is this possible: clipping detection using a dmm?

[IgnoreMe 5,000+ posts]

i thought of something and im not sure if it would work or how accurate it would be. i think my logic on this one is right, but the answer is wrong, as im sure someone would of already done it if it works...

but heres what im thinking:

an amp puts out an AC signal. when you clip the signal you are basically changing the signal to a DC signal. do you guys think it would work (and be accurate) to say hook up the dmm to read DC voltage, put in a 50hz tone blah blah blah (follow the gain tutorial) and then turn the gain up to until the dmm shows a dc voltage (clipping)?

i would think the dmm should pick up the dc voltage which would indicate clipping no?

just a thought i had while taking a dump this morning //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

Click to read more...

 

[hoss 5,000+ posts]

i think that would work, in theory.

but in reality, it would only show you when the signal is clipped 100% i believe. you can however, use the DMM to find the point of power compression, which occurs when clipping starts.

 

[IgnoreMe 5,000+ posts]

i think that would work, in theory.
but in reality, it would only show you when the signal is clipped 100% i believe. you can however, use the DMM to find the point of power compression, which occurs when clipping starts.

yea, i kinda figured someone would of taken off with this idea a long time ago if it worked.

but, hey, you got any info or links on that power compression info you posted?

 

[hoss 5,000+ posts]

i dont have any links, but im sure its out there somewhere //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

basically, just hook your DMM up to your amps outputs, play a test tone at your maximum volume level, and slowly turn your gains up on the amp while keeping an eye on the DMM. you should see your AC voltage rising with the gain, when the voltage stops increasing (or the voltage starts increasing less as you turn the gain up) then you are entering into compression, AKA clipping //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[squeak9798 5,000+ posts]

Keep in mind that a clipped signal is NOT DC. The clipped signal, or a true square wave, is the a fundamental waveform (AC) combined with all of the harmonics of that fundamental.

So I'm not honestly sure that the DMM would register it as "DC" voltage as that is not what it is.

 

[IgnoreMe 5,000+ posts]

i dont have any links, but im sure its out there somewhere //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
basically, just hook your DMM up to your amps outputs, play a test tone at your maximum volume level, and slowly turn your gains up on the amp while keeping an eye on the DMM. you should see your AC voltage rising with the gain, when the voltage stops increasing (or the voltage starts increasing less as you turn the gain up) then you are entering into compression, AKA clipping //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

i searched google, but i got links to all kinds of computer pages and stuff lol.

but, that reminds me. i was messing setting my gain on my kx2500.1 and i set using volume 70 instead of volume 55 like normally, but i forgot to drop the gain all the way down, and my voltage jumped up to like 130V.

for 3000w of output (birthsheet says 2960@ 2ohms) i would be at ~75v. so im assuming i still have plenty of headroom before clipping is induced.

 

[IgnoreMe 5,000+ posts]

Keep in mind that a clipped signal is NOT DC. The clipped signal, or a true square wave, is the a fundamental waveform (AC) combined with all of the harmonics of that fundamental.
So I'm not honestly sure that the DMM would register it as "DC" voltage as that is not what it is.

ahhh, the misinformation of ca.com rears its head.

ive read the clipped ac = dc here unfortunatly //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

edit: kinda thinking about it more...how would an ac signal that alternates polarity ever equal to a dc signal which is always the same polarity...lol

 

[Safe-N-Sound215 10+ year member]

I think jbl's site has something about power compression on it. Let me see if I can find it.

 

[hoss 5,000+ posts]

squeak, i wish that just once you would post some useful information //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[IgnoreMe 5,000+ posts]

squeak, i wish that just once you would post some useful information //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

tis true. hes never been very helpful

 

[squeak9798 5,000+ posts]

I don't think I've ever heard the term "power compression" used in reference to an amplifier before.

But the essence of what Hoss is saying is right.....eventually you'll reach the rail voltage of your amplifier and the voltage will cease to increase any further.

I certainly would not use this as a method by which to set gains or determine the level of acceptable distortion, however.

 

[squeak9798 5,000+ posts]

squeak, i wish that just once you would post some useful information //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

//content.invisioncic.com/y282845/emoticons/moon.gif.9d317aec3339ffe7fde0638df52c628a.gif

 

[xtremebassjunky 10+ year member]

lol.

 

[DBfan187 5,000+ posts]

i thought of something and im not sure if it would work or how accurate it would be. i think my logic on this one is right, but the answer is wrong, as im sure someone would of already done it if it works...
but heres what im thinking:

an amp puts out an AC signal. when you clip the signal you are basically changing the signal to a DC signal. do you guys think it would work (and be accurate) to say hook up the dmm to read DC voltage, put in a 50hz tone blah blah blah (follow the gain tutorial) and then turn the gain up to until the dmm shows a dc voltage (clipping)?

i would think the dmm should pick up the dc voltage which would indicate clipping no?

just a thought i had while taking a dump this morning //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

Clipping IS NOT DC, it's still oscillating, so it's AC. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[IgnoreMe 5,000+ posts]

I don't think I've ever heard the term "power compression" used in reference to an amplifier before.
But the essence of what Hoss is saying is right.....eventually you'll reach the rail voltage of your amplifier and the voltage will cease to increase any further.

I certainly would not use this as a method by which to set gains or determine the level of acceptable distortion, however.

well currently i just use the standard dmm, test tone procedure as i dont have access to an oscilloscope anymore.

i was just trying see if there was maybe a different, and better, way of going about it.