CyrusZ Posted September 23, 2014 Share Posted September 23, 2014 Hello, I have been searching for some information on how an amplifier "clips" My question is for amps how do they "clip" I think someone once explained it in a very technical way that as wattage increases the resistance decreases to the point that the amp sees a "short" and the clip light indicates the short because something about that is the maximum extension of the cone or heat or something. I also thought that wattage has more to do with dissipating heat rather than matching gain. I have a speaker I have designed and built but I am getting some early clipping and distortion from my amp, used with other cabs no issues run at 0 and we are all happy. I believe my problem is either I am running too much/little resistance (either the amp can not handle a 4ohm load or the drivers are lower ohm's than labeled) or would the wattage really be an issue, (I may have to large or small wattage) I am having trouble with explaining the issue but thank you for any advice or ways to search for more info. Link to comment Share on other sites More sharing options...
dbuckley Posted September 24, 2014 Share Posted September 24, 2014 Simply, an amplifier is clipping when it runs out of voltage. The amplifier would like to output more voltage, but it's hit the rail. Hence it's also called flat-topping. Amplifier distortion other than clipping is a bit complex, see Distortion In Power Amplifiers on Douglas Self's website. Link to comment Share on other sites More sharing options...
Jivemaster Posted September 24, 2014 Share Posted September 24, 2014 An amplifier clips when the amplified input should be bigger than the output will allow. Then attempts at high levels get truncated (or clipped ) The change of waveform introduces distortion which may kill the speaker or the amp or both. "Clip lights" rarely light at the incidence of clipping -some light 10dB before clipping, some well into clipping. Link to comment Share on other sites More sharing options...
MarkPAman Posted September 24, 2014 Share Posted September 24, 2014 I have a speaker I have designed and built but I am getting some early clipping and distortion from my amp, used with other cabs no issues run at 0 and we are all happy. I believe my problem is either I am running too much/little resistance (either the amp can not handle a 4ohm load or the drivers are lower ohm's than labeled) or would the wattage really be an issue, (I may have to large or small wattage) I am having trouble with explaining the issue but thank you for any advice or ways to search for more info. If "used with other cabs no issues run at 0 and we are all happy", but it clips at low volume with your own design of speaker, then I think your speaker must have an impedance lower than the amp's designed for. Can you tell us a bit more about your speaker design - what drivers you have used and how they're connected up? Also, what amp is it? Link to comment Share on other sites More sharing options...
Shez Posted September 24, 2014 Share Posted September 24, 2014 This page gives a reasonable explanation of amplifier clipping. You can probably ignore the maths later on but the diagrams speak the proverbial 1000 words. Link to comment Share on other sites More sharing options...
jamesperrett Posted September 25, 2014 Share Posted September 25, 2014 One other thought - are you using a passive crossover in your speaker? Is it connected properly? Link to comment Share on other sites More sharing options...
dbuckley Posted September 25, 2014 Share Posted September 25, 2014 ...but I am getting some early clipping and distortion from my amp, used with other cabs no issues Most obvious possibility: speaker impedance is higher (or, less likely, lower) than you think. Or, maybe higher than is written on the driver; it happens. Next: is there more than one driver involved? If so, do they have the same polarity? Thirdly: strange load reactance; any weird cables involved? Crossovers already been mentioned. Link to comment Share on other sites More sharing options...
audiomik Posted September 26, 2014 Share Posted September 26, 2014 ...but I am getting some early clipping and distortion from my amp, used with other cabs no issues Most obvious possibility: speaker impedance is higher (or, less likely, lower) than you think. Or, maybe higher than is written on the driver; it happens. Next: is there more than one driver involved? If so, do they have the same polarity? Thirdly: strange load reactance; any weird cables involved? Crossovers already been mentioned.You need most likely to understand Load Lines used for the design of Amplifiers and how Protection Circuitry functions to restrict Amplifier output to within this. Reactive Components within the Load to an Amplifier can cause triggering of the Protection where the phase angle of the Voltage and Current being delivered to the Amplifier Load exceeds the design values. A link to a webpage about Load Lines for Amplifier Output stages here and one on protection here A single one or a combination of the things above in dbuckley's post can be a cause of your problem. For an actual test example of this problem, have a look at the performance of two different Amplifiers of the same power output into the same reactive load: here The Amplifier test results are about half way down the page.As a followup some measured results of 'Speakers and their Power Factors (phase relationship between Voltage and Current): here Unfortunately this isn't a new problem by any means! Hope this assists, tis quite a complex subject to explain in simple terms!Information on your Amplifier and the 'Speakers/crossover you are using will certainly assist in tracking down your problem - which could also be a fault which has developed itself within your Amplifier as well Mik Link to comment Share on other sites More sharing options...
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