i had i big party last night that included some bad karaoke, to make a long story short i can't get any sound from my high range tweeters in either of my exl:26 floorstanding speakers, i get perfect sound from the center channel (also energy), and my sub is working fine, i checked my reciever with a old pair of infinty's and they sound fine as well, so i have pretty much narrowed it down to the 2 floorstanding energy's (exl:26), the problem is identical with both speakers. here is some background on the hook up from last night, i had a cheep karaoke machine hooked to my tv via rca cables (yellow video) L R ect. my tv is connected to my reciever via the same type cables (monster cables), we played the karaoke music in stereo all night and it sounded pretty good, and a few times some of the guys cranked the volume pretty loud and i heard some reverb or distrotion, anyways when i woke up this mourning i put in a music cd in my dvd player which only has a digital connection and now i am getting zero from my tweeters ,doesnt matter what dsp setting, dd,dts nothing seemed to fix it , my only guess is there is some kind of fuse or switch that i blew last night during karaoke nightmare.


please help

mark

Check your speakers to see if the tweeters are connected to circuit breakers. My mains do that to protect them from overload. Hit "reset" and you're back in business.

They may be internal, although you don't see that too often, so check your manuals too.

Mark, hopefully, the tweeters are protected, but it may be that they're not. When a transistor amp is driven into 'clipping', which means it's being asked to put out a higher voltage than it's capable of, the voltage waveform has a flat plateau, which is where the output transistors are at full conduction.

At the points where the waveform goes from smooth curve to flat top and flat top back to curve, and the wave looks like the top has been clipped off, there are sharp angles in the wave. These points generate very large bursts of high-frequency noise, as would any square-wave. Unfortunately, the tweeters receive this high-energy distortion and the result is overheating of the voice coil.

The sad result is burned-out tweeters, and the only fix is replacements. In the future, "Keep your cousin off the phone."

Larry
www.fineelectricco.com

You actually double the amount of power to your loudspeaker when you 'clip' the amplifier's input.

I've actually ran about 5 times the power into speakers than the rated power, but it was extrememly clean power no clipping distortion. It's hard to blow out speakers with too much clean power, but clip the signal and it won't take long!

i unscrewed the back plate where the speaker wire goes into the speaker and the voice coil thingy ma jig looks black down toward the the end so i am afraid you are right, does this sound like something that is covered by warrenty or am i just out of luck and 700 bucks

Mark; RE: warantee: I'll share a story.

I was in an a/v shop a while ago & a fellow was talking to the rep & he was telling the rep that his pup had chewed on the speaker wires & he heard a ZZZT
noise & replace the wires & the recvr still doesn't work on that channel - reps answer - "no warantee". When the fellow left I asked the rep what if he had just said it is making a wierd noise & left out details?
rep said - "covered".
So I think it depends on BRAND, WARANTEE SPECIFICS, STORE, & LEAVING OUT GRAPHIC DETAILS?
Dougofthenorth

Well, I'm pretty sure you could buy just the tweeter from the manufacturer and if it's matched then you'll need to get the serial number off the back of another driver (in some cases).

'When you hear distortion, turn it down' -Matt

An electronic compressor was definately in order.

A compressor does just that, it compresses, or lowers the output of the microphone to a preset level. Adversely, it will raise the output when people have "weak" voices.

That's why professionals use compressors to eliminate tweeters being taken out. People who "SCREAM" into the microphone can overdrive the output, which always takes out tweeters first. (Because they have the smallest voice coil of the speaker system)

JJP

Actually, radio station announcers use a type of compressor called a 'limiter', which prevents overmodulation, but doesn't boost softer sounds like a linear compressor does. (The linear compressor is used by dbx noise-reduction circuitry, at a 2:1 compression, and a 1:2 expansion. A single device that does both is called a 'compander' [compresor-expander]) It's also why DJs sound so alike; the 'timbre' is all but lost.

Tweeters don't suffer the most because they have smaller voice coils, the suffer because they get the high-frequency harmonics caused by the square-wave-shaped clipped signal caused by over-driving an amp. An amp doesn't have to be overloaded in the 'too much power' sense, because clipping even occurs with NO load; it's purely a voltage phenomenon.

The only effect trying to draw too much power has is a lowering of the power-supply voltage (from voltage sag) when overloaded, which causes clipping at a lower voltage than would occur otherwise. Actually, this kind of clipping is 'softer' than the purely over-voltage (output transistor saturation) kind, which causes the most tweeter damage.

Larry
www.fineelectricco.com

A compressor will not raise the level (unless it has an AGC circuit), you would need a downward expander for that, but now were just talking squashing the dynamic range of the system....my advice is DON'T run karoke through a home theater system.

Hi Mark,

One other piece of advice, I would never let anyone control the volume on your equipment again :) Personally, I spent too much money on my system to let anyone else play around with it. Thank God that I am fortunate enough to have an amp that sends loads of very clean power to my speakers. Not too mention that my Amp will automatically shut down the particular channel on clipping....Tony