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Why (and how) do Tweeters die?

Sloop John B

Sloop John B

And any old music will do…
One of the tweeters in my SL2s has ceased to be, an ex-tweeter as it were.
I didn't notice any major occurrence (one sees mention of tweeter blowing) and with my high frequency hearing loss I don't really know how long it has been demised.

Why do tweeters cease to be and do they do it slowly over time or is it just a keeling over event.

I really know so little abut how any of this works, but I know you lot do...........................

.sjb
 
It is an electro-mechanical device. So does not have an unlimited life. But I would not expect a gradual decline unless it is ferrofluid type and it had been losing it slowly.

Yes you can overdrive it (I have destroyed some that way many years ago as a student), or it could die of fatigue and old age.

Coil open circuit is an obvious thing to check. If the coil is not open circuit, then it could, I guess, be mechanically jammed somewhere. In that case rescue may be possible.
 
I’m sorted with the tweeter I’m just interested in what might have happened and over what time period.
I’d say mine has died of fatigue from what you’re saying.

still unsure of what exactly died though.
What was working that stopped?

.sjb
 
Not a tweeter, but these .gif illustrations of how a loudspeaker driver works are a good start.

loudspeaker.gif

magnet.gif

suspension.gif

sound-waves.gif
 
And how do you know, you have fatigued tweeter or crossover? Do the speakers sound dull in both cases?
Excuse the thread hijack, but I guess it's somehow connected.
 
The sl2 have quite a low xover point for the type of hf unit used and eventually the suspension bridging braid breaks.
 
Ferrofluid was probably the worst idea, the great culprit, rendering many speakers impossibly dull because the fluid hardens with age, thus seizing the coil.

Getting rid of the fluid - when it's possible - restores treble energy.

I've also had alnico tweeters partially demagnetised (Celestion HF2000).
 
When my DBLs were active I got through quite a few tweeters, but then I do like "realistic" listening levels. Always keep a spare or two...

Being decrepit myself, I don't immediately notice their demise, but the difference, when you replace them, is quite astonishing, and not just in the treble.
 
chartz said:
Ferrofluid was probably the worst idea, the great culprit, rendering many speakers impossibly dull because the fluid hardens with age, thus seizing the coil.

Getting rid of the fluid - when it's possible - restores treble energy.

I've also had alnico tweeters partially demagnetised (Celestion HF2000).
Click to expand...

Just to clarify before anyone gives it a go, you can’t just remove the ferrofluid from a tweeter that’s designed to use it.

As well as damping. It also provides cooling for the voice coil, so you’re likely to burn out your tweeter even more easily if you try this!
 
Cane Jameson said:
Distortion is the enemy of the tweeter. I've killed 2 pairs with Sonic Youth
Click to expand...

I think you mean driving the amplifier into clipping. This usually happens with an underpowered amp. Clipping puts a lot more power into the tweeters and can fry them.

Cheers,

DV
 
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On a tweeter, the wires connecting the voice coil to the outside world are very thin. These wires are subjected to constant vibration when the driver is working and can fail easily if the driver is over driven. Most of the time when a tweeter dies that's what it is, the lead out wire has snapped.

It's almost inevitable that they'll go eventually because they're so thin. Bass and mid drivers use heavier wire, often braided wire, so they're much more robust.
 
I blew one on a mission 700 back in 1985 by overdriving with too weedy an amp.

Recently when I went to set up my NBLs in a new place I couldn’t get the image to centre. My stand in Thiels do this easily and back in my old house the NBLs out imaged the Thiels. The outboard crossovers made diagnosis easy even without an avo. There are a also couple of new minor dings (only noticeable by the different paler colour next to a couple of pre-existing ones) on the cabinet of the offending speaker, which was wrapped and moved by a removals company as I don’t have the boxes. I’m expecting to struggle with the claim I’m just about to put in to the removal insurance for a matched pair from Naim at 4 x the price of two of the same model tweeters from Scanspeak.
 
What Sjb has described has happened to me. In a way.

I had a pair of Royd RR3's stored in the basement for a couple of years. Atfer a move I started using them again. Strange, now they sounded VERY dull. It turned out that the output from booth tweeters was rather low, something lik 10 dB. If they had been fried, they should be completely quiet.
No problems with the bass drivers. Hmmm?!? In the end I ordered a pair of new ones from a Brittish DIY supplier (their stock was running out, btw). Installed them and everything sounded as it should.

So, what might be the cause? My guess is that the tweeters use neodynium magnets that, while in storage, has been demagnetized. Somehow. The woofers use good old cheramic magnets.

But the Scan Speak ones Naim used isn't neodynium, are they?
 
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