To put things in perspective, just being alive requires pollution and expenditure of energy.
Early optimization is considered a bad practice in some disciplines.
I wouldn't think about energy saving too much. I saved a lot already by living my life minimally and not driving a car.
Leaving a class-D amp on is not going to hurt. By living a life minimally, you save a lot more energy than you would by turning a class-D amp off when you don't use it.
Although global warming looks bad in the short term, we can try to terraform earth over the next few hundred years by planting more trees and controlling climate with technologies.
It may cause pain in the short term, but it is not going to threaten humanity's survival. We have technologies to overcome global climate changes. We just need to gather enough resources to actually implement them.
We are using less than 1% of earth's potential. Humanity is tapping into less than 1% of its potential. Over the next few hundred years, it will be overcome.
In the future, through technologies, we will turn deserts into forests.
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In the electronics world among us, engineers, technicians, and designers, among others, all have personal biases, and perferences, just as anybody would.
They are all human, of course.
Depending on how and when they were taught, also creates a certain bias of sorts.
This then leads to the human professor that you mentioned.
In today's world, many sources of information are gathered and shared from the oh-so-holy internet, unlike decades ago, when I had a bald-headed and very strict teacher in a classroom, overseeing us students and our progress.
We were taught from the books - the rule of laws - fundamental, factual information which naturally and to this day, is the basis for our knowledge.
In my observations, particularly since the birth of the internet, I've sensed a trend towards "new facts" and "observances", which in some cases are justified, while others are nonsense centered on beliefs, obviously not based on those books that were and still are the basic rule-of-laws that cannot be disputed.
To conclude, this "audio engineer" you mentioned, I don't know his qualifications or experience, since you gave no name for me to look up, thus I cannot successfully make a determination of his qualifications.
wiseoldtech, You can't assess him anyway because I and he speak an asian language as the native language. English is my second language. Everything about him is written and recorded in my first language.
I don't want to go too deep about him.
The gist is that woofers become more responsive with stronger amps, especially when those woofers are heavy. But, until I actually test strong and weak amps side by side, I won't be able to tell you how much of a difference there is for my speakers. At least, he spoke from his own experiences. Do you have any definite experiences to refute his claim?
Anyway, it's good to have some headroom for more power. 50W is not bad. At least, knowing that I have enough headroom to avoid distortions gives me piece of mind.
I don't want to go too deep about him.
The gist is that woofers become more responsive with stronger amps, especially when those woofers are heavy. But, until I actually test strong and weak amps side by side, I won't be able to tell you how much of a difference there is for my speakers. At least, he spoke from his own experiences. Do you have any definite experiences to refute his claim?
Anyway, it's good to have some headroom for more power. 50W is not bad. At least, knowing that I have enough headroom to avoid distortions gives me piece of mind.
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Although the measured output may be small, the power required to damp a heavy woofer may be much higher in transient bursts, in order to damp the cone mass and reactance of the driver. The driver effectively becomes part of the global feedback network.
However this hardly applies to low mass and reasonably well damped speakers.
However this hardly applies to low mass and reasonably well damped speakers.
I concur with wiseoldtech.
And I'll be blunt, because I abhor misleading nonsense that just confuses and misleads people who are trying to learn: the claim that "weak" amplifiers cannot "accelerate/ decelerate fast" is complete nonsense.
Reality is that the speed of an audio amplifier is defined by exact engineering parameters such as its unity-gain bandwidth and its slew rate, and its rise and fall times. NONE of these parameters is directly related to its output power. You can make a milliwatt amplifier fast enough to handle gigahertz signals, or a kilowatt amplifier so slow that it cannot cope with 1 kHz. "Weak" does not mean slow, and "powerful" does not mean fast when it comes to audio amplifiers.
This simple fact - that any competent audio engineer can easily build fast "weak" amps and slow "strong" amps - completely blows the claim out of the water. It does not matter who made the original claim, whether he/she was professor, angel, or god; the claim is wrong, and that is easily proved on the workbench.
Appeals to authority ("famous guy said so") don't work in science, engineering, or math, where a simple disproof is all that counts. It doesn't matter if the claim came from a Nobel Prize winning professor and the disproof came from the janitor; a disproof is a disproof, regardless of whom it came from.
This is exactly why science, math, and engineering have progressed incredibly over the last couple of thousand years, while other areas of human culture (which *do* depend on appeals to authority) remain pretty much as they've been for thousands of years, limited by our own human failings. Authorities (like everybody else) make mistakes; reality doesn't. When we rely on reality (experiment, engineering, math), we make more progress than we do when we rely on authority (i.e., some famous person's personal - and possibly faulty - beliefs.)
Please note that I am not in any way criticizing you personally, CowCat - I believe that you believe what you wrote. However, it is in fact quite completely wrong, and we are all better off if we dispose of it immediately, and put it where it belongs, in the trash-can of nonsensical audio myths, along with other nonsense such as the benefits of mpungi discs:
1) Shun Mook Mpingo Disc | highend-electronics, inc.
2) Getting Shun-Mooked - Audiophile Review
-Gnobuddy
Now, that clarifies things.
Yes, a higher wattage amp will "control" the speaker better than a small one.
Your previous post about the speed and size of amps was not clear about that fact, so now I can better understand what you meant.
Amplifier "damping factors" and power supply design all factor into this "control", as well as speaker design.
Can you explain how a higer wattage amp controls speakers better?
return energy from speaker's moving mass is better controlled by stronger amp. If you have weak amp, it will be over run by speaker's return energy. That is a case with big woofer speaker.
Also, CowCat, do you understand crest factor in music, various music have various crest factor and defines how much power you should have to play it comfortably...
Maybe similar to car, but very strong car...
Also, CowCat, do you understand crest factor in music, various music have various crest factor and defines how much power you should have to play it comfortably...
Maybe similar to car, but very strong car...
I have a tpa3116 black board on 24/7 for last few years. in a alu case which surprisingly gets a bit warm in my warm little room, even when not being used. i wonder if noise floor of dac means amp gets a bit of low audio signal of noise all the time and so amp is always working a little... hmm??? its connected to computer so half to most of the day its doing work for movies or music i listen too.
anyway point being its doing great! seams to be wellmade these tpa3116 black boards 😀
anyway point being its doing great! seams to be wellmade these tpa3116 black boards 😀
I'd like to see pictures of your amp and your amp's power supply.
Well, I have been powering a big old pair of 15 inch vintage Tannoys with a tiny tda7297 for the last 5 years,
There is a misunderstanding hidden here. This very often happens when we use words to describe a situation that is actually best described with mathematics.
If you drive the woofer with a larger power, then the back EMF (what you called return energy) is also large.
If you drive the woofer with a lower power in the first place, the back EMF is correspondingly smaller.
The net effect is that a 2 W amp and a 200 W amp produce exactly the same amount of woofer damping, regardless of woofer moving mass, as long as both amplifiers are kept out of clipping, both have the same output impedance, and nobody is thwacking the woofer cone with a stick to create external created back EMF. 🙂
This happens because the mathematical equations that describe amplifiers, as well as loudspeaker motion and back emf, are linear - drive to the speaker, and the speakers back-emf response, are directly proportional to each other, until either the amp or the woofer is pushed to its limit and starts to clip.
But if you feed the same waveform into the same speaker at 2 watts or 20 watts, and amp and speaker do not clip in both cases, then you get exactly the same woofer cone motion, scaled up or down accordingly in amplitude. Damping is the same in either case.
If you turn the 2 W amp up until it's deep into clipping, then certainly it will do a worse job than an un-clipped 20 W amp. And if you turn the 20 W amp up until it pushes the woofer itself into clipping, it will do worse than the 2 W amp driving the unclipped woofer.
But that's an entirely different question. It has nothing to do with some inherent "slowness" of low power amps, but rather with the amount of power needed to generate the SPL you desire from your woofer, in your listening room.
Audio watts have become so cheap in recent years that its rarely a problem obtaining enough watts to drive the woofer. If your tastes run to loud, deep bass, the more expensive problem is finding a woofer that can handle the amount of power needed to create that SPL over those frequencies.
-Gnobuddy
In my living room I run a PC into USB DAC into 12inch-50WRMS driver.
Although not loud it does sound OK.
@Gnobuddy, it is not only electrical return energy, we have also mass of the cone and spring...
The mass of the cone and the suspension "spring" cause the cone to oscillate and move over and beyond the driving force from the amp. The voice coil generates electrical energy in response to this excess motion (Lenz' law, or more properly, Maxwell's equations.)
So it IS the mass of the cone and associated compliance that creates what you're calling the "electrical return energy" we're talking about.
And this "electrical return energy" (back EMF) is proportional to the driving voltage from the amplifier. The bigger the drive signal from the amp, the more the cone mass moves, and the more back EMF it generates.
The result is that, as long as both amp and speaker are kept operating in their linear regions (no clipping), the big and the small amp control the woofer exactly equally.
An analogy might help. Suppose you go to a park where they have a tyre hanging from a chain, for kids to swing in. If you push the swing gently, it only takes a small force from your hands to stop the swinging motion. If you push the swing forcefully, it takes more damping force from your hands to stop the motion.
In the analogy, your hands are the amplifier, and the swinging tyre is the speaker moving mass and suspension. If you drive it harder, you have to deal with more energy to damp it. If you drive it more softly, you have to deal with less energy to damp it.
This is why a small amp, driving the speaker gently, damps it just exactly as well as a big amp driving the speaker more forcefully - as long as both amp and speaker are kept out of clipping.
-Gnobuddy