Best way to Protect Tweeters?

[Sancho]

I've read a number of things, the one Im most interesed in is the idea of fusing the tweeter leads. What is involved in this? Has anyone done it as a retrofit? I know some speakers came this way stock, I want to protect my investments Thanks for your help and I apoligize if this should be in the DIY forum.

 

[Cosmos]

Sure, you can put a fuse in line with the tweeter, but that is absolutely no guarantee against frying a tweeter...

The surest way not to damage a speaker is to make sure you don't take an amplifier into "clipping"

 

[dr*audio]

The inline fuses and circuit breakers don't protect the tweeters very well. I have replaced many tweeters in systems that had the protection. Best thing you can do is leave the bass and treble controls flat on the amp. When you boost the bass you are demanding more power out of the amp for all the bass frequencies. That would be ok if music was constant but it isn't; it has peaks and valleys. The peaks in the bass are multiplied by how much the bass control is boosted. It doesn't take much for heavy bass or a drum kick to be boosted to a level that is above what the amp can put out. When this happens it causes alot of distortion, which is mostly high frequencies. This goes right through to the tweeter, and this is how people blow their tweeters. I have speakers that are 40 years old with the original tweeters in them. Why? Because I keep the tone controls flat and don't turn the loudness switch on. I can listen at very loud levels without damaging the tweeters because I am not artificially boosting the bass beyond what the original recorded sound was.
Another thing you can do is buy an amp or receiver with plenty of power so it doesn't distort on peaks. 150 watts per channel should be enough.

 

[ToTo Man]

another thing to do instead of fusing is to hook a power meter upto your amp so that you can clearly see how many watts you are using

 

[M Jarve]

Ultimately, you want to make sure your amplifier is capable of reproducing sound at the levels you want. Pushing an amp into clipping constantly is a sure way to cook tweeters, as others have said. Making sure you have plently of clean power and headroom is a very good thing.

There are some speaker companies that do without traditional tweeter protection all together and use a light-bulb in series with the tweeter.

The idea there is that the bulb increases in resistance as more voltage passes through, and discharges the excess energy as light and heat. This trick has been used in pro-gear for some time, and I know for sure it is used in some Bose and Wharfedale designs too. Another benefit of the bulb method is that (in theory) it operates in "real time" with the signal. The signal does not already have to be into clipping before it operates. And, because it is purely resistive, it should not adversely affect the signal- at least any more than an L-pad.

 

[dr*audio]

Yes, Bose does use the lightbulbs as protection devices, probably as good a reason not to use them as any. The vibration from the sound is not kind to the filaments, I used to replace the damn bulbs all the time. And it didn't seem to save the tweeters, either. Maybe it was the crappy tweeters Bose used...

 

[Tom Blasing]

5 years ago when I first got my Klipsch KLF-20's I toasted to pair of tweet diaphrams. Yes, I was clipping the amp section of a Carver MX-150 receiver, the dbx 3BX-Series Two was set with too high a threshold and had the EQ set too high on top of that. So yea, it was bound to happen.

Then I soldered an automotive (12v DC) tail light bulb in line with the negative lead inside the speaker cabinet to the diaphram.

No problems ever since.

Much later I upgraded to better (McIntosh) gear with the autoprotect.

 

[GordonW]

I saw what is probably the most comprehensive tweeter protection ever, in an Infinity with an EMIT tweeter. Fuse, then a bulb, THEN Zener diodes paralled across the tweeter, to SHUNT OFF excess input. If you get steady-state slight overload, the bulb lights up. If you get sudden BANG in the input... the zeners go conducive, SHORT the line, and the fuse blows!

Don't think I'd want to hear what that sounds like at high volume (could be one of the reason I find some Infinity speakers to be lacking in dynamic range, with the "compression" via the zeners and the bulb), but I pretty much guarantee, it's going to SIGNIFICANTLY EXTEND the lifespan of the tweeter!!

Regards,
Gordon.

 

[junkaudio]

use a mcintosh amp with autoformers you will never have dc on your speaker

 

[GordonW]

Ain't DC that's the problem, it's clipping harmonics. The function in the Mc amps that will help, is the PowerGuard, not the autoformers. PowerGuard== limiter...

Regards,
Gordon.

 

[ellitoid]

My Mach 2's have light bulbs in them.. :thmbsp:

 

[dnewma04]

I was just going to suggest getting a limiter if you are afraid of the uncontrollable urge to keep turning the volume knob to the right. And as Gordon eluded to, clipping or square waves are NOT DC.

 

[mywifespissed]

Tube amp (no clipping, no dc to the drivers). A Mosfet amp, very hard to fry and usually used in better quality high current amps.

 

[dnewma04]

Clipping <> DC

 

[EchoWars]

Well, not only that, but where'd ya hear that tube amps don't clip?

 

[soundmotor]

Yes, Bose does use the lightbulbs as protection devices, probably as good a reason not to use them as any. The vibration from the sound is not kind to the filaments, I used to replace the damn bulbs all the time. And it didn't seem to save the tweeters, either. Maybe it was the crappy tweeters Bose used...

In my experience, bulbs have worked great with minimal downside.

(I've yet to come across anyone who can hear them in an A/B either.)

 

[dnewma04]

Bulbs are not unusual in pro-gear, so the rigors of residing in B*** gear shouldn't be too harsh for them. Unless they bought the bulbs from the same source they get their drivers from.

 

[Paul C]

I have to echo Dr Audio's comments about bass boost pushing the amp into clipping.

I also agree that most tweeter protection is pretty much useless, though the light bulb does give a soft limiting that works well. It is used in some pro gear.

Your best bet is to use an amp with plenty of power. Clipping will toast a tweeter faster than anything. You are not doing your speakers a favor by using a low power amp.