clipping

[B7L|BL4Z3R 4]

ok so i have read and talk to alot of people about clipping and i still dont understand, what is it and how do you prevent it? and how can you tell if your clipping or not

[NB50 206]

http://en.wikipedia.org/wiki/Clipping_(audio)

[rumproast789 0]

Everyone says you can hear it, but I don't get how I can hear it? What does it sound like?

[Noobtastic14 0]

what clipping looks like

i can hear it in a sine wave but clipping in music is a bit harder to pick out.

-Drew

[B7L|BL4Z3R 4]

ok so how do you prevent it?

[Noobtastic14 0]

Gain Knob

the only way to know for sure or not if your clipping is an Oscope (like the one i have, shown in the vid)

you can use an online calculator to make the output voltage of your amp "match" the input voltage but that does not mean that you wont ever clip. Its also common to set your gains with a -10db overlap to allow minimal clipping. Your sine wave is much more powerful than music so if set at 0db sine wave it will sound VERY disappointing on music (but with NO clipping!)

so to compensate for switching from a sine wave to music, you need a calculated gain boost (-10db for woofs, 0db or -5db for mids and 0db for tweets)

sorry for rambling- just make sure your set up right

-Drew

[B7L|BL4Z3R 4]

so, if i just keep my amp low it shouldnt clipp to where anything will burn up?

[hiloracerboy84 0]

not necessarily..depends on hu voltage, bass bosters, eq, vol....

[B7L|BL4Z3R 4]

i guess im just never going to understand

[sick6ness 1]

i guess im just never going to understand

Just get an o-scope to set your gains. And be worry free

[bassahaulic 155]

Do you smell your woofer when bumping?

[B7L|BL4Z3R 4]

im not clipping, im not hooked up but i want to be sure when i get it that i am not and iwant to be able to tell my friends and do installs withouth there subs clipping

[Adrian_D 520]

Set your gains properly maybe ?

Also, there's a topic related to clipping posted over here by 95Honda that has some very informative links.

[hiloracerboy84 0]

Heres my stab at trying to easily sum up clipping:

your HU has a preout voltage...this is a rated voltage that it puts out of clean signal at a given volume level. granted, this voltage will be reached quicker when using different features on the deck. i.e. - using bass boosters, eq, sub level control. - w/ flat eq, and sub level all the way down, you may be able to play at vol 45/62 to reach given voltage. if the eq is set with some +db in bass, and the sub level is all the way up, you may reach that same voltage at vol 32/62. this is for the HU output voltage.

amp gains are marked w/ maybe 8v-.2v or whatever. like how people say "the gain is not a volume knob", this is where this comes in. the gain is to match your gain to the HU output to optimize output. there will be a spot...some spot (oscope will find it - right before the signal clips) that the gains are matched. this can be roughly done with a dmm and some formulas too. Setting the gain on an amp is usually done w/ a test tone as this usually presents the most stressful situation an amp will face (music is usually recorded at a lower vol), and gives you a point to set your gain at so as not to clip w/ on music (the stressful situation of the tone gives you headroom on music).

Once that matching point on the amps gain is passed (using it as a vol knob or just not caring), the amp does as it is "told" and amplifies the signal it is being fed even more. Since there is no more "clean" signal to amplify, the wave becomes distorted. How do you make a round object bigger? same way that kicker used the L7 concept - make it square-er. (picture a wave w/ peaks and troughs all nice vs. the notches/teeth on a gear). Though the waves may have the same amplitude (height), the square waves have more area under them. This non-linearity and offset of power to wave amplitude (amount of power) equals the same amount of linear output to the speaker, yet the square wave has that much more "area" or power under it. This added power per given output to the speaker creates extra heat that the speaker can't efficiently cool itself with (using whatever features it has - pole, cooling vents, channels etc.). ultimately, this leads to burnt voice coils, maybe burnt tinsels...a blown speaker. THIS is why some people blow a 1000w sub on 500w, and many safely run 3,4,5k watts to a 2k watt speaker...its all about having a clean undistorted/unclipped power source (you get into the thermal/mechanical limits here too, but these guys usually know when to turn it down, but a lot of times, with clean signal, a speaker can surpass its rated power and run fine). i guess this is why there's a lot of recommendations to get amps bigger than what speakers are rated for....so even if they do use the gain as a vol knob, theres less of a chance that it'll reach clipping at their preferred "volume" level. (running extra power is always good too imo, but thats a diff. story)

anyway, hopefully this explanation kinda clears things up a bit on clipping. i tried to make it as basic/general as possible. i know there's prob a bunch of mistakes to it, so the experts should chime in and correct me when they see some mistakes.

[KU40 173]

it sounds like a dull thud when the subs play.

[95Honda 486]

Clipping has never blown a speaker. Only too much power has. That is it, as simple as it gets.

Unless you have done an objective test with this, like I have here:

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

You probably don't understand what is really going on.....

If you aren't sure how to tell if you have too much power, either a) get less power -or- b) buy extra woofers.....

Setting your "gain properly" is a load of BS, IMO.... Using an O'scope is a complete waste of time and gives you nothing but a false sense of security.... Bottom line is, if you can't tell when you are blowing subs, and you actually care, then you need to have less power on tap or find a different hobby....

You can't blow a 1000rms speaker with a 500 watt amp (within the general realm of sanity) unless either of the manufacturers have lied about the specs...

[B7L|BL4Z3R 4]

thanks guy, so whatever i set my bassboost on my hu i should match with my amp? i think thats what you were getting too. that made me understand WAY better. i really apppretiat the help thanks ssa any more oppintiuns would be nice

so when i hook my amp up i should keep my gain low on my hu and my gain on my amp about 3/4 (amp is rockfordfosgate t30001bd

Edited March 5, 2009 by B7L BL4Z3R

[B7L|BL4Z3R 4]

so if i get this, clipping is when your input voltage is differnt then your output voltage? and that the only way to completely prevent that you have to use an oscope/?

[95Honda 486]

so if i get this, clipping is when your input voltage is differnt then your output voltage? and that the only way to completely prevent that you have to use an oscope/?

No and No.

Clipping is when the AC component of any amplifier/buffer in signal chain is trying to swing more voltage than what the DC rails supply. Basically, the top and bottom of the sine, or any signal, get flattened, or "clipped"

An O-scope never prevents clipping. The only thing that prevents clipping is not overdriving the input to any of the stages of amplifier/buffer in your signal chain.

If you have a tough time with this, a simple answer is the volume knob on your deck caauses clipping when you turn it up too high....

[kryptonitewhite 1]

Everyone says you can hear it, but I don't get how I can hear it? What does it sound like?

http://realmofexcursion.com/videos/Adire/brahma12.13.wmv

[B7L|BL4Z3R 4]

i always thought that noise was when you blew a woofer to be honest

[B7L|BL4Z3R 4]

when the signal from your deck is too large, your amp cuts down the signal to make it (fit) and since your amp cant produce that large of a signal it causes it to clip?

[kryptonitewhite 1]

Clipping has never blown a speaker. Only too much power has. That is it, as simple as it gets.

Unless you have done an objective test with this, like I have here:

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

You probably don't understand what is really going on.....

If you aren't sure how to tell if you have too much power, either a) get less power -or- b) buy extra woofers.....

Setting your "gain properly" is a load of BS, IMO.... Using an O'scope is a complete waste of time and gives you nothing but a false sense of security.... Bottom line is, if you can't tell when you are blowing subs, and you actually care, then you need to have less power on tap or find a different hobby....

You can't blow a 1000rms speaker with a 500 watt amp (within the general realm of sanity) unless either of the manufacturers have lied about the specs...

man it was good to re-read that, it's been years. Thanks honda! Boy, I'm worried all over again... I guess when I get me recone I will know....

[95Honda 486]

If an amplifier is amplifying, the output signal is always larger than the input, hence "amplification". If it does not put out more voltage it is usually a buffer to isolate and drive varying impedances. Amplifiers are rated with voltage gain, i.e. X volts in gives you Y volts out depending on the gain of the amplifer. The gain adjustment (if there is one) is what sets the ratio of input voltage to output voltage (gain). If there is no gain adjustment, it is fixed as set by the manufacturer. This amount of gain is rated in db. 25-30db is an average gain for an amplifier. Each 6 db doubles the voltage output as compared to the input. So if you have an amp with 30 db of voltage gain, 1 V on the input equals 32V on the output....

If you apply an input voltage that exceeds the threshold of what it takes to produce maximum amplifier output (voltage) then you run the amp into clipping. The input voltage to do this is all dependant on the voltage gain of the amplifier. It cann't be broken down (correctly) any simpler than this....

Again, if you apply more voltage to the amplifier input than what is required for full output, it clips.

[kryptonitewhite 1]

I'm running my amp with an LOC and my factory HU... makes things tricky... I have a DMM but i've heard it's not very effective? Minimum of a clamp meter??