energy means no return energy, thus amplifier type becomes essentially irrelevant. Speaker flatter FR for high output resistance amplifier is a bonus in addition to the improved clarity due to removal of amp/cable/speaker circulating energies.
Yes, the return energy is transduced in the RC resistor and converted to heat. (a perfect short cannot convert electrical energy to heat energy) The usual situation is that the amplifier has to deal with this return energy, my experience is that amplifiers sound cleaner and run cooler with resistive load/no return energy.
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Yes, the loudspeaker assy (drivers/crossovers/networks) absorbs all energy presented to it and none is returned back to the amplifier..
The drivers do return the voice coil magnetically stored energy but this is passively 'caught' in the RC networks and prevented from traveling up the speaker line and being 'synthetically' caught in the amplifier output stage. IOW excess energy circulates between drivers and networks and is dissipated in the R component of drivers and networks and so no return energy gets to the amp.
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Just happen to have those in stock! R>C from + side? + 6r>0.47uf -
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The order of the R and the C is not critical, just keep both channels the same/identical...maybe modifying one channel only is best for initial test/comparison purposes.
With those external crossovers with twist connects this should take you but a few minutes, let us know what you find.
With those external crossovers with twist connects this should take you but a few minutes, let us know what you find.
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No. Repeating Joe's idea in your own words does not make them become true.Max Headroom said:
The relativistic version of Ohm's law (which I don't remember seeing before) still assumes proportionality/linearity.PMA said:
D=eps*E, B=u*H are not very fundamental. They are similar to Ohm's law in that respect, being summaries of how some materials behave.syn08 said:
I never realised that there was so much confusion about such a simple point. Ohm's law is true for ohmic materials. An ohmic material is one for which Ohm's law is true, to a considerable extent i.e. voltage and current are approximately proportional. A non-ohmic material is one for which Ohm's law is not true. If, as some seem to be saying, Ohm's law is simply an equation with a ratio which is not necessarily constant then how do you define ohmic? Ohm's law becomes a name for an equation instead of a name for a common phenomenon. Maybe people have misused this name for so long that now the new usage has become accepted as the correct usage? I was never happy with this approach to language, as it legitimises confusion.
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