wrote:



OK - a few basics on speakers - at least as they were sold in the
US under FTC regulations (sit on your fingers, Phil!):


** The are simply no FTC rules for published speaker power ratings.
The rules you seem to be alluding to are for *amplifers* used in
home entertainment.


Let's clarify, then. US speaker manufacturers very rapidly adapted to the FTC rules when publishing their ratings. Prior to these rules, IPP was the way amp makers would fool their buyers, and speaker makers would do their ratings similarly. As things equalized, their ratings became much more realistic.

** Entirely different to the nonsense you posted before.

The "rated power" of a hi-fi speaker is generally the largest amplifier power rating that it is acceptable to use with music program. This number is however many times greater than the continuous (ie sine wave) power handling of the same speaker.


What can happen with some solid-state designs is that when the
amplifier clips (called to produce more power than it can),
it may send straight DC into the speaker

** Absurd.

Clipping does not cause DC, the main effect is to compress the
dynamic range of the music so there is more average power going
to the speaker - which eventually overheats the voice coil.



If you can, next time you are out on the street, see if you can borrow either of a Dynaco ST80, ST120, AR amplifier, any of several Scott/Fisher/Sherwood solid-state designs, any any of many pacific-rim solid-state designs that used discrete output transistors, a Revox B722 - the list goes on. Drive it to clipping. At clipping you will see serious DC at the outputs. This will 'freeze' the VC(s) in one position with lots-O-energy at the same time.


** You are still equating peak clipping with steady DC, which is bizarre nonsense.

" Clipping does not cause DC, the main effect is to compress the dynamic range of the music so there is more average power going to the speaker - which eventually overheats the voice coil. "



Instrument amps blow speakers for many different reasons -
and even a transformer will transfer chopped DC.

** Chopped DC has both DC and AC components.

Transformers can only "transform" AC current while any DC current is converted to heat in the primary winding and magnetises the iron core.
No DC appears at the secondary.



.... Phil