On 10/09/2010 08:47, Andre Jute wrote:
Paul G asks:
"[W]hat is the best way to protect a
speaker from destruction if the amp is sufficiently powerful, and you
have no control over volume? It happens.... the kids have fun with
your stereo, the grounds come loose on the inputs (huge buzz), the
system oscillates, etc."

I don't know if you want to design and build your own stuff from
scratch, Paul, or merely want to buy a plug-in protector. If you can
solder, here's a halfway house in a couple items to protect your
loudspeakers from switch-on pops and from DC.

Velleman K4700 Loudspeaker protection kit, stereo with switch-on delay

Velleman K4701 Loudspeaker DC-protection, mono

The reason I've identified them is that I have a QUAD 405 MkII which
occasionally eats an ESL-63, which soon gets expensive, and it is
tricky rebuilding them because here is no way to solder except over
the fragile panels... So an audiophile's fancy turns to ripping out
the 405's inadequate clamp circuit and replacing it with industrial
strength protection.

I would fit a sensor that detects the onset of ionization and instantly
shorts the input to ground with a triac.
And maybe a soft-clipping circuit that works a few dB below the shutdown
level.
I can't think why Peter Walker didn't think of doing it....

--
Eiron.