Speaker overload (tweeter) protection using bulbs (repost)

OTOH distortion does not destroy speakers, speakers are as happy to play distortion as clean signal only when you exceed the heat dissipating ability of the motor do you burn out a speaker

clipping does not damage speakers and distortion does not damage speakers, its overheating and over excursion that damages speakers distortion is one method of achieving overheating, but you can overheat with a spotlessly clean signal as well

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Although what you say is true in terms of physics (the speaker's excursion limits do not have a necessary relationship with its heat-dissipating capability), in practice, audible distortion is a warning that you should turn down the volume. William Michael Watson Dayton-Wright told me horror stories of how he could not design a speaker with sufficient power-handling capability to keep "deaf" listeners from overdriving and damaging it.

The distortion I was talking about was the sort that comes from pushing it into its excursion limits.

As in...

Same brewery but this IPA

I like to protect gear from whatever might come, so I like lamps and polyswiches. I would be almost as happy with a frequency-selective limiter that could independently account for the thermal and displacement limits of the tweeter, mid and woofer (with appropriately different time constants - an even greater challenge), but the reality is that a lamp in the tweeter circuit handles 80% of abuse, so it's cheap insurance.

But an interesting twist is that with the simple 2nd order HPFs I have been trying (with a very high Fc, eg 8 kHz, to flatten CD horn response and match sensitivities), a lamp or polyswitch in the INPUT to the crossover has the nice benefit of also seeing more MF, and so potentially account for both thermal and displacement limitations. Admittedly the time constants cannot be independent as would really be required, but it's still better than having the lamp in the crossover output circuit, and a LOT safer for the amp, which becomes UNLOADED when the protection operates, instead of shorted.

Tony

Jeez...a little knowledge is a dangerous thing.

Suggest you try driving a DC coupled amp into heavy clipping and see the results to speakers which can nominally handle its output.

and to what point is this abuse of equipment warrented? should I trow my cabinets off tall building to prove that they will be destroyed? this is the PRO LIVE SOUND newsgroup we do not drive ANY amps into heavy clipping, for any reason what-so-ever George

Really?, I'll make sure I don't do business with you.

Btw, distortion due to amplifier saturation, even though the amp is far belong the rating of the speaker can and does over heat the speaker coil and thus, can terminate the life of a speaker even rated higher than said amp.

I'll say no more.

you don't have to you already stated it was the HEAT that killed the speaker the distortion was just a means to generate the heat put a 100% distored signal from a 1 watt amp into a 600 watt woofer and you will not live long enough to see it burn out. its NOT the distortion, it's the HEAT Distortion is simply one way to obtain heat, so is a blow torch and so is a clean signal with too many watts behind it

it's not the jumping off the bridge that kills you, it's the impact with the ground do you understand?

George

No, it isn't. You are cross posting to these groups:

news:rec.audio.tech news:alt.audio.pro.live-sound news:sci.electronics.repair

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aioe.org, Goggle Groups, and Web TV users must request to be white listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in your account:

There are two kinds of people on this earth: The crazy, and the insane. The first sign of insanity is denying that you're crazy.

Err, then why are you crossposting to other groups?

However doesn't 'your' group get read by equipment hirers etc?

And to suggest no pro equipment ever gets abused by pros is pie in the sky...

So a 1 watt power amp and 600 watt speakers is your formula to prevent speaker damage under all conditions? You must have very large arms.

You would have flunked electronics 101.

Clipping and DC are not the same thing. That argument was selltled years ago- only those with minimal knowledge advance it today.

BTW have driben amps to clipping on the bench hundreds of times in the last

Your problem is you are trying to talk down to somebody who knows a lot more than you.

Go learn enough to argue then come back..

Any one have some hip boots ? my normal boots aren't tall enough!

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Ahnothetr person with minimal knowledge.

George doesn't always word things the best way, but he knows a lot.

Speakers are rated for average power, over time.

Look at the area under a square wave- it is a lot larger than the area under a sine wave. What that means is more power for a longer time. What is happening is the AMOUNT of power is being increased to a speaker for a longer TIME.

Plain and simple- that is more power. It is the amout of power over time that kills the speaker...it can only shed heat so fast, put power in faster than that it will burn up.

Simple..just use a bigger amp...and drive it to peak, you can blow the speaker quickly.

Use a smaller amp, and drive it to its full power for longer, and the speaker will blow, assuming the amp is big enough to put out that much average power. Either way- it is power that is the culprit. The amount of energy being put into the speaker...put it in faster than the speaker can sink it, you will have thermal failure.

It is not DC as people who skimmed one book and didn't understand it want to insist.

Make the amp small enough, the speaker can handle any waveform. Make the amp big enough and the speaker will fail instantly with any input at all...then there are a million scenarios in between.

I disagreee with George, I use big amps and don't blow speaker, conversely people are blowing their 100 watt speakers with "50 watt" amplifiers.

Take a look at an EV speaker rating...xxx watss with pink noise for xxx hours.

Change the signal, the speaker's rating changes. Incraes the time, the speaker's rating changes.

Square waves or severe clipping is more power for a longer time. That is all it is.

Not DC, not any big mystery, it's a measurable phenomenon.

I do agree with George that sizing amps and sopeakers reduces chance for failure. But many touring companies use big amps for horns also, larger amps tend to hold their resale better, from a business standpoint make more sense to me.

Here's a semi pro example-

Loot at the price difference between a Behringer 2500 and a 1500. Not much...but come resale time you will do a lot better with the 2500..

Business is business, I buy bigger amps. your mileage may vary.

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Jeez- another idiot to killfiter- where are you pointing out what I said was wrong?

No where- simply because you don't know enough.

Hey, even Pros get abused by other Pros...

Dave we've gooten off on the wrong foot, but what happens is Eeyore starts these damn crossposts.

He has been asked a number of times to stop.

He's a nice fellow but he keeps staring into space and mumbling "crossposting is good".

What it does is throw groups of people together who don't know each other...it ALWAYS wstarts fights .PERIOD.

I wish Graham (Eeyore) would stops as he's been asked to- but he's convinced he's right, and no amount of logic is gonna change that..

Pot, kettle.

HTH.