2. tech-talk
  3. 159496-5063

Help with blown tweeters/power issue

All,

Last night I was happily listening to my new speakers - the largest audio purchase I have or ever will make - when my amplifier’s display  blinked on and off, AirPlay cut in and out, and then wham - the volume jumped up to max with no input from me.  
I immediately shut off the amp, but I fear the damage is done.  The speakers and amp still make sound, but all I hear from the tweeters is a soft, high-pitched hiss. I assume they are blown, and I have no idea what else could be wrong inside the cabinets. 
I have no idea what happened.  My only thought is that the dryer was on nearby and could have caused some sort of voltage spike to the amp.  When I turn on a nearby dehumidifier the lights dim momentarily, which makes me suspicious there is some power issue at play.
I have two questions:

1. What do I need to do to assess the full extent of damage to the speakers?  There are no dealers nearby. 2.  How can I prevent this from happening again?

Thanks for any help.  This has been an awful experience. 
128x128lousyreeds1
mijostyn's avatar
mijostyn
8,570 posts
 
If you hear a hiss in your tweeters they are still working. A bad tweeter will generally give you no sound at all. The failure mode you mention is really unusual. An amps volume does not go through the ceiling without help from something, a tripped switch to a program source with more gain. You can get a test CD with a frequency sweep that will tell you instantly if any of the drivers are blown.
You could put a surge protector on the system but I am not so sure this was a power issue. 
lousyreeds1's avatar
lousyreeds1 OP
286 posts
 
All,

Many thanks for the insight. 
If you hear a hiss in your tweeters they are still working. A bad tweeter will generally give you no sound at all.
If I'm hearing a hiss through the tweeters but no other sound, what does that mean for likely damage?  The crossover?  Something is clearly wrong.  
To assess this remove the tweeter and hook it up directly to the amp. Full range will not damage a tweeter, if the volume is low, so if it is still good you will know, it will sound like its getting a full range signal. In that case its crossover damage. Which is unlikely. Almost certainly the tweeter.
I'll try this tonight.  
You could put a surge protector on the system but I am not so sure this was a power issue.
Everything was plugged into a surge protector.  It very well may not have been a power issue, but I can't imagine what else could have caused this.  The amp now appears to be working completely fine.  

lousyreeds1's avatar
lousyreeds1 OP
286 posts
 
All,

For those who enjoy a bit of humor or schadenfreude, here's where this turned out.  

I was able to recreate the problem, which as some of you suggested, had nothing to do with power issues.  It was a simple network glitch with AirPlay - I had held down the volume up button on my phone for too long when it didn't initially respond, and when it did, it skyrocketed to max volume.  A simple app update solved the problem.

And having run a number of frequency sweeps on the speakers and played a lot of music, it appears the woofers, tweeters, and everything else are in fact fine.  No harm done.  The hiss from the tweeters is just a bit of AC noise.  

So this was a network malfunction combined with audio nervosa on my part - all is well.
More to discover