wrote:
Here is a new twist in the debate about clipping damaging tweeters.
** It's not new and there is no such debate going on.
Its in this excellent book.
http://milas.spb.ru/~kmg/files/liter...Amplifiers.pdf
Designing Audio Power Amplifiers
by Bob Cordell
On page 332 re protection circuits.
If V-I limiters only acted to clip the signal amplitude, as with ordinary clipping of
an amplifier, they would not be so bad. Unfortunately, in most cases the V-I limiter
causes the output stage to change from a voltage source to a current source when the
V-I limiter engages. When this happens, there is almost surely a lot of stored energy in
the loudspeaker and crossover network. This stored energy wants to cause current to
flow somewhere and be dissipated. With the output stage in a current source mode of
operation, this may not be possible. As a result, a large inductive spike or kick may
result, often transitioning the output voltage to that of the opposite rail (i.e., in a direction
opposite to that in which the output stage was changing the signal).
This spike will be very audible, and its large amplitude may cause damage to the
loudspeakers tweeter. The action of a V-I limiter can turn an amplifier into a tweeter
eater. The stored energy in the loudspeaker drivers and crossover will find its way to a
place where it can be dissipated. The stored energy in the woofer and crossover coil(s)
may be transferred to the tweeter.
** Bob's book is Copyright 2011
In 2000, this article was published on the ESP site.
http://sound.whsites.net/vi.htm
The text accompanying figure 4 covers the same issue.
So it may be the transients created in some protection circuits that
actually damage the tweeter, not simply clipping.
** No fooling ?
That heavy amp clipping harms (unprotected) tweeters is beyond dispute, the transients do it theory is full of holes.
This is the first thing that I have read about this subject that
actually makes some sense.
** Strange how things make sense to you and not others.
..... Phil