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Help!!! I keep blowing tweeters in my AR4X after Recap.


Guest orionkc

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Guest orionkc

This is really getting old. Only having problem with one speaker. I recapped with 20uf Solens and one of the speakers keeps blowing tweeters.

At first I thought the original tweeter was bad so I got another one and installed it and it blew too. I then had another tweeter laying and installed it and it worked for about 10 minutes and it blew. What could possibly be wrong? I'm running out of tweeters.

Thanks,

Rick

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>Also, just to be really safe, add a fuse in series with the

>tweeter as recommended by Vern (check out the 'other' threads)

>for fusing topic.

When a good mechanic sees a blown fuse, he asks "why?" I would follow Carl's advice and trace the circuit for a wiring short circuit, bad capacitor, etc. Is the amplifier misbehaving?

Cheers,

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Assuming that the wiring is correct and the capacitor is OK, there is another possibility and that is that your amplifier has a high frequency (ultrasonic) parasitic signal being fed to the tweeter. You won't hear it but it's real and it can blow out tweeters. People who use some exotic speaker cables can risk this by inadvertently creating a "tank" circuit (oscillator) in the output stage of their amplifiers. There are other possible causes including a defect in the amplifier itself, a defect in an input device, or some type of inductive or capacitive coupling to whatever is generating it. Even a power supply defect can cause it. The only way to know this is with an oscilloscope. Capacitors which appear to function correctly at low voltage can break down and arc over internally in use, then appear normal again when tested with a capacitor checker. This would cause the tweeter to fail in use also. Also verify the impedence of the voice coil of the tweeter with an ohmmeter. I suppose there's a one in a million chance it is mismarked.

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>Assuming that the wiring is correct and the capacitor is OK,

>there is another possibility and that is that your amplifier

>has a high frequency (ultrasonic) parasitic signal being fed

>to the tweeter. You won't hear it but it's real and it can

>blow out tweeters.

If both speakers have the Solen upgrade, then both would likely be vulnerable to an amp issue and yet the same speakers is the problem. That suggests to me the problem is with the speaker, not the amp.

People who use some exotic speaker cables

>can risk this by inadvertently creating a "tank"

>circuit (oscillator) in the output stage of their amplifiers.

>There are other possible causes including a defect in the

>amplifier itself, a defect in an input device, or some type of

>inductive or capacitive coupling to whatever is generating it.

> Even a power supply defect can cause it. The only way to

>know this is with an oscilloscope. Capacitors which appear to

>function correctly at low voltage can break down and arc over

>internally in use, then appear normal again when tested with a

>capacitor checker. This would cause the tweeter to fail in

>use also.

This is also why I suggested changing out the cap with another one.

Also verify the impedence of the voice coil of the

>tweeter with an ohmmeter. I suppose there's a one in a

>million chance it is mismarked.

It's all about the music

Carl

Carl's Custom Loudspeakers

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>This is really getting old. Only having problem with one

>speaker. I recapped with 20uf Solens and one of the speakers

>keeps blowing tweeters.

>

>At first I thought the original tweeter was bad so I got

>another one and installed it and it blew too. I then had

>another tweeter laying and installed it and it worked for

>about 10 minutes and it blew. What could possibly be wrong?

>I'm running out of tweeters.

>

>Thanks,

>

>Rick

Rick, when you say the "speakers keeps blowing tweeters", what exactly do you mean?

How do you know the tweeter is blown?

Regards,

Jerry

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Hi there;

I would suggest at the very least a 3/4 or smaller amp fast blow fuse to try out the next tweeter.

Normally I would say a 1 amp fast blow but in this case there is a problem and a $.50 fuse isn't too bad to sacrifice.

Soundminded may have struck a nerve with the problem.

This question needs to be asked.

Were you using the amplifier volume at a reasonable level each time?

If the tweeter on the same cable and channel keeps blowing, are the wires to the speakers concealed?

Can you see if there is a knick or cut in the cable which may allow a short, however minor?

Can the capacitance value of the cap be confirmed?

Maybe one in a million caps gets mis-marked, and this is not the lottery.

If you changed out both caps, one works fine, it is therefore highly unlikely you did something wrong with only the one, but Murphy's Law prevails.

When you have another tweeter and fuses, try changing the speakers channel for channel and/or if free, wires from left to right channels changed.

A very nice value and durable speaker system, sets the standard for bookshelf speakers, that is for sure.

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Guest matty g

Hi -

You might try hooking up a full range speaker to the tweeter leads (with the tweeter disconnected and out of the way)to hear if low frequencies are passing to the tweeter wiring. The full range driver should sound more or less like a tweeter. If it sounds like a regular speaker or if it sputters then you have a wiring/cap problem. Don't crank up the volume or bass too much as the cabinet isn't sealed during this test, and we don't want to damage the woofer. Bear in mind that this is just a crude test, and that you may have a more subtle problem such as an intermittent cap. Also work the pot back and forth while listening, see what happens.

Hope this helps

Matt

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Guest orionkc

>>This is really getting old. Only having problem with

>one

>>speaker. I recapped with 20uf Solens and one of the

>speakers

>>keeps blowing tweeters.

>>

>>At first I thought the original tweeter was bad so I got

>>another one and installed it and it blew too. I then had

>>another tweeter laying and installed it and it worked for

>>about 10 minutes and it blew. What could possibly be

>wrong?

>>I'm running out of tweeters.

>>

>>Thanks,

>>

>>Rick

>

>

>Rick, when you say the "speakers keeps blowing

>tweeters", what exactly do you mean?

>

>How do you know the tweeter is blown?

>

>

>Regards,

>Jerry

>

>

Jerry,

I tested the tweeters after they quit working with an multi-meter and get no readings. The tweeters were all working until I put the new caps in. I originally had a virgin set of ar4x's with one rotted foam woofer. I replaced the woofers and at the same time did the caps and started having the tweeter problems after that.

Can you visually see if a voice coil is bad or is the only way to find out to measure with the multi-meter?

On my multi-meter I turn it all the way to 6:00 which says 200 ohm and put the black lead to the common and the red to the positive. They usally read around 5.7 and the woofers are close to that also.

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Guest orionkc

>Try a different Solen, But, before doing that, check your

>wiring for shorts or to see if the Solen circuit has been

>bypassed somehow.

>

>

>It's all about the music

>

>Carl

>Carl's Custom Loudspeakers

Could I possibly have a cold solder joint when I replaced the caps?

Would that do it?

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>>Try a different Solen, But, before doing that, check

>your

>>wiring for shorts or to see if the Solen circuit has been

>>bypassed somehow.

>>

>>

>>It's all about the music

>>

>>Carl

>>Carl's Custom Loudspeakers

>

>

>Could I possibly have a cold solder joint when I replaced the

>caps?

>

>Would that do it?

A cold soldered joint would stop current from flowing rather than cause a short to the tweeter (e.g. bypass the cap). I don't think that's the issue.

Could you take a pic of the crossover area in the problem speaker and share it with us?

It's all about the music

Carl

Carl's Custom Loudspeakers

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>Jerry,

>

>I tested the tweeters after they quit working with an

>multi-meter and get no readings. The tweeters were all

>working until I put the new caps in. I originally had a

>virgin set of ar4x's with one rotted foam woofer. I replaced

>the woofers and at the same time did the caps and started

>having the tweeter problems after that.

>

>Can you visually see if a voice coil is bad or is the only way

>to find out to measure with the multi-meter?

>

>On my multi-meter I turn it all the way to 6:00 which says 200

>ohm and put the black lead to the common and the red to the

>positive. They usally read around 5.7 and the woofers are

>close to that also.

The multi-meter reading is one way to determine what's wrong with a tweeter. When you get no reading it means the tweeter voice coil is open.

When tweeters over heat all kinds of things can go wrong.

Rick, once you re-capped, did you play the speakers at high volume levels? It's hard to believe that new caps would cause the tweeters to fail, but I guess anything is possible.

No reading on your mulit-meter means that a wire is broken somewhere on the tweeter. Perhaps, Rick, if you look real close you can find the break.

Hope this helps ...

Regards,

Jerry

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