How to tell amp clip point

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   I havr a question how do you tell an amp's clip point? I know how to tell the true clip point of the rest of my equipment by running a 400hz sinewave though the dj mixer and then using a piezo  connected to the output of the mixer and then DSP. But I don't know how to do that with the amps because obviously the amp would blow the piezo to pieces. Would I use a oscilloscope and then touch the speaker terminals on the amp with the probes?

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Fred_dibna Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 24 September 2018 Status: Offline Points: 213	Post Options Post Reply Quote Fred_dibna Report Post Thanks(0) Quote Reply Topic: How to tell amp clip point Posted: 25 December 2019 at 6:25pm
	I havr a question how do you tell an amp's clip point? I know how to tell the true clip point of the rest of my equipment by running a 400hz sinewave though the dj mixer and then using a piezo connected to the output of the mixer and then DSP. But I don't know how to do that with the amps because obviously the amp would blow the piezo to pieces. Would I use a oscilloscope and then touch the speaker terminals on the amp with the probes?

Conanski Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 January 2006 Location: Ottawa, Canada Status: Offline Points: 2543	Post Options Post Reply Quote Conanski Report Post Thanks(0) Quote Reply Posted: 25 December 2019 at 7:40pm
	Ah.. The little red clipping led will light up? I hope you are not planning to gain stage everything so it all hits clipping at the same time. This is a terrible idea, the only piece of equipment that should ever go anywhere near the point of signal clipping is the power amp.

Fred_dibna Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 24 September 2018 Status: Offline Points: 213	Post Options Post Reply Quote Fred_dibna Report Post Thanks(0) Quote Reply Posted: 25 December 2019 at 8:39pm
	I'm just curious because some people say that the red light flickering is telling you you're getting close to clipping but being on a lot is clipping. I was actually just curious to be honest.

monkeypuzzle Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 25 January 2005 Status: Offline Points: 924	Post Options Post Reply Quote monkeypuzzle Report Post Thanks(0) Quote Reply Posted: 25 December 2019 at 8:43pm
	Stick a silly scope one it.
	blah blah blah blah blah......

Fred_dibna Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 24 September 2018 Status: Offline Points: 213	Post Options Post Reply Quote Fred_dibna Report Post Thanks(0) Quote Reply Posted: 25 December 2019 at 8:54pm
	It's not for gain staging it's more to see how much headroom the RMX4050HD amps I use have. It's just curiosity, I never clip my system and in all the years i've been doing dance music parties since 2001 i've never blown a driver. Edited by Fred_dibna - 25 December 2019 at 8:56pm

ceharden Members Profile Send Private Message Find Members Posts Add to Buddy List The 10,000 Points Club Joined: 05 June 2005 Location: Southampton Status: Offline Points: 11776	Post Options Post Reply Quote ceharden Report Post Thanks(0) Quote Reply Posted: 25 December 2019 at 10:57pm
	Unfortunately one of the problems you'll have here is that each amplifier manufacturer uses a different circuit to drive the clip light on their amplifiers and some are more accurate than others. The best ones are those that detect an increase in distortion on the output. Crown Macrotechs had this a long time ago, however they decided not to have a dedicated 'Clip' light. The C-Audio Pulse amplifiers also have a very accurate clip detection method. Other amplifiers use circuits which measure how close the output signal is to the supply rail but although this can work fine, some designs, especially cheaper amps have a very poor implementation of this which doesn't take into account variations of the supply rails or even differences due to load impedance. The best method as suggested above is to use a signal generator, dummy load and an oscilloscope to find out how the clip light is related to the actual clip point and also how well the limiting circuits (if available) work. The effectiveness of clip limiters also varies massively between amp designs. In the case of QSC then the good news is the clip light is fairly accurate and also the clip limiters are reasonably useful to. So if you're running the RMX4050 then is is true that an occasional flash of the clip light means that you're just running out of headroom. I actually set my system processor limiters a dB or so above the point where the amps either clip or limit so that I can use the full headroom available but any actual clipping of the waveform is kept to a minimum.

Fred_dibna Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 24 September 2018 Status: Offline Points: 213	Post Options Post Reply Quote Fred_dibna Report Post Thanks(0) Quote Reply Posted: 26 December 2019 at 9:40am
	Thanks for that great reply mate. :)