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<blockquote data-quote="thch" data-source="post: 5863631" data-attributes="member: 562032">clipping can be estimated with a HU that uses a discrete based volume control, eg setting 10 of 35, vs a knob you just turn.in this case, you can turn the gain down, and then measure the normal volume setting, and 3 taps downs.&nbsp; the idea is that the 3 taps down will always be the same percentage down.&nbsp; eg, 50% down (if each tap is -2dB).so as you adjust the gain, you&#039;ll be able to plot how close the ratio is.&nbsp; eg, at 10V output (on the full output case), the ratio might be 1/2.&nbsp; set the HU back to normal, and set the gains for 20V, try this test again, and you might still get around 1/2.&nbsp; repeat this.&nbsp; maybe at 30V, the ratio is still the same.&nbsp; then at 40V the ratio is a bit less.&nbsp; then at 45V the ratio is 1/1.this gives a fairly low resolution way to determine that 40V is likely too high, and 45V is definately too high.&nbsp; But the DMM generally only has a couple of digits output, and may have other issues.a similar method can be used to estimate clipping on the HU, but only if the taps are the same.&nbsp; lower taps may be -2dB while upper taps are -1dB, or maybe all taps are -2dB or -1dB.&nbsp; but there are other volume affecting controls.&nbsp; the idea is to get a fixed and precise change, and make sure that the percentage change isn&#039;t affected by other settings.again, the estimate will be affected by any limitations of the DMM, and is fairly lengthy.there are other ways to estimate clipping using a DMM and creativity.&nbsp; A twin-t filter can be used to reject the main signal, in which case only distortion gets through.&nbsp; you can actually get pretty good results this way, but it does still need a bit of tuning, as your filter tends to be imperfect.</blockquote>

[QUOTE="thch, post: 5863631, member: 562032"] clipping can be estimated with a HU that uses a discrete based volume control, eg setting 10 of 35, vs a knob you just turn. in this case, you can turn the gain down, and then measure the normal volume setting, and 3 taps downs. the idea is that the 3 taps down will always be the same percentage down. eg, 50% down (if each tap is -2dB). so as you adjust the gain, you'll be able to plot how close the ratio is. eg, at 10V output (on the full output case), the ratio might be 1/2. set the HU back to normal, and set the gains for 20V, try this test again, and you might still get around 1/2. repeat this. maybe at 30V, the ratio is still the same. then at 40V the ratio is a bit less. then at 45V the ratio is 1/1. this gives a fairly low resolution way to determine that 40V is likely too high, and 45V is definately too high. But the DMM generally only has a couple of digits output, and may have other issues. a similar method can be used to estimate clipping on the HU, but only if the taps are the same. lower taps may be -2dB while upper taps are -1dB, or maybe all taps are -2dB or -1dB. but there are other volume affecting controls. the idea is to get a fixed and precise change, and make sure that the percentage change isn't affected by other settings. again, the estimate will be affected by any limitations of the DMM, and is fairly lengthy. there are other ways to estimate clipping using a DMM and creativity. A twin-t filter can be used to reject the main signal, in which case only distortion gets through. you can actually get pretty good results this way, but it does still need a bit of tuning, as your filter tends to be imperfect. [/QUOTE]

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