Hair trick

[Boomin_tahoe 5,000+ posts]

What area are the shows y’all are talking about?

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There might be a few or some in your neck of the woods.

 

[Water Bear]

Ok.... Lower frequency bass notes tend to have a longer wave length.
So it causes the amp to pull power for a longer period of time.

A bit better for you hispls?

Your egotistic need for everything to be to the utmost perfection to even be considered correct is annoying at times.

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I did some research to settle this question.

Energy and power of a signal.

If T is allowed to be any unit of time, the powers may differ. The power integral works out to be:

1/2 - sin(2kT)/4kT.

If T is very large, then the power of two different sine waves approaches the same value. If time has units of seconds, then even after 1 second the power of a roughly 32 hertz sine wave minus the power of a roughly 60 hertz sine wave is not more than 1/40. Since both powers are close to 1/2, the powers are already pretty close even after a second. (In other words both waves have a power which is about 20 times larger than the difference between their powers).

Note: Power here is in units of Watts, and as long as the amplitudes of the two waves are the same, the results of these calculations doesn't change *much*. I assumed the amplitude was 1 for simplicity. If the amplitude is A, then the power becomes A^2 times the above function: A^2 [ 1/2-sin(2kT)/4kT ]. So the ratio of the difference of the waves' powers to their actual power would still be 1/20 after 1 second.

 

[Papermaker85 5,000+ posts]

I did some research to settle this question.
Energy and power of a signal.

If you look at the third equation he has for the power of a signal, it is easy to see that the power of a sine wave does not depend on its frequency if T is a fundamental period.

This is because the fundamental period T of sin(Kx) is 2 pi / K, and the integral from 0 to T of sin^2(Kx) equals pi/K. Multiply this by 1/T and you get 1/2. Since this doesn't depend on K, the power consumption of two sine waves of differing frequencies is the same.

If T is allowed to be any unit of time, the powers may differ. The power integral works out to be:

1/2 - sin(2kT)/4kT.

If T is very large, then the power of two different sine waves approaches the same value.

good job on hte research. I can't get these tards to do any research.

 

[Water Bear]

good job on hte research. I can't get these tards to do any research.

I made some edits to improve clarity. I don't think I need to include the comparison when T is a fundamental period because it's kind of confusing. Glad you appreciate the research!

 

[Papermaker85 5,000+ posts]

I made some edits to improve clarity. I don't think I need to include the comparison when T is a fundamental period because it's kind of confusing. Glad you appreciate the research!

time should be you're constant for any measurement of energy.

 

[The_Quiet_One 10+ year member]

I did some research to settle this question.
Energy and power of a signal.

If T is allowed to be any unit of time, the powers may differ. The power integral works out to be:

1/2 - sin(2kT)/4kT.

If T is very large, then the power of two different sine waves approaches the same value. If time has units of seconds, then even after 1 second the power of a roughly 32 hertz sine wave minus the power of a roughly 60 hertz sine wave is not more than 1/40. Since both powers are close to 1/2, the powers are already pretty close even after a second. (In other words both waves have a power which is about 20 times larger than the difference between their powers).

Note: Power here is in units of Watts, and as long as the amplitudes of the two waves are the same, the results of these calculations doesn't change *much*. I assumed the amplitude was 1 for simplicity. If the amplitude is A, then the power becomes A^2 times the above function: A^2 [ 1/2-sin(2kT)/4kT ]. So the ratio of the difference of the waves' powers to their actual power would still be 1/20 after 1 second.

Can you guarantee the difference in amplitude in signals is the same for a sub playing a 20 Hz and a sub playing 40 Hz? That's one potential logical fallacy when trying to discuss this topic.

You're dealing with an electro-mechanically coupled system at low frequencies (read: A convoluted tangle of dynamic magnetic fields and current, induced and applied) Assuming for a second we are only discussing the comparison of acoustic energy between two discrete frequencies in one simple setup, I still don't think it's quite that easy to make a definitive claim.

It was a good a pedagogical exercise at the very least.

 

[Water Bear]

Can you guarantee the difference in amplitude in signals is the same for a sub playing a 20 Hz and a sub playing 40 Hz? That's one potential logical fallacy when trying to discuss this topic.
You're dealing with an electro-mechanically coupled system at low frequencies (read: A convoluted tangle of dynamic magnetic fields and current, induced and applied) Assuming for a second we are only discussing the comparison of acoustic energy between two discrete frequencies in one simple setup, I still don't think it's quite that easy to make a definitive claim.

It was a good a pedagogical exercise at the very least.

It depends on a lot of things out of my control. If we pretend that the output voltage from the head unit for a ~30 hz and ~60 hz signal are about the same, then yes I think so. I'm not a sound engineer, I just do math.

 

[The_Quiet_One 10+ year member]

It depends on a lot of things out of my control. If we pretend that the output voltage from the head unit for a ~30 hz and ~60 hz signal are about the same, then yes I think so. I'm not a sound engineer, I just do math.

I just do Physics. I'm not knocking your post, but you did not settle the question. Though you did provide some good information for people who might be interested in one technical aspect of the question at hand.//content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif Just remember to look at the big picture. //content.invisioncic.com/y282845/emoticons/toast.gif.bc0657bf54b9ee653b6438524461341e.gif

 

[los33 10+ year member]

It depends on a lot of things out of my control. If we pretend that the output voltage from the head unit for a ~30 hz and ~60 hz signal are about the same, then yes I think so. I'm not a sound engineer, I just do math.

I just do Physics. I'm not knocking your post, but you did not settle the question. Though you did provide some good information for people who might be interested in one technical aspect of the question at hand.[emoji106] Just remember to look at the big picture. //content.invisioncic.com/y282845/emoticons/toast.gif.bc0657bf54b9ee653b6438524461341e.gif

The point in my previous post was yes no matter the frequency each sine wave will use same amount of power.
But music is not a sine wave, but the music people use for car audio and hair tricks so to say have certain notes that can be considered a mini sine wave or a longer wave length.

If you have those types of waves thru out the song you will deplete your power supply faster then what the actual power source can supply.

Not to forget most have two amps or more.

Your math is correct yes, but simple math cannot be used as the actual function in the equation changes as new elements are added.

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[hispls 5,000+ posts]

Can you guarantee the difference in amplitude in signals is the same for a sub playing a 20 Hz and a sub playing 40 Hz? That's one potential logical fallacy when trying to discuss this topic.
You're dealing with an electro-mechanically coupled system at low frequencies (read: A convoluted tangle of dynamic magnetic fields and current, induced and applied) Assuming for a second we are only discussing the comparison of acoustic energy between two discrete frequencies in one simple setup, I still don't think it's quite that easy to make a definitive claim.

It was a good a pedagogical exercise at the very least.

It's very easy to make a definitive claim. You should learn at least the very basics of electricity. 1W of true power at 20hz is the exact same flow of energy as 1W at 40hz or 40 Mhz. If you wish to disprove Joule's Law post the formula to refute it. The only time that power over a period of time makes wavelength relevant is if we are discussing very small units of time (below 1 second if we're talking about 20-100hz) and even then the difference of the longer wave losing a 20th of a cycle isn't going to mean "better buy more batteries" and even then depending where each waveform starts and stops the flow of energy could still be identical.

The point in my previous post was yes no matter the frequency each sine wave will use same amount of power.

You specifically said that lower frequencies draw more power because they have longer wavelengths. If you're trying to say something else then or now you're doing a terrible job of explaining it.

And how we determine power was figured out in 1841. It's not up to debate because you're trying to save face here.

https://www.allaboutcircuits.com/textbook/direct-current/chpt-2/calculating-electric-power/

 

[Water Bear]

I just do Physics. I'm not knocking your post, but you did not settle the question. Though you did provide some good information for people who might be interested in one technical aspect of the question at hand.//content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif Just remember to look at the big picture. //content.invisioncic.com/y282845/emoticons/toast.gif.bc0657bf54b9ee653b6438524461341e.gif

I see what you're saying, but it's outside the scope of the question I was trying to answer. If you have two sine waves whose only difference is the frequency, and not the amplitude, then their powers are about the same after a few seconds. But yes you are right, if the amplitudes are different then you can forget everything I posted earlier //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

The point in my previous post was yes no matter the frequency each sine wave will use same amount of power.
But music is not a sine wave, but the music people use for car audio and hair tricks so to say have certain notes that can be considered a mini sine wave or a longer wave length.

Music will definitely change things (to the point where my previous post just goes out the window completely). I feel like there's good odds that bass heavy techno or rap just plays a pure bass note of whatever frequency, though. So it might be close, but I dunno.

All of this, again, with the caveat that I have never studied this stuff in particular. My degree is in math, not acoustical engineering.

 

[Papermaker85 5,000+ posts]

The point in my previous post was yes no matter the frequency each sine wave will use same amount of power.
But music is not a sine wave, but the music people use for car audio and hair tricks so to say have certain notes that can be considered a mini sine wave or a longer wave length.

If you have those types of waves thru out the song you will deplete your power supply faster then what the actual power source can supply.

Not to forget most have two amps or more.

Your math is correct yes, but simple math cannot be used as the actual function in the equation changes as new elements are added.

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wtf are you talking about?

 

[Papermaker85 5,000+ posts]

I just do Physics. I'm not knocking your post, but you did not settle the question. Though you did provide some good information for people who might be interested in one technical aspect of the question at hand.//content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif Just remember to look at the big picture. //content.invisioncic.com/y282845/emoticons/toast.gif.bc0657bf54b9ee653b6438524461341e.gif

out of context. we are talking about acoustic energy.....

 

[The_Quiet_One 10+ year member]

It's very easy to make a definitive claim. You should learn at least the very basics of electricity. 1W of true power at 20hz is the exact same flow of energy as 1W at 40hz or 40 Mhz. If you wish to disprove Joule's Law post the formula to refute it. The only time that power over a period of time makes wavelength relevant is if we are discussing very small units of time (below 1 second if we're talking about 20-100hz) and even then the difference of the longer wave losing a 20th of a cycle isn't going to mean "better buy more batteries" and even then depending where each waveform starts and stops the flow of energy could still be identical.

I really respect your thoughts and opinions on a lot of things, but to think you can model the dynamics using only joules law to evenly compare playing different notes is naive at best. Perhaps instead of being snarky you should learn the very basics of constructing a Physics based model instead of falling back to a gross oversimplification and not to mention a complete miss to the argument I presented? Correct me if I'm wrong this argument started out from someone different notes required more or less power, and my posts have been an attempt at pushing the discussion towards why one could see differences in the electrical draw of the amp between different notes?

Did I say that the clamped power was the same between different notes? If you truly understood basic electricity you would know my post was practically screaming you cannot guarantee the delivered power was the same for two different notes.

Like I was trying to get across to water bear. We are not modeling the energy difference at the RCAs inherent to the electrical signal transmitted by the DSP/HU. We are modeling the underlying physics of the subwoofer/amplifier system to see if it's feasible that the electrical draw would be different at different tones. Granted that itself is a pretty gnarly simplification for most daily scenarios, but it could be swallowed a tad easier if one took the FFT of various bass heavy music and analyzed a signal in frequency space.

You are dealing with a highly dynamic system in which fundamental electrical characteristics change over stroke. Like it or not at low frequencies this likely means considerable difference between notes such as 20 Hz or 40 Hz. To begin to even make a definitive claim requires some complex modeling of induced back emf to try and quantify some dynamic thevenin impedances. At that point you might could make some gross guesses as far as the lower bound in instantaneous power requirements. Otherwise you're telling me load impedance is constant at all target frequencies for the subwoofer system (driver and enclosure)? I won't even ask about phase dynamics...//content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif

So to sum up my argument: I don't know. It's hard to make a definite claim. Determining power output from an amplifier is difficult with dynamic impedances in an AC system. That dynamic impedance is going to mean different power delivered by the amp and therefore change the electrical requirements at that time.

FYI Look deeper into the power equation you posted. You don't think there is a frequency dependence built into there in this use case?

Or better yet. Grab an O-Scope and a couple DMMs and prove me wrong. Howabout I put money where my mouths is? 100 bucks if you prove me wrong through empirical results. I'll pay in silver, crypto, or cash, your pick.

 

[The_Quiet_One 10+ year member]

out of context. we are talking about acoustic energy.....

How's the big picture out of context?//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif Acoustic energy is way different than energy contained in the input electrical signal, and they are both different than the energy requirements needed to recreate a dynamic or sinusoidal signal using a subwoofer. You all need to get your energy and power ducks in a row.//content.invisioncic.com/y282845/emoticons/toast.gif.bc0657bf54b9ee653b6438524461341e.gif