Low damping factor but fast& high current SS amps?

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Liguy, did you cut and paste that from a tech for dummies web site?

I think it is a rather poor explanation because it is the magnetic field which damps the motion, not back EMF.

The amount of force it takes to move a generator (ringing speaker in this case) is proportional to how low the load is.

The lower the impedance the speaker sees looking back into the amp the more current it generates with its motion.

The more current it generates the stronger the magnetic field it generates which pushes back against the speakers magnetic field.

That's why speakers are often shipped with shorting straps across their terminals. This short allows a lot of current to flow when the speaker vibrates and dampens it. If you ever turned a hand generator you will find that the harder you crank and the lower the load the harder it gets. Not because of any back EMF, because the magnetic field from the current flow pushes back.

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Electricity and magnetism are interchangeable.

Not at all, they go hand in hand but are entirely different beasts. It is the magnetic field generated by the current in the coil that is pushing against the speaker magnet that dampens the motion.

Something is pushing the coil in a direction opposite of the way it is traveling and that force is magnetic. There is no way to logically explain the phenomenon using back EMF. Back EMF is not pushing the speaker.

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In a dynamic system, I rather doubt you can have one without the other.

It is very easy to have EMF without a magnetic field. Voltage without a path means no current. No current means no magnetic field.

Since the impedance is very low the current is higher and the EMF very low (ohm's law). Again, it is the field created by the current doing the work, not EMF.

I'm not too uncomfortable calling it back EMF

Comfortable or not, it is wrong. EMF is voltage. It is not voltage that damps the motion, it is a magnetic field.

This is physics. There are precise definitions for these terms and the science behind how they interact is well defined and understood. Since you are comfortable using them incorrectly there is no point in further discussion.

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Kirkus, good point, I didn't occur to me that somebody might be confused if they picked the incorrect meaning of EMF.

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Sorry

I just thought maybe you had since it is exactly the same wording in this Crown paper.

http://www.crownaudio.com/pdf/amps/damping_factor.pdf

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