One Day Wall... *pics inside*

[audioholic 5,000+ posts]

I read a study that said underpowering caused cancer in 8 out of 10 lab rats. Also made 3 of them pregnant.

 

[vehementSPL 10+ year member]

My friend audio. You just stated that distortion doesn't damage subs at all and then you say clipped signal blew the speakers. a clipped signal (distortion) can cause thermal break down of a speaker. As far as being educated on everything that revolves around how a speaker works I am fairly educated but not an expert. But mike from shocker is FOR SURE an expert. Now as why tons of distortion with 30 watts didn't do anything is cause there is a point at which even if the subs don't move. The wire itself (voice coil) can handle x amount of amperage. so yes 30 watts on a 1000 watt speaker can not melt the coil. BUT a extremely clipped 750 watts on a 1000 watt speaker will blow it before a clean 1500 watts on a speaker will. You can argue till you are blue in the face. The current test you are referencing has NOTHING to do with what I am saying . if you took strait dc current and ran it through a 1000 watt coil but only 2 amps wouldn't do anything to the coil but 60 amps would. Also speaking of dirty wattage. I am PRETTY SURE lower ohms on amplifiers even at the same wattage puts out more amperage which high amperage will "open" a coil much more effectively then voltage. but THAT is theory. I don't know for sure

 

[vehementSPL 10+ year member]

And lets say by some chance i was incorrect explain this to me. I can run test tones to my subs for about 15 to 20 seconds before getting COIL SMELL. Now on a song that has a pretty solid tone or a small rift in it. I can play pretty much forever and no smell (now I know first response will be that cause the tone is putting a lot more power to the sub. i have tested the amplifier output and on the song and test tone is almost identical RMS wattage output)So explain a bit of that. See a test tone becomes clipped past half volume. I can turn it up to 3/4 and no gain just coil smell but the music will play at 3/4 with same wattage but doesn't gain full output till the 3/4 mark. Also one more thing. In a few walls we have done. on test tones lets say (35hz) you can turn it up till it maxes out then go two volume clicks past that then the subs start making weird noises and every notch you turn it up past that the sub moves less and less.

 

[_PuNiShEr_ 10+ year member]

audioholic you might as well give up. Some people just like to fight. You're right. They are wrong. Hopefully people will not be misguided by their information. If they are you tried and that's all you can do.

peace

Pun

 

[audioholic 5,000+ posts]

BUT a extremely clipped 750 watts on a 1000 watt speaker will blow it before a clean 1500 watts on a speaker will.

You have absolutely no proof of that, nor can you prove it. Because it, and you, are wrong. Clear enough for you? Then prove it Einstein. You cant, and you wont. I dont give a damn what you think M ike at Shocker said, distortion does not cause thermal failure, wattage does.
Im starting to regret taking back the idiot comment. I never stated 'distortion' blew the speaker in my example. Do you have a mental developement problem?

Its like talking to a wall (one that is sealed all the way around).

 

[audioholic 5,000+ posts]

See a test tone becomes clipped past half volume. I can turn it up to 3/4 and no gain just coil smell but the music will play at 3/4 with same wattage but doesn't gain full output till the 3/4 mark.

Seriously... do you believe your own bullshit? Or is this just an attempt to get attention? I doubt even cotjones is this dumb.
Test tones become clipped past half volume.... priceless. lol! So tell me fine sir, how does the amplifier know when it is receiving a 'test tone' and when it is receiving 'music'? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif Its gotta know when its suppose to clip early, right? Its official, I take back taking back my idiot comment.

 

[Death By Bass 10+ year member]

You have absolutely no proof of that, nor can you prove it. Because it, and you, are wrong.

and this kiddies, is why you shouldn't take drugs!

lol

edit: audioidiot, you clearly have no idea whatsoever what you're talking about...

its kinda sad actually.

 

[delvryboy 5,000+ posts]

Seriously... do you believe your own bullshit? Or is this just an attempt to get attention? I doubt even cotjones is this dumb.
Test tones become clipped past half volume.... priceless. lol! So tell me fine sir, how does the amplifier know when it is receiving a 'test tone' and when it is receiving 'music'? //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif Its gotta know when its suppose to clip early, right? Its official, I take back taking back my idiot comment.

I'm going to add to this.... the 750w clipped amp has about the same ability as a unclipped 1500w amp to blow a 1000w rms speak. In fact, I'll give the edge to the 1500w amp.

 

[vehementSPL 10+ year member]

My friend I was talking about in my particular setup. the way my gains are set half volume is where it maxes out on test tones. I wasn't referring to all setups. If you have enough signal and have the gains set up your volume can max out 1/10th of the way up. And just cause I disagree with your theory on this doesn't make me an idiot again. And I realize a sub will only break due to mech and thermal . But a heavily clipped signal and cause thermal breakdown

 

[audioholic 5,000+ posts]

and this kiddies, is why you shouldn't take drugs!
lol

edit: audioidiot, you clearly have no idea whatsoever what you're talking about...

its kinda sad actually.

Then prove it. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif Go on smart guy, prove Im wrong. You cant. You wont. You'll slink away just like last time. You dont have the guts, or the brains. Im daring you to even try.
Im sure its obvious to anyone reading this thread who knows what they are talking about, and who is just being a little cry baby bitch. //content.invisioncic.com/y282845/emoticons/wave.gif.002382ce7d7c19757ab945cc69819de1.gif

My friend I was talking about in my particular setup. the way my gains are set half volume is where it maxes out on test tones. I wasn't referring to all setups. If you have enough signal and have the gains set up your volume can max out 1/10th of the way up. And just cause I disagree with your theory on this doesn't make me an idiot again. And I realize a sub will only break due to mech and thermal . But a heavily clipped signal and cause thermal breakdown

You like to make claims, but never explain them. You simply state a clipped signal can cause thermal breakdown, yet you do not explain how/why you feel this is possible. 'Clipping' will only lead to thermal breakdown IF the clipped signal passes more current through than the speaker is capable of dissipating the heat from. The clipping, in and of itself, is not the problem. The WATTAGE is the problem.
Disagree'ing with me is not what makes you an idiot. Its that you are attempting to look like a well versed person on the topic, when its clear to people who do know whats going on that you only grasp the very most basics of the topic at hand. And much of that you understand incorrectly. This is not a slam, its me stating the truth. You simply do not know as much about this subject as you aparently think you do. Maybe if you stopped arguing so much you'd realize that.

I'm going to add to this.... the 750w clipped amp has about the same ability as a unclipped 1500w amp to blow a 1000w rms speak. In fact, I'll give the edge to the 1500w amp.

Finally someone else with a brain speaks up. As you are alluding to, a clipped amplifier can easily output double its rated power. So much for 'underpowering' the speaker when it blew.
Adding that line to my sig is probably the single greatest thing Ive done on this board. It brings out the idiots in full force.

 

[Immacomputer 10+ year member]

Vehement, you are pretty far off on your understanding of thermal failure. Audioholic is correct that there is either going to be thermal or mechanical failure. Distortion can lead to either one of these because of the power of the signal, not the shape.

It's all about signals and how much power they carry. When an amplifier is rated for power, it's done so at a low THD level. This is where the manufacturers expect people to use at their max listening volumes. The amps are NOT limited to that amount of power though. They can produce much more power but the signal becomes distorted and it sounds terrible so the amps' max output (in wrms) is not rated there and instead is rated at the lower THD limits. So, because an amp is rated at XXX watts RMS does NOT mean it's limited to that power output.

As you increase the distortion, the amplifier is still amplifying but the signal is beginning to square off due to the characteristics of the transistors used. When you have reached the maximum potential output of the amplifier, the wave will be completely square but with the same peak amplitude of its unclipped tone of same frequency.

So where does the extra power come from if it has the same amplitude? It comes from all the upper order harmonics that are associated with the signal and we can calculate it using a Fourier series equation but that's tedious and boring. Instead, let's look at the frequency spectrum of both a clean 45hz signal and a clipped 45hz signal.

Let's look at each signal in the frequency domain and time domain starting with the unclipped version of the 45hz tone:

Unclipped sine wave in time domain:

Unclipped sine wave in frequency domain:

Slightly clipped sine wave in time domain:

Slightly clipped sine wave in frequency domain:

Fully clipped square wave in time domain:

Fully clipped square wave in frequency domain:

Now focus on the frequency domain spectrums as they tell us the power (in dB) over the frequency. You can see that there is blatantly more power (purple stuff) across the board on the clipped signals. You can also note that the fully square wave has a fundamental increase in power by 3dB (look at the cursor position)!

With those graphs, it would be hard for me to believe that you still don't understand that it is the extra power from the signal and not the shape of the signal (although the shape is what brings on the extra power). It's also not a DC component that enters the signal. If it were, the time domain expression would not be centered at 0 but would be floating like in this ghetto MSpaint sketch I did:

That is a sine wave on the left with a 0v DC bias (no DC at all) and on the right is a sine wave with a 1v DC bias applied. This is NOT what happens when a signal clips.

I hope this helped.

 

[vehementSPL 10+ year member]

Ok Well I owe him an apology but still doesn't justify his attitude. And i wonder why some extremely intelligent people are speakers still swear distortion destroys subs? and I am still confused why on one of our builds his btls once they get to max volume and you keep turning it up and starts making a weird wobble nose and loses volume and quits moving as much. And let me ask this. You said the end of the spectrum become flat when a sqaure wave is introduced. Now this is honestly a question. In theory wouldn't the sub not move as much thus less cooling? I could be incorrect

 

[vehementSPL 10+ year member]

And audio I never claimed to be an expert on the subject. I even stated that i wasn't

 

[Immacomputer 10+ year member]

And let me ask this. You said the end of the spectrum become flat when a sqaure wave is introduced. Now this is honestly a question. In theory wouldn't the sub not move as much thus less cooling? I could be incorrect

When you take into consideration the frequency that you're playing, and that no motor has that kind of control of it's moving mass, then it's really doubtful that the awkward change in motion will cause much heating issues.

Think about it like this: if the speaker truly played a square wave, then it would have to have an almost infinite acceleration to reach the peak and then it would have infinitely decelerate to hang for 1/x seconds and then infinitely accelerate back down. It's just not going to happen in real world. In reality, the speaker will have to accelerate to the peak and then it will have to be restored quickly during the "freeze cycle" (the plateau of the signal) while the moving mass of the driver still wants to move beyond the peak. This will cause it to have an odd shape but I doubt it would resemble a pure sine wave or a pure square wave.

 

[Megalomaniac 5,000+ posts]

You have absolutely no proof of that, nor can you prove it. Because it, and you, are wrong. Clear enough for you? Then prove it Einstein. You cant, and you wont. I dont give a damn what you think M ike at Shocker said, distortion does not cause thermal failure, wattage does.
Im starting to regret taking back the idiot comment. I never stated 'distortion' blew the speaker in my example. Do you have a mental developement problem?

Its like talking to a wall (one that is sealed all the way around).

truf yo. here is something i wrote in my underpowering thread(mmacompter helped me understand too) at mp3car.:

I tried debating some more over there but some people just dont get it when it comes to a technical level. I described how a clipped signal becomes a square wave and the harmonics with it carry more power than a standard sine wave, which is the reason a driver will heat up quicker.

As long as you dont send a clipped signal to driver and you are within thermal limits, you should(will) be fine //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

actually here is a 45hz extremely clipped signal

http://media.putfile.com/45hz-clpped

If i had used the same track on the test i did(my particular exact setup) nothing would have happened...to the sub atleast.

The amp is capable of 70watts rms I was only giving 30watts to sub. even with the clipping lets say(to make it easier) that a square wave uses double the power than a sine wave. so for that 30watts and playing that track the amp would "try" to produce 60watts because of that particular signal. either way i am within the amp's limit(might have gotten warmer) and I am COMPLETELY within the Mag's(sub) thermal limit(i have gave this sub 1600+ watts before on music, but average 800watts daily)...i know watts isnt necessarily heat but you get the idea.

now had i used a more powerful amp like a 500+watt amp then i could see the mag get damaged some.

just goes to show that as long as you are within thermal limits of a driver it wont take damage...no matter how bad it sounds :lol: