🚀 go-pugleaf

In article <sehari.724447297@class1.iastate.edu> sehari@iastate.edu (Babak Sehari) writes:
>In <Bz6nyz.LF4@acsu.buffalo.edu> v064mb9k@ubvmsd.cc.buffalo.edu (NEIL GANDLER) writes:
>> I am designing a device that disconnects a pair of speakers from a
>>stereo recevier when the phone rings. But when the phone is eventually
>>hung up m afraid that suddenly switching back a pair of speakers with a
>>relay during high volumes can sort of "overwhelm" a pair of
>>sepakers and could in fact in the long run cause damage or destroy
>>them especially the woofer. Can someone confirm this. I would appreciate
>>any help. Thanks
>Put a low pass filter before your speakers.  That is find out what is
>the highest frequency of your speaker, then design a low pass filter
>that does not let higher frequencies damage your speaker, at the same

I would strongly suugest NOT putting in a lowpass.  The crossover in the
speaker will protect the woofer.  The low pass filter may cause strange 
things to happen to your freq and phase response.

It would be better to put a relay in one of the tape monitor loops (or inside
your preamp in the signal line, but only at hi-impedance points) that needs a
manual reset, so it doesn't blast back on when you hang up.  

The only problem with switching back on from dead silence is if your amp has
DC in with the speaker level signal.  DC will cause a wide spectrum pulse
(otherwise known as a "click")  that may blow your tweets, crossover caps, etc.
Otherwise, (no DC) switching on is no worse than a big transient in the music,
like power chords, kick drum, screams.....

Good Luck,
Galen Watts