Why not? If you understand the power limitations of your cab, there is no harm in sending it a clipped signal.
Driving your head to its death is another matter altogether.
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Can't blow a speaker by under powering it.......
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Why not? If you understand the power limitations of your cab, there is no harm in sending it a clipped signal.
Driving your head to its death is another matter altogether.
I plan to go clip the dickens out of my guitar amp tonight. Last Sunday I had the pleasure of playing guitar through a couple of Victorias simultaneously (does that sound dirty?) (let's call it $4500 worth of amps), and clipped them without remorse. Or negative consequence.
Don't clip your amp if you have a tweeter and the tweeter's power handling is not sufficient for the excess energy.
Don't clip your amp if you have a tweeter and the tweeter's power handling is not sufficient for the excess energy.
I'm familiar with inertia. If the DC component of the waveform is long enough, time wise, and the frequency low enough the cone will stop. The more responsive the speaker and the better control the amp has over the speaker (damping factor) the longer the speaker will be stopped.
It's best to not drive the power amp into clipping, but for other reasons, mainly stressing the power transformer or output transformer if there is one.
As long as a speaker system can handle the total power and thermal dissipation of a square wave, you're in like Flynn, golden, high five, it sounds great, whatever. If you are in a borderline situation where the speaker system will handle the total power but not the extra thermal load of a square wave you will see toasty voice coils or rub marks due to thermal expansion. How much time will it take? Depends.
mech
Mr. Foxen
Commercial User
If both those traces share a common 0v point, one of them has DC, because it isn't in the middle. But if they are two separate traces, and 0v is in the middle of each, the flat bits are both sides of the line, alternate sides of the line, because they are alternating.
Basically the way you know a square wave isn't DC, is because of the word 'wave' in the name.
But totally drive your amp into clipping, and use a valve amp, because that sounds awesome.
Edit: And this thing about the speaker being stopped, has already been made fun of with the amp being turned off thing. Same deal, not moving.
Basically the way you know a square wave isn't DC, is because of the word 'wave' in the name.
But totally drive your amp into clipping, and use a valve amp, because that sounds awesome.
Edit: And this thing about the speaker being stopped, has already been made fun of with the amp being turned off thing. Same deal, not moving.
mech said:
A square wave is not DC. DC is the flow of current continuously in one direction. The fact that it alternates makes it AC. A sine wave has a large DC component by that definition as it spends all but the zero crossing at only positive or negative. The fact that it is flat does not make it DC, most power supplies don't put out a flat level; there are varying degrees of ripple.
To test this, run a square wave through your amp and use a multimeter set to read DC voltage to see what it's putting out. It should be zero, or nearly zero if there is offset. If there is offset it will appear like a square wave but the zero point will be at whatever the offset is rather than zero. AC amounts to zero volts DC.
The only thing a square wave has in common with DC is that the power output will be the same for the same voltage.
Yep.
Absolutely.
Now, what happens when you don't give it a higher input level?
Something along the lines of X-Y happens to that output power, doesn't it?
All true.
So play your guitar into that Twin Reverb. Now turn the master volume way down, and play the same thing again. The input level didn't change, or at least not dramatically. So... what happened, that made it so much quieter?
Stopped in the neutral position with zero power applied is the not the same as being stopped at X amount of excursion while dissipating the DC power applied. You may laugh all you wish but the comparison is carrots to a L6 Corvette.
mech
Mech, you're spinning your wheels. You're not going to convince them of anything, no matter how much you know or what you've seen and experienced yourself. You're trying to help the guy not to get shot, but instead people want to argue that it's not the bullet that kills you, it's the hole. I'm an EE myself, I've been down this road, and I'm telling you you're wasting your time. Let it go.
Square wave business aside, I find separating "extra thermal load" from "power" highly interesting.
How many joules of "thermal load", for how long?
The guitar has a limited amount of output. Once that max is reached, the SPL from the speaker is controlled by the overall gain of the amp system as set by preamp output and the sensitivity of the power amp.
mech
The lowest frequency component in any AC signal is the fundamental. So the lowest frequency component in say a 1KHz square wave is .... you guessed it, 1KHz. All the other stuff that makes it a square wave is made up of harmonics i.e. higher frequencies than 1KHz. There's no room for DC (0Hz) in there.
Or the energy delivered by the impact.
Or on the other end of the spectrum... the actions of some entity that caused the firing pin to strike the cartridge. (Or the spark to hit the powder, if you're into antiques.)
It's really simple... if a speaker is damaged, it took more power than it was designed to take, in the manner in which said power was delivered. Even stabbing a knife into it could be classified that way.
So does damaging pretty much *anything else*, for that matter.
Yeah. Mmm-hmm.
And once that is all figured in, with that guitar cranking away at full output... what will a measuring device tell you happens at those output terminals when you turn down one or more of those gain controls?
I agree...it's best to ignore the words of thousands, maybe even millions, of players who have driven their amps into clipping with no ill effects on the speakers.
Or it's a perfectly functional Crown DC.
The story here is direct current kills voice coils. Don't hook your speakers up to batteries or run low freq square wave signals into laboratory amplifiers that work down to 0Hz.
Extra thermal load is power that is not causing useful work and being dissipated as heat that is outside the design parameters of the system. Any system that creates or uses power will have thermal limits designed in.
How many joules? More than the system was designed for. How long? Depends on the amount of overload.
I'm sure there are people on here who have computer programs that may be able to give you specifics for any amp/speaker combination.
Yep, you're right. I'm outta here.
mech
bongomania
Commercial User
Yes, I recall you saying something about decades ago working at a power plant or some other commercial facility that at no point ever involved speakers or audio electronics...
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