-- Why LSi Tweeter fried like this? --

[MKZ]

http://i51.photobucket.com/albums/f371/zinm/LSi/DSC04191.jpg

[McLoki]

Any idea what was happening when it did it? (playing loudly, just turn the amp on or off, etc.)

[treitz3]

Good gawd, man! Where are your treble settings?

[george daniel]

Good gawd, man! Where are your treble settings?


What is a "treble" setting? Is it something like a "tone" control? ;)

Seriously,,, were you cranking that bad boy when it happened? Receiver?
Good luck.

[BaggedLancer]

Good lord, looks like one of a pair that was on an ex-girlfriend of mine.

[MKZ]

I just got my B&K back and try to turn it back on and found like this. It had loud buzzes before. I just want to prevent it from happening again.

[Keiko]

Good lord, looks like one of a pair that was on an ex-girlfriend of mine.
Waaaaaaaaaaa...LMFAO! :D

Afraid to ask what the other one looked like. ;)

[Face]

That's impressive.

[treitz3]

Do you know whether this happened before the repair or when you got it back from repair and turned it back on?

[MKZ]

The other one looks good but no sound.

http://i51.photobucket.com/albums/f371/zinm/LSi/DSC04192.jpg

[Airplay355]

Very upsetting. I hope you get it all figured out!!

[treitz3]

Most likely from the looks of things the speaker with the good tweeter that has no sound has an unsoldered contact somewhere. Most likely due to an extreme amount of current going thru it, melting the solder.

Did any noise whatsoever come out of each speaker the moment you hooked all back up and turned it on?

[MKZ]

Do you know whether this happened before the repair or when you got it back from repair and turned it back on?

After repaired. They just update the firmware version nothing more.
No noises or any other unusual happened after turn it back on.

[dkg999]

Did they per-chance replace an output transistor and bias resistor on your B&K? If yes, potentially pure DC being output to your speakers when the buzzing was occuring.

[MKZ]

Looks like the solder joints are in attached to me.

http://i51.photobucket.com/albums/f371/zinm/LSi/DSC04193.jpg

http://i51.photobucket.com/albums/f371/zinm/LSi/DSC04194.jpg

[MKZ]

Very upsetting. I hope you get it all figured out!!

It is. I still have some ICs to try it on are waiting.

[McLoki]

Do you have a multi-meter? If so, disconnect your speakers - turn on your amp (and pre) and see if you are getting DC voltage to the speakers. (although if it was DC, I would expect the woofer to fry before the tweeter, then again - maybe it has)

Michael

[MKZ]

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=264-555

Is that one from Parts Express the same tweeter?
Polk tweeters are the bulk version of this?

[McLoki]

How much is a Polk LSi tweeter? Personally - I would go ahead and source the correct replacement. Not having the correct tweeter could hurt resale more than the cost difference, and if anything does not sound right in the future - you will always wonder if it was the tweeters fault. (or at least I would.)

Hard to look at the outside of anything electronic and know what is really on the inside.

Michael

[MKZ]

I just remembered that I did connected the CD player directly to the Amp with multi-channel out to find out the Pre fault or not after having the loud buzz. I think its play fine that time. Is that why the tweeter got fried? I noticed too much gain from Player and had to turn down the volume knob on Amp.

I preferred the OEM but I saw some members recommending those Parts Express Tweeter for replacement so just wondering.

[zingo]

I have heard that the Polk version of the tweeter is a little different than the stock/PE version.

Good luck with your tweeter, but man is that impressive!

[MKZ]

The Polk LSi Tweeter costs $100/each plus shipping so I can't afford to fry like this as soon as I hook up.

Is that time to try another speakers?
I love LSi series especially for those very detailed tweeters. The woofer are not that impressive. IMO.

[ohskigod]

dude, you might have a gear issue to figure out before moving to another speaker. I;ve had my LSi's LOUD and never had that problem.

amp issues, amp clippiung. its distortion of some kind causing that, new speakers wont help, there is an issue up the stream somewhere.

[Face]

I just remembered that I did connected the CD player directly to the Amp with multi-channel out to find out the Pre fault or not after having the loud buzz. I think its play fine that time. Is that why the tweeter got fried? I noticed too much gain from Player and had to turn down the volume knob on Amp.I have a CDP with adjustable output gain. Running it at full would have definitely destroy something here.

[dkg999]

And now we have "the rest of the story"! Good day!

[ohskigod]

DOH!,

I missed that part.

thats could DEFINITLY be it. its alright, I've learned lessons the hard way myself.

[MKZ]

Sorry, I'm kinda lost here. Which one? the one that Face mentioning?

[dkg999]

Yes! It certainly has the potential to cause that sort of catastrophic damage.

[zingo]

Do you have a cheap pair of speakers or single drivers that you can hook-up to the amp and see if the same thing happens? A local audio shop also might be able to take a look at the amp for a small price to see if it is the problem. Ruling that in or out would be a huge step forward in this puzzle.

[MKZ]

I have swapping out with my other amp and speaker.
with other amp, same speaker, no sound from tweeter.
with other speaker, same amp, it sings.

[MKZ]

Yes! It certainly has the potential to cause that sort of catastrophic damage.

Thanks. Now I can start changing the tweeters.:)
I have learned the hard way and never ending.

[cfrizz]

Talk about learning an expensive lesson!


I just remembered that I did connected the CD player directly to the Amp with multi-channel out to find out the Pre fault or not after having the loud buzz. I think its play fine that time. Is that why the tweeter got fried? I noticed too much gain from Player and had to turn down the volume knob on Amp.

I preferred the OEM but I saw some members recommending those Parts Express Tweeter for replacement so just wondering.

[nikolas812]

It's just a guess but I would assume both tweeters are fried. Just because it doesn't look melted down like the other one doesn't mean its good. In fact I have never seen a bad tweeter change form like that one. Way to go. Thats awesome.:D:p

Pick up a couple new tweeters. or better yet. Send your speakers to Polk for a check up. That would be your best bet.



Nick

[MKZ]

You wouldn't believe that the TECH from both B&K and AudioAdvisor want me to try connect the cable directly from source to Amp while I was having the buzz problem.

[Hawkeye]

You wouldn't believe that the TECH from both B&K and AudioAdvisor want me to try connect the cable directly from source to Amp while I was having the buzz problem.

Actually, that is not bad advice as long as you turn the power off before moving the cables. I have run my CDP directly to the amps with no pre in the middle. I was experimenting and found the sound to be very sterile without the pre. If I had liked the sound, I would not think twice about running the source directly to amp. It is also a good way to eliminate the pre as a cause of noise.

Gordon

[danger boy]

to me it seems like it's the amp that fried your tweeter.. with some kind of DC current reaching your speakers.

[treitz3]

I just remembered that I did connected the CD player directly to the Amp with multi-channel out to find out the Pre fault or not after having the loud buzz. I think its play fine that time. Is that why the tweeter got fried?
There's your answer. That's the same thing as turning the volume all of the way up to test. What you see is the end result of what overdriving your components and clipping will do to a speaker.

[treitz3]

Actually, that is not bad advice as long as you turn the power off before moving the cables. I have run my CDP directly to the amps with no pre in the middle. I was experimenting and found the sound to be very sterile without the pre. If I had liked the sound, I would not think twice about running the source directly to amp. It is also a good way to eliminate the pre as a cause of noise.
IF you have a variable out on the CDP.

[george daniel]

IF you have a variable out on the CDP.



key word "if",, and then you better know what you are doing,,,even on low volume a cdp direct to an amp may surprise you. Good advice Tom,,, been there done that :)

[Hawkeye]

IF you have a variable out on the CDP.

You're right. I should have clarified that point. I misread the post and thought he had a gain on the CDP which after reading again there is not. That's what I get for posting after a 12 hour shift.

Gordon

[heiney9]

I would first and foremost check for DC at the amp outputs. That tweeter got extremely hot; hot enough to deform the diaphragm. Why the fuse or thermistor didn't blow is anyone's guess.

Are the speakers under warranty? At the very least I'd send them into Polk (the x-overs) and make sure nothing else was damaged. Start with the amp as that has the most potential to do the kind of damage you see.

I still don't quite get how/why/you hooked and unhooked stuff.

H9

[GV#27]

I would first and foremost check for DC at the amp outputs. The series cap in line with the tweet should block any DC sourced from the amp.Another posiblility is that the cap actually shorted allowing low frequencies to leak through.If thats the case it would very quickly overheat and be forced to do some extreme over excursions.:eek:

[Face]

I doubt it was a bad cap if both tweeters no longer work. That must have been a lot of juice going to them! :D

[MKZ]

Should I send the Amp back for service? I bought LSi7 used here and it showed the sign of that tweeter has been changed by the previous owner.
I'm thinking about to get new speakers and I really don't want to get fried like this.

[Face]

Did you test the amp for DC? There may be nothing wrong with it and the way you "tested" for hum may have done all the damage.

[GV#27]

I doubt it was a bad cap if both tweeters no longer work.Nope a bit to coincidental ,I didn't see that part about the other not working.But if he hooked up his CDP directly to his amp as a precaution I would be checking through those crossovers for damaged caps before installing new tweeters.
I know its a stretch but it may have opened the cap on the side not working and shorted the one with the destroyed tweet?

[Deadof_knight]

hmmmm it looks melted too me TOOOO much heat, that what causes that, from the pic the open connectors are contacting the magnet assembly in any way are they ?

[Shannon W.]

Look on the Cross over on the other speaker that looks fine but don't play and see if it looks like this.

http://i157.photobucket.com/albums/t52/Imlow78/DSC00732.jpg

http://i157.photobucket.com/albums/t52/Imlow78/DSC00731.jpg

http://i157.photobucket.com/albums/t52/Imlow78/DSC00730.jpg

http://i157.photobucket.com/albums/t52/Imlow78/DSC00729.jpg

This is what happened to a one of my LSi9's. The warranty was out so I re-soldered the broken connection and BINGO my tweeter was playing again. Noting was wrong with the speaker I think it was a poorly soldered joint from the factory. But I fixed it myself and after that I never had a problem after that. (Even when I hook all my LSi's up to my new Sunfire Amp.)
Shannon

[awe-d-o-file]

Roasty toasty........DC from a clipped SS amp will do that.