what is amp clipping?

[alan443 0]

im a noob,and i keep hearing about amps "clipping" what does that mean?

[jlw*22 0]

This is a good question and one thats probably best described as a reference to the difference between AC and DC current. In AC you have a signal that oscillates from positive to zero then to negative then back to zero in what would appear as triangular waves. These waves should always end in points and quickly return to zero. Now when the amplifier clips it produces a wave shaped with flat tops to those waves. This would emulate a DC current as the charge will stay either positive or negative too long to have these points as AC does. When this happens, your speaker is being either pushed or pulled longer than the input signal is wanting. It actually wants to move your speaker further, instead it is being held out or in at that same position roughly. The reason this is happening is because you have reached the maximum voltage of the amplifiers capabilities and it essentially chops the peaks of the waves. This is bad as a speaker is not designed to use a DC current and can suffer from excess heat and/or mechanical damage from over excursion. If anyone has an O-scope, maybe they would be kind to show you both proper and improper waves to better show this relationship. Hope this helps you understand the way your amp can be abused.

Also know that even though an amp is rated at a certain wattage doesn't mean it will be clipping when you turn it up a little past that rating. The ratings are based most generally on certain noise levels and or Total Harmonic Distortion. Some amps have lightening strike output ratings though. Some amps have enormous head room if you are willing to run at higher distortion levels. This is of course never recommended except for when you are doing a DB drag competition as you risk damaging the voice coil for the same reason. It is better, if you are uncertain of your amp, to keep its gain set to a known voltage for rated power or to buy an amp that is capable of more power than your application needs thus preventing both distortion and for sure clipping. Best of luck with your audio endeavors.

[topgun 262]

Moved to amplifier section, no reason for this to be in Fi.

[NDMstang65 403]

Clipping is when you reach to voltage limits of an amplification stage. Thats it.

It isn't DC, it doesn't blow speakers, it doesn't make a woofer hold still.....

If you want to understand it more, read this article-

http://www.forceaudio.com/showthread.php?t=15

Love ya to death Mike but I will have to disagree...

I've put accelerometers on cones of woofers/drivers in the lab and mapped them out..they actually do stop for a few milliseconds and it is at the bottom of the wave form. I'm working on a compilation of information that we've found, i'll post it all up much later..but according to the accels at soft/full clip they do indeed stop at X and Y, and heat does build up at that time period...

[jlw*22 0]

I learned that in Industrial Electric Class so its not some noob statement. I have seen it on O-scopes and it does emulate DC. That is fact and cannot be disproved my man. Check an O-scope on that yourself and it will show it like a dc line. No its not a solid line but the coil will react to those waves like it is for the amount of the clipped signal. If you want to see the real bad stuff take an amp set the gain to max and through a line driver that will smash its peak voltage and it will have longer flat lines. Then to show how the woofers reacts. stick a big ole battery on it and hold the leads to it for awhile and you will see the cone go one direction and stay there. Same type of signal when it is clipped. If I had a scope I would do a youtube vid for ya'll.

In short stay away from clipping. It sounds like poo and may (if you are clipping hard) damage the coil.

Edited May 16, 2009 by jw 2 + 2

[jlw*22 0]

Read this ( http://sound.westhost.com/clipping.htm ) ,it goes into detail on both clipping and distortion and how they both send DC type signal to a driver.

[jlw*22 0]

Unless the driver has a Q of around .01 and it is below a few Hz, they can't reproduce a squarewave without ringing and are never really at rest... I guess it is interpretation of what rest is beyond this point...

jw 2 + 2, did you actually read the results of clipping test?

Did you?

[jlw*22 0]

That explains why you would think it was right. Read the one I posted a link to. The fact that you do not understand what a DC wave would look like on an o-scope shows you have no knowledge of it. The DC signal is anything horizontal on the screen. That means clipping (where the peaks are cut) is DC. Read an O-scope manual.

[jlw*22 0]

[jlw*22 0]

That doesn't change the fact that you are wrong. If you were right then why are so many manufacturer's and installation companies warning of the damage a speaker getting clipped power will receive. Im not alone in this as I guess you are unwilling to read the website I have posted. I have built amps before in classes. Not a big deal. Having the tools to test it and re-design is. I'm not poking so much at you, but I think you are not understanding the way a clip signal portrays a DC signal. I learned this stuff from a Engineer whom just happens to build radio stations on the side. He has 3 degrees from electrical studies. If he's wrong then so is 99% of the people that they graduate.

[95Honda 486]

Not worth a second more of my time...

Have fun, I'm out...

[jlw*22 0]

Not worth a second more of my time...

Have fun, I'm out...

Funny that your buddy the moderator is disagreeing with you as well.

[johnecon2001 82]

We're done here. Don't disrespect the staff of this forum even if you disagree with them. EVER.

[///M5 2,833]

Clipping is when you reach to voltage limits of an amplification stage. Thats it.

It isn't DC, it doesn't blow speakers, it doesn't make a woofer hold still.....

If you want to understand it more, read this article-

http://www.forceaudio.com/showthread.php?t=15

Love ya to death Mike but I will have to disagree...

I've put accelerometers on cones of woofers/drivers in the lab and mapped them out..they actually do stop for a few milliseconds and it is at the bottom of the wave form. I'm working on a compilation of information that we've found, i'll post it all up much later..but according to the accels at soft/full clip they do indeed stop at X and Y, and heat does build up at that time period...

Accels are not a valid way to do that test, mass loading changes the damping and the whole system response. On top of that you are measuring acceleration and not velocity and with zero acceleration you can still have velocity. Time to redo your tests.

Edit: didn't realized this was closed, either way my statement is valid and considering the other was left the response will stay.