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- Newsgroups: sci.electronics
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!sample.eng.ohio-state.edu!purdue!yuma!gw214790
- From: gw214790@LANCE.ColoState.Edu (Galen Watts)
- Subject: Re: Switching speakers on during loud volumes
- Message-ID: <Dec15.214844.78377@yuma.ACNS.ColoState.EDU>
- Sender: Galen Watts, KF0YJ
- Date: Tue, 15 Dec 1992 21:48:44 GMT
- References: <Bz6nyz.LF4@acsu.buffalo.edu> <sehari.724447297@class1.iastate.edu>
- Nntp-Posting-Host: blanca.lance.colostate.edu
- Organization: Colorado Concert Sound
- Lines: 30
-
- 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
-
-