difference from a sub clipping and bottoming

[only126db 10+ year member]

Sorry but thats not 100% true. If a lab were to analyze the "coke" you had in your car and it did not match the illegal chemical substance that makes up cocaine it would be dismissed in court. In order to be charged with possession of cocaine the powder that is collected at the scene must have the proper chemical make up as specified by the law.
This has caused the rise of designer/synthetic drugs. What people have started doing is altering the chemical make up of illegal drugs to make them be considered different substances, however maintaining the desired side effects. They have also been able to make drugs exponentially more potent and effective.

EW CHEMISTRY //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

Possesion of a controlled substance.

They do not use labs to analyse narcotics, thats only on tv, they use field test kits.

If it turns a certain color it's classified as a certain drug, it only has to have certain elements to be considered such.

Which then again leads to the duck theory.

But whatever, tired of arguing this, the outcome is all going to be the same whether it be true DC or a DC clone sent to your speakers, it's bad for the amplifier and speaker to continuously run in a full clipped scenario if there is any argument to the contrary then enjoy the magic white smoke from your equipment.

 

[Mass Car Audio 10+ year member]

Possesion of a controlled substance.
They do not use labs to analyse narcotics, thats only on tv, they use field test kits.

If it turns a certain color it's classified as a certain drug, it only has to have certain elements to be considered such.

Which then again leads to the duck theory.

But whatever, tired of arguing this, the outcome is all going to be the same whether it be true DC or a DC clone sent to your speakers, it's bad for the amplifier and speaker to continuously run in a full clipped scenario if there is any argument to the contrary then enjoy the magic white smoke from your equipment.

IT IS NOT DC CURRENT !!!!!!!!!!!!!!!!!!!!!

It is not hard on a amp to produce a clipped waveform, they are designed to make a square wave to process the signal but when you drive your amp to it's limit it will over heat or get low voltage causing the amp to blow.

 

[bose301s 5,000+ posts]

Possesion of a controlled substance.
They do not use labs to analyse narcotics, thats only on tv, they use field test kits.

If it turns a certain color it's classified as a certain drug, it only has to have certain elements to be considered such.

Which then again leads to the duck theory.

But whatever, tired of arguing this, the outcome is all going to be the same whether it be true DC or a DC clone sent to your speakers, it's bad for the amplifier and speaker to continuously run in a full clipped scenario if there is any argument to the contrary then enjoy the magic white smoke from your equipment.

Wow, you haven't been correct on a single thing you have said in this thread. Considering I know people who have been stopped i real life for narcotics I can assure you they do test the substance, they legally have to to charge you with anything. I'm glad you decided to shut up though because your moronic drivel will only make people on this forum dumber.

 

[only126db 10+ year member]

Wow, you haven't been correct on a single thing you have said in this thread. Considering I know people who have been stopped i real life for narcotics I can assure you they do test the substance, they legally have to to charge you with anything. I'm glad you decided to shut up though because your moronic drivel will only make people on this forum dumber.

I didnt decide to shut up.

As for your friends being stopped 'in real life' for narcotics that makes you a pro, hearing second hand info from people who have probably blown up their situation to look cool to you.

I know just a little bit about the whole process of dealing with the narcotics issue and the police.

You just go ahead and think what you want on that situation.

Oh and I never said they didnt test the narc's, I stated 'field' testing, not a lab like on CSI.

 

[only126db 10+ year member]

IT IS NOT DC CURRENT !!!!!!!!!!!!!!!!!!!!!
It is not hard on a amp to produce a clipped waveform, they are designed to make a square wave to process the signal but when you drive your amp to it's limit it will over heat or get low voltage causing the amp to blow.

Ok well I guess you are right and I am wrong (read below)......

Here are some emails I sent and recieved:

To Zapco from me:

Is it hard on an amp when it is producing a clipped waveform?

From Zapco to me:

Yes

To McIntosh from me:

Is it hard on an amplifier when it is producing a

clipped waveform?

From McIntosh to me:

It is not too great for the amp, it also produces about 10 times as much

energy in the high frequencies and will blow tweeters,

The Power guard circuit will keep McIntosh amps from clipping with up to

16dB of over drive, so even with the power guard light on full, you

would still have to turn the preamp up a bunch more before it will clip.

 

[Mass Car Audio 10+ year member]

Ok well I guess you are right and I am wrong (read below)...... Here are some emails I sent and recieved:

To Zapco from me:

Is it hard on an amp when it is producing a clipped waveform?

From Zapco to me:

Yes

To McIntosh from me:

Is it hard on an amplifier when it is producing a

clipped waveform?

From McIntosh to me:

It is not too great for the amp, it also produces about 10 times as much

energy in the high frequencies and will blow tweeters,

The Power guard circuit will keep McIntosh amps from clipping with up to

16dB of over drive, so even with the power guard light on full, you

would still have to turn the preamp up a bunch more before it will clip.

The only reason a clipped waveform is going to kill a amplifier is if you have the gain not set right and your bass boast on causing it to over heat from high rail voltage or low DC input voltage. Hes stating it is hard on the speakers with high output voltage with high frequency's. I did not read anywhere in your post him saying that a clipped waveform will hurt the amplifier. All he is saying is they have a protecting circuit that will not let the amplifier produce a clipped waveform above 16db but it will still produce a clipped waveform up to 16db.

 

[bose301s 5,000+ posts]

I didnt decide to shut up.
As for your friends being stopped 'in real life' for narcotics that makes you a pro, hearing second hand info from people who have probably blown up their situation to look cool to you.

I know just a little bit about the whole process of dealing with the narcotics issue and the police.

You just go ahead and think what you want on that situation.

Oh and I never said they didnt test the narc's, I stated 'field' testing, not a lab like on CSI.

Actually, it is not second hand info. I have held the report from the Michigan State Police laboratory in my hand. Another swing and a miss.

 

[DBfan187 5,000+ posts]

Clipping IS NOT DC in any way..................

 

[DBfan187 5,000+ posts]

http://www.audiogroupforum.com/csforum/showthread.php?t=4332&highlight=clipping

read it!

The only thing that thermally damages speakers is power... more specifically: average power over time.
I'll explain...

If you take a given amplifier, let's say 100 watts and operate it just below clipping with music material, the "Crest Factor" of the amplifier's output is equivalent to the "Crest Factor" of the program material.

"Crest Factor" is the difference between the average level of the signal and its peak level. For example, a pure sine wave has a "crest factor" of 3dB, meaning that it's peak level is 3dB higher than its average level. We all know that 3dB represents a power factor of 2, so another way to look at it is that the peak power of the signal is twice that of its average level. So, if we play a sine wave on our 100 watt amplifier, just below its clipping level, the average power (over time) the speaker is needing to dissipate is 50 watts.

A true square wave, by comparison, has a crest factor of 0db, so it has equal average and peak power. Our 100 watt amplifier, playing a square wave, unclipped, into our speaker requires that the speaker dissipates 100 watts of power (twice the heat as a sine wave).

Music has a significantly higher crest factor than sine waves or square waves. A highly dynamic recording (Sheffield Lab, Chesky, etc.) typically has a crest factor of 20dB or more, meaning that its average power is 100 times lower than its peak power. So, if we play our 100 watt amplifier just below clipping with the typical audiophile recording our speaker is only needing to dissipate 1 watt of average power over time.

Modern commercial recordings typically exhibit crest factors of around 10dB, meaning that the average power is 10 times lower than the peak power. So, our 100 watt amp just below clipping would deliver an average power over time of 10 watts that the speaker has to dissipate.

Okay, so what happens when we clip the amplifier (which we all do at times). When the amplifier enters into clipping, the peak power no longer increases, but here's the KEY... THE AVERAGE POWER CONTINUES TO INCREASE. We can often tolerate a fair amount of clipping... as much as 10 dB or more above clipping with a reasonably dynamic recording... a bit less with a compressed commercial recording.

So, if we turn the volume up 10dB higher than the clipping level with our Sheffield Lab recording, we have now reduced the crest factor of the signal reaching the speakers by 10dB... so instead of needing to dissipate 1 watt average, we are asking the speaker to dissipate 10 watts average, and we're probably ok.

If we turn up the volume 6dB past clipping on a compressed commercial recording (or bass music recording), we have taken the crest factor of the signal from a starting point of 10dB to only 4dB, asking the speaker to dissipate an average power of 40 watts instead of 10 watts... that's FOUR TIMES the average power, which generates four times the heat.

SO, in most cases, the reason clipping can damage a speaker really has nothing to do with anything other than an increase in average power over time. It's really not the shape of the wave or distortion... it's simply more power over time.

When someone plays Bass Mekanik clean (unclipped) on a 1000 watt amplifier the average power is 100 watts (10dB crest factor). You can also make 100 watts average with Bass Mekanik by heavily clipping a 200 watt amplifier.

If someone is blowing a woofer with 200 watts of power due to a lack of restraint with the volume control... they will blow it even faster with a 1000 watt amplifier because they will probably turn it up even more and now they have more power to play with... this is the recipe for aroma of voice coil.

When woofers are rated for power, an unclipped signal is assumed. We use test signal with a crest factor of 6dB for power testing and can run a speaker at its rated power for hours and hours on end without thermal or mechanical failure. For example, a W1v2 can dissipate 150 watts average power for eight hours or more with signal peaks of 600 watts. So, we rate the speaker for 150W continuous power. This way, when a customer needs to choose an amp for it, they will hopefully choose one that can make about 150 W clean power... Even if they clip the bejeezus out of that amplifier, it is unlikely that the speaker will fail thermally. This is a conservative method, but it needs to account for the high cabin temperatures in a car (think Arizona in the summer) which significantly impacts heat dissipation in the speaker. A top plate that starts at 150 degrees F is not as effective at removing heat as one that starts at 72 degrees F in the lab... and this affects the ramp up of heat in the coil.

DISCLAIMER: The frequency components of clipping can affect tweeters due to their low inductance and lack of low-pass filtering. Clipping essentially raises the average power of high frequencies to a point that can damage tweeters... Woofers and midranges couldn't care less about these high frequency components because their filtering and/or inherent inductance knocks that stuff out of the picture.

Best regards,

Manville Smith

JL Audio, Inc.

 

[only126db 10+ year member]

Actually, it is not second hand info. I have held the report from the Michigan State Police laboratory in my hand. Another swing and a miss.

Well here in California they do it a little different, a field test is all that is required here, they consider the field test as reliable as a labratory result, bypassing the expense of the lab.

I've seen this first hand myself.

 

[audioatg 10+ year member]

Possesion of a controlled substance.
They do not use labs to analyse narcotics, thats only on tv, they use field test kits.

If it turns a certain color it's classified as a certain drug, it only has to have certain elements to be considered such.

Which then again leads to the duck theory.

But whatever, tired of arguing this, the outcome is all going to be the same whether it be true DC or a DC clone sent to your speakers, it's bad for the amplifier and speaker to continuously run in a full clipped scenario if there is any argument to the contrary then enjoy the magic white smoke from your equipment.

I know here in NJ, DE mabye PA not sure about maryland. But they do a Field test first then send it off to the lab for better checking. Field tests have been proven wrong many tims. Even seen a show on MTV called busted when they had a field test proven wrong when it was sent into the lab for better testing. Not sure what state they were in though.

 

[Mass Car Audio 10+ year member]

The only reason a clipped waveform is going to kill a amplifier is if you have the gain not set right and your bass boast on causing it to over heat from high rail voltage or low DC input voltage. Hes stating it is hard on the speakers with high output voltage with high frequency's. I did not read anywhere in your post him saying that a clipped waveform will hurt the amplifier. All he is saying is they have a protecting circuit that will not let the amplifier produce a clipped waveform above 16db but it will still produce a clipped waveform up to 16db.

Also the only reason they have that protection circuit from going over 16db of a clipped signal is because it will help from killing the speakers it is driving.

 

[subzero 5,000+ posts]

X2. A amplifier that is working correctly will not put dc current to the voice coils.

Because you now have added the sine wave...AKA as music, therefore direct curent is changed to an alternating curent. it now has a signal.

I think my subs are clipping . Shitty PA amp. I need moar POWER!!!!!.

 

[tinmanchris217 10+ year member]

Everyone is pointing out some very good things and I feel this is a rare occasion where, even though people are wording things a bit differently, most are in agreement.

This is a healthy thread guys, nice job.

Bwahaha... WAS a healthy thread. *flush*

The speaker's coil creates force based on the chang in current passing though it. In a healthy setup, the V_AC gives you a quantitative estimate of how strong that force is.

When the cone stops moving momentarily, the force on the coil is already pulling the cone back, as is the spider's mechanical force. DC isn't causing this.

DC on a coil will make it push out and stay out. Similar phenomenon, but not the same.

During a hard clip, or a square wave, the coil under goes a push-hold-pull-hold cycle... which can cause heat to build up and possibly leakage/ripple. It can also damage soft parts, because the push and pull happen faster than during normal sine wave operation.

That is the end of the similarities though, because it still cycles at a high rate (30-100 Hz). If it's extremely underpowered, you'd have to clip the living snot out of the amp to cause serious damage, from the above hard clip symptoms.

 

[jordan572 10+ year member]

well it sounded like my sub was bottoming out but i find it very hard to believe because i dont think my amp has enough power. It has happened a couple times about 2-4 months ago. if the sub still plays clean no matter what volume [except when it is bottoming or clipping or whatever] i take it nothing was wreaked.