The actual used amps are a consequence of the voltage supplied and the impedance of the load. The current rating of an amplifier is how many amps it can supply before it distorts/burns out
Finally--someone gets it!!!! Fact the Power Supply is the Power in Audio Power Amplifier. Also it is the largest and most expensive section of a audio amplifier
Voltage is the forcing function to do the work, just as pressure is what forces the current flow through a garden hose. The amount of flow depends on the obstructions or resistance in that circuit - whether electrical or hydraulic.
It's a bit more than that. SS amps have a reservoir (capacitors) that stores voltage and uses them when big impact sound passages (low end bass response) is created at the speaker. The lower the frequency the speaker needs to produce, the more current is needed from the speaker. Thus more current that is needed from the amplifier. It is all about (what is known as) continuous current (power). Valve (tube) amps do not use capacitors the same way (mostly) as a SS amp. This is one of the reasons that tube amps are more expensive. Tubes generate very high voltages (far more than SS amps) and have a continuous power level that can maintain better current draw demands. However, SS amps have higher combined total watts output than tube amps. Both have high values for continuous power to the speaker (although the topology between the amps are different).
Infinity 9 Kappa - I learned the hard way when purchasing these speakers which dipped to a minimum .5 ohm and then sat on average under 3 ohms. Add to that their 84 dB sensitivity and my current 200 'watts' per channel amplifier shutdown on me daily 😢. So yeah, 'watts' mean shit! You must know your speakers 'real' in-use resistance (ohms), as well as their actual sensitivity, as well as your desired listening levels.
That would be to service those persons of a visual learning discipline. I thought he very clearly articulated a relatively complex concept, but as an engineer it’s something I was already acutely aware of and I’m personally not visually inclined in my learning methodology. I think the whiteboard would certainly service some persons but I also think his delivery on these videos is very informal and focused on entertainment as much as education. If he were to draw it out on whiteboard, I could see a certain sector criticising for being condescending or pedantic. Sometimes on social media, you just can’t win. Paul’s deliver on these videos is genuine and faithful to his personality. For those that want to delve deeper into the electronics and theoretical sciences, I’d suggest reading an engineering textbook on subject
It's an interesting topic with no end to the complication that can result. Most loudspeaker manufacturers give their speakers a "nominal" impedance rating, as the impedance changes by frequency. We tend to think about Ohm's law, but that technically applies only to resistance. With a speaker, you're also dealing with capacitance and inductance. Music is generally a complex mix of frequencies, which means that the amplifier is looking at different impedance for each frequency. As far as "high current capacity" in an amplifier, it's not just the overall power capacity of the power supply, but its ability to deliver that power across the load, which may be limited by internal components. Amplifiers with high current capacity are linear over a wider range of impedance in their ability to deliver power to the load.
The point is that current is voltage dependent not the other way round for given load , if you want to increase the current through a fixed load, you have to increase the voltage applied to it, you cannot create a circuit with fixed voltage with a fixed load and have a current control knob, electricity doesn't work like that. it is more complicated than that because analogue sound signals in a wire are AC and speaker loads are frequency dependent which is probably why high current AMP marketing term came in, but its smoke and mirrors if you want to increase the AC current through a load its the peak to peak AC voltage that had to increase.
Thank you Paul, this was the most technicaly informitive and therefore most useful video that I've seen from you to date. Keep up the good work! It turns out, I was looking at impedance kind of backward. I think. I thought a lower ohm speaker meant that it was easier to have higher voltage, hense the higher wattage rating from the amplifier and should play louder as a result of that increased wattage capability. But now I'm a little confused about which of these statements is true or false.. And why many people feel that lower ohms are better for higher performance, if it actually takes more amperes instead of less, to maintain the same voltage?
I know when you first hear it, it doesn't make sense, but its true. The lower the resistance, the harder the amp has to work. Its kind of like water pressure. Think of a standard 1 inch garden hose. Imagine the water pressure at your home is represented by volts, and the diameter of the hose is represented by amps. When you turn the hose on all the way, water usually shoots out 2 or 3 feet. If you need the water to go farther, you can put your thumb over the end of it, and increase resistance. You'll have less water coming out of the hose but it goes much farther. Now imagine getting some type of adapter that lets you attach a big 3 or 4 inch fire hose to your house. When you turn it on all the way, water won't shoot out at all. It may take a few minutes just to fill the hose up. You only have so much water pressure, and its not enough to overcome the drop in resistance. So, if you need to water your garden 20ft from the hose, your thumb is good enough. If you have to put out a fire, you need a bigger hose and a fire hydrant. Its not a perfect example, but its enough to get the basic idea.
@@AT-wl9yq This is a good explanation! But then, if lower impedance speakers are actually harder to drive, why do people feel they are better? Also, coming from higher end headphones, the high impedance cans definitely need more power to drive, VS the 'low' impedance, 32 ohm stuff for portable use. Good luck running my LCD-4 off a cell phone and they don't have outrageously low sensitivity, if I remember correctly. But 200 ohms and love power.
@@zackw4941 Your first question is easy to answer. They don't have a complete understanding of all the relevant factors, and they make judgments based on only what they think, or know. Your point makes sense. Its a counter intuitive concept, but once you understand all the variables, it all makes sense. As for your headphone question, I'm not an expert. I don't know headphones like I do regular audio. If I had to guess, the difference has to do with the application. Headphones are small speakers and work basically the same way. The big difference is in the environment. In a home audio setup, you sit about 8 to 10 feet away from the speakers. The speakers also have to energize the room you're in. The amount of air that the speakers in a home system has to move is thousands of times greater than what is required of headphones. Removing that major variable from headphones, it would make sense that others become more important. But that's my best guess. And my guesses are not always correct.
@@AT-wl9yq The major 4 ohm proponent I'm thinking of is Eric Alexander of Tekton Designs. He likens 4 ohm to a higher flowing head on an engine. He of all people should know what he's talking about. But either way, it seems that sub 8 ohm speakers have become basically the norm now, so their must be a reason they are favorable. Headphones are nice because you don't have to deal with a room and you can listen whenever you want. My LCD-4 setup is pretty speaker like, but there's still no substitute for cranking up a big pair of speakers when no one is around.
@@zackw4941 I've heard the argument you make in your post quite often in recent years. In my last post, I said this. "Your first question is easy to answer. They don't have a complete understanding of all the relevant factors, and they make judgments based on only what they think, or know." I'm going prove it to you right now. Never assume or guess. It will only get you into trouble. "He likens 4 ohm to a higher flowing head on an engine. He of all people should know what he's talking about. But either way, it seems that sub 8 ohm speakers have become basically the norm now, so their must be a reason they are favorable." Out of curiosity, I watched the Tekton video, along with a few others, and couldn't believe what I was seeing. Its no wonder why so many people have trouble with this. To start, when you buy a speaker, its not 4 ohms or 8 ohms. Those are averages. As you are playing music, the speakers resistance is constantly changing. It never just sits at 4 or 8 ohms. The amount of resistance an amp sees is bases on the frequency its asked to reproduce. Out of the entire range of frequencies a speaker is capable of playing, there is only one frequency where the speaker will provide a 4 or 8 ohm load to the amp. Think of a piano. Every key on the piano, when played, will show a different amount of resistance to the amp. The lower the note, the lower the resistance. Higher notes equals higher resistance. When looking at the specs for a pair of speakers, there are 2 things you need to see. The first is the average that I mentioned above (4 or 8 ohms). You should also see another number, and its more important than the average. Its the lowest amount of resistance the speaker is capable of showing the amp. For example, if you are comparing 2 pairs of speakers and one is rated at 8 ohms with a 4 ohm minimum, and the other speaker is rated at 8 ohms with a 3 ohm minimum, the speaker that drops down to 3 ohms is a much harder speaker to drive. Both are listed as 8 ohm speakers. For anyone to not include this information in a talk on amps and speakers is nothing short of criminal. I'm going to make a recommendation. From what I understand of youtube, including links to other web sites is not permitted, so I'll list where you need to go. Start by going to Vandersteen speakers website. Its vandersteen dot com. Then click on the resources tab. Look for something that says memorial page or Audio Perfectionist Journal (APJ). This will take you to links where you can actually download all the journals for free. The story behind APJ was someone wanted to start a new audio publication that provided information and reviews that didn't take money for advertising. He brought in one of the reviewers for The Absolute Sound to help out. Not long after that, the guy died unexpectedly. His family agreed to make all 15 or so issues of the journal free for anyone who wants to read them. I'm recommending this as a reference because its the best resource I've ever seen on high end audio. It would take the average person years to accumulate all the information he gives you. And its free. Everything we're talking about here, and far more, will delt with by someone who is much better at explaining things better than I can. If you are interested, its well worth your time.
Paul McGowan, you decreased the level of ignorance on this planet with a significant rate! Thank you, for all your videos! They are a great learning curve for all audiophiles.
Power = Voltage x Current. Current = Voltage / Impedance. Power = Voltage x Voltage / Impedance. Twice the voltage means 4 times the power in the same speaker impedance. Power is energy per time (1 Watt is 1 Joule per second) and the speaker cone effort of moving the air is ultimately about work.
Very correct! Amps is an outdated term still used today. Remember, the signal (analog voltage) is the voltage language the speaker interprets. The voltage current levels/impedance effect amplitude on the sound reproduction at the speaker (the work being done to reproduce the sound from the speaker drivers).
@@jayedgar2373 No power no sound. The 1st law of thermodynamics rules ultimately. When a power plant outputs 1 Joule of energy per second (1 Watt) it experiences losses through the path from the power plant generator to your speaker cone moving the air but ultimately some fraction of that 1Joule per second is what moves the air as energy per time. Most of the energy gets lost as heat...but the SPL you hear is all about Joules of work following the 1st law of thermodynamics. So power is what really matters when you want to move air molecules...
@@ThinkingBetter Where did I ever say "no power" or dispute the 1st law of thermodynamics? The signal path (from the front end through a preamp through to the amp) is known as the signal path. The pushing of the signal path is gained in output transformers (small, but able to produce on average 1.7v or 1.7 joule per coulomb = equation for impedance + input sensitivity) to the amplifier. The preamplifier to the amp requires anywhere from 0.5 to 2 volts (generally, but based on the preamp) input (to the amp) based on amplifier nominal impedance (sensitivity). The amplifier increases the voltage (output) to the speaker (measured through the amps input voltage). The amplification of that input signal is what the amp does. The voltage signal is very low into the amp actually. But to overcome (as you put it) impedance (connectivity, cable, speaker/input sensitivity and the electron field lines as they travel through the speaker cable), does require an amount of voltage to overcome any resistance in that circuit. The voltage required to overcome this resistance is rather small (but many things in the path can increase impedance). As Paul put it "the ohms rating on a speaker is not static". Neither is resistance/impedance. But the voltage to "push" that signal path at low volumes is rather quite small. The impedance at the speaker is based on how efficient the speaker is. A 90+db speaker is so little impedance, that it is measured in Mv (millivolts). In other words, that 90db speaker does a LOT with small amounts of voltage (highly efficient) to drive (work as you put it). However, 82 to 84db speakers require more power (primarily due to the woofers reaching lower extensions in frequency) to do the work as again you put it. They also have higher impedance (generally) in the hundredths of volts (generally). Speakers vary so much, that you can't put a label on any specific voltage required for the speaker to produce sound. Each speaker is rated (voltage requirements) to produces sound (minimum and maximum).
@@jayedgar2373 I didn’t say I disagree with you but just made the point that power is what makes a speaker cone move air. It’s like some people think torque is what accelerates a car. Power is what accelerates a car.
This was a good one. Though I wonder about the term watts in this context. I know the Ohms law and those things, but the signal has such a big variation so i wonder how it can be measured.
@Douglas Blake Yep. Each speaker interprets the voltages differently (crossover). So, pick a speaker and find out what the speaker is rated at. Just my 2 cents.
Paul ITS the current that drives magna pens when you have a high-powered high current amplifier is that correct current it should be a concern with the inefficient speaker like magna pans and 84 DB
You cleared that up for me - Thanks Paul I noticed the review mirror you have attached to your monitor. Keeps a view of your six & prevents the staff from sneaking up on you ! 😅
Volts is the pressure that causes charge movement. Amps is rate of flow of charge. Thus higher voltage is required to increase flow of current which will increase the wattage.
Voltage does not go into a speaker. Voltage is measure of potential difference between two points. Voltage is measured across the speaker, while current flows through speaker. A speaker has a rated impedance to current flow, measured in ohms (but actually a bit more complex than that, but a low frequency it can be considered mainly resistance). For given impedance (all things being equal), the higher the voltage across it the higher the current flow through it & higher the energy dissipated by it. The higher the voltage, the higher the current for given ohm rated speaker, & therefore the higher the watts (power) expended. It is the current flow through the speaker that determines the intensity of sound from the speaker, but to get that higher current you need to increase the voltage (V RMS value as audio is a AC composite wave) applied to speaker. Hence the amplifier is both amplifying audio signal presented to it (within voltage range before clipping distortion) while delivering sufficient current to drive the speaker without melting the high current output power transistors.
Great post but I am still confused about this (all my life). Volt, ampere and resistance are abstract concepts. As far as I know electricity is a movement of electrons. It would be nice if Paul could explain what actually happens physically with those electrons in a cable. Do more electrons pass through a cable at higher voltages? Is the movement greater at higher amps? etc etc. I have no clue, but would like to understand what is physically happening.
The electrons do not move like water through a hose. An audio signal is AC, the electrons move back and forth, moving very little. One electron shoves another, that electron shoves the next one, and so on. Higher voltages makes the electrons shove harder.
To put it into English, maximum power will be achieved when the speaker impedance matches the output impedance of the amplifier. An amplifier is capable of providing a certain voltage and a certain current. Maximum power is achieved when it does both at the same time. If the speaker impedance is less than that of the amplifier, then you’ll hit the maximum output current before maximum voltage is achieved. If the speaker impedance is higher than the amp, then max voltage will occur before max current is reached. An 8W amplifier designed for 8 ohms would produce 8V at 1A into an 8 ohm speaker. 8Vx1A=8W. If you use a 4 ohm speaker, the maximum current of 1A will happen at 4V. 4Vx1A=4W. With a 16 ohm speaker at the maximum voltage of 8V will pull 0.5A. 8x0.5A=4W.
There is a problem with your explanation, in that the output impedance of an amplifier is very low in comparison to the speaker load, and it isn't what determines the safe available current to the load. It's not the amplifier's output impedance that the speaker needs to match, it's the output voltage and current capacity, as you explain, but that is not a function of the amplifier's output impedance.
@@PlatypusPerspective There are two things to amplifier impedance. If a small signal impedance meter is connected across the amplifier output terminals, it will indeed read very low as the output impedance is artificially lowered by the application of negative feedback in order to provide damping amongst other things. However, this only holds true within the capabilities of the output transistors and makes no difference to the the amount of current they can ultimately source or sink and therefore the ‘real’ output impedance, which is the only thing of relevance here. If a 200W amplifier designed for an 8 ohm speaker really had an open loop output impedance of 0.01 ohms, the output devices would have to be able to handle 4000 amps and the power supply would need to be capable of 160KW assuming 100% efficiency. You also mention that it’s not the impedance that matters, but matching voltage and current. Ummm, Impedance = Voltage / current and power = voltage x current therefore you’re contradicting yourself. A speaker of equal power rating and impedance to the output of the amplifier will be matched in terms of voltage and current.
@@petesmith2234 The issue seems to be in application of terminology - in all my years of maintaining, designing and building audio equipment I have never known of anybody taking the output impedance of an amplifier to mean anything other than the small signal source impedance. When you said output impedance in your first sentence, evidently you were meaning rated load impedance.
@@PlatypusPerspective small signal impedance is irrelevant when I comes to an amplifier’s ability to deliver power. Small signal impedance is measured as the amplifier’s ability to resist a small signal generator trying to wiggle the output terminals up and down. It’s relevant in terms of damping, but that’s it. Power will always equal volts times amps give or take power factor, and maximum power transfer will always be when available volts x volts / amps equal load impedance. It has nothing to do with small signal impedance.
That was very helpful. So would the resistance rating of a speaker be analogous to the bore diameter of a trumpet and the voltage would be analogous to the PSI generated by the horn player who is somewhat analogous to an amplifier's transformer and ability for capacitance and recharging the caps? Except the resistance of a speaker is in flux where as with a trumpet relatively speaking there are no significant changes to the bore size increasing or decreasing resistance? I had to play along with the long winded analogy 😅 🎺
Even going further, the higher the resistance of the speaker, the more inertia has to be overcome giving you a harder hitting speaker but at lower volumes/energy levels will result in subdued dynamics. The opposite for low resistance speakers being more responsive but also requiring more energy pressure to get authoritative sound pressure. I have a small bore horn that is challenging for me to play softly but my larger bore I have more control over the dynamics
But we do not listen to sine wave test tone sweeps and speakers aren't purely resistive loads. That is how amplifiers are tested though. When playing real music through speakers, they perform quite differently in respect to power. And remember, bass frequencies from say 200 hz down take the vast majority of power. That's where high current comes in. (Think orchestral strikes) ALL speakers are not the same either. You have conventional drivers, electrostatics, planar magnetic s, horns. Each of those presents a very different load to the amplifier.Also, as the speaker plays, the woofer wants to go higher in impedance and the tweeter lower. It's not 100 watts is 100 watts is 100 watts. If that were true, all AVR's would have lots of bass slam, power and volume at their "600 watts output". I've yet to hear one that does. Some 100 watt amps have dual power supplies, massive filter capacitors, output transistors while others have one power supply, small filter caps and IC outputs. They are rated the same 100 watts though.One may have 2 db of dynamic headroom while the other has .5 db. I love how Paul try's to simply things, but often the answers are quite complex.
Sensitivity of a speaker is independent of the amplifier --- it is a physical attribute of the overall speaker itself. It depends on the type of crossover used, the construction of the drivers and the design of the cabinet enclosure. Once you start applying voltage to it it will produce sound at some loudness level (dB) and that will also depend on the type of voltage, particularly AC voltage and what frequencies you are transmitting. That's why some speakers do not produce much sound below a certain Hz. You've no doubt seen some speaker specs that give a -3dB output of say 40 Hz; it just has lower efficiency (sound output) at that tone. The loudness of a speaker however will depend on how much voltage is applied in concert with the speaker's sensitivity.
Ignore watt output and look at the actual power supply and that together with what class amp it is will tell you how powerful it actually is into the desired load. I.e a class AB amp that gives 2x 150w into 8ohms would require about 1000 watts to deliver 2x 300 watts into 4ohm. And to get 2x 600w into 2ohms it would need over 2000w power supply.. Class D is more efficient but for class AB this is true since they are about 50-60% efficient.
Here's a post from another PS video, relevant here too. It's all about the voltage, not the current! A "high current amplifier" is just a marketing ploy. You have a fixed load impedance, lets use 8 ohms. So for 200 watts we need an audio signal at 40 volts. ((40volts * 40volts) / 8ohms)= 200watts. And then we divide (200watts / 40volts)= 5amps of audio current. We have no control of the current. That is determined by Ohm's law. Let's do 406 watts ((57volts * 57volts) / 8ohms) = 406watts. Then (406watts / 57volts)= 7.1 amps. The current is what it is. To output more power you must supply more voltage to the speaker. If your amp can only produce 40volts of audio to the 8 ohm speaker, it doesn't matter if the power supply can produce 10amps, 100amps. You still only get 200watts at 8ohms. This is why basic car stereos can only produce about 3 watts yet the car battery can supply several hundred amps. The next step in car stereo was bridging. Here you are doubling the audio voltage produced. Today we use a switch mode power supply to get the car 12volts up to the appropriate voltage to produce higher audio watts. Now of course the amplifier power supply must be able to supply the required current and having more current capacity then you need is always good. But you can't increase an amplifiers power output by simply increasing the current. Voltage is pushed, current is consumed, as required by the load resistance (impedance).
That was painful 😣😂😂😂.... what drives a speaker is current !! For a given impedance this current is proportional to the voltage coming from the amplifier ! Current squared X impedance in Ohms = the power in the voice coil !
As seen in the thumbnail for his earlier TH-cam video, “How can CD transports sound different?,” in the thumbnail for this video, Paul demonstrates the PS Audio salute. As PS Audio advances toward the final victory, we see that the saluting arm has changed from left to right. THIS SIMPLE SALUTE is expected from every customer, and required of each employee.
@@seanjoell LoL not at all! This was typed in humor. I like Paul's videos, own several PS Audio products, and am quite happy with them. Do you know WW2 history? It's the sheer absurdity of the idea of Paul being a fascist that makes the joke. In the other video, another commenter (one who understood the joke) replied that PS Audio was expanding into Poland 🤣
There's actually a lot more to it than just the number and size of drivers. Consider, a large 12" or 15" system like a Cerwin-Vega or an old Klipsch, with a sensitivity of 96dB per Watt at 1 metre will require far less current to deliver a particular sound pressure than you would need to drive a small bookshelf system with an 84dB sensitivity rating to the same output level.
Ah no speakers respond to current, ie voice coil current determines voice magnetic force against magnet force which determines cone travel which determines SPL. For a given voltage, the speaker impedance determines voice coil current and SPL. Amplifier current capability at a given output voltage is another subject.
@@Douglas_Blake I stated impedance and voltage and current ie ohm's law. The fact is speakers are current driven devices not voltage driven devices. Electrostatic and piezo devices are voltage driven devices.
The problem with this question is it's implying a steady state signal. Music is anything but. We do not listen to test tones, the current and voltage will vary with the waveform. Voltage is the signal in a sense and current will follow as required by the speaker and as can be delivered (to varying capability) by the amp. I also think Paul needs to stop trying to dumb down everything, it only serves to leave crucial gaps in the knowledge base. If someone without requisite electrical knowledge (ohms law) doesn't get it, they won't ever get it.
@@davidfromamerica1871 no it was the weekend before the covid bans were lifted and i got there right as they closed. i did have a very insightful conversation with the brilliant Chris Brunhaver.
Yes, the waveform supplied to the speaker is alternating, the current flow continually reverses at the relevant frequencies. The amplitude of the voltage supplied can be represented as an RMS equivalent the same as is done for mains AC voltage, or a peak-to-peak measurement, which is more relevant with respect to, for example, the maximum voltage swing (peak range) an amplifier output can provide prior to going into clipping. Edit: Some amplifiers are designed to be capable of providing a DC output if they receive a DC input (often classed as laboratory amplifiers), but you definitely do not want to supply a DC output to a speaker.
@@PlatypusPerspective You can use a small DC amount for a short time to check the polarity of a speaker or the wiring. Plus pole connected to the red wire and minus to the black or white wire. If the polarity is correct you see the speaker cone moving outwards (in your direction). If not it moves inwards. I sometimes used a 9 Volt battery for that purpose which shouldn't damage the speaker if it's only used for some seconds.
@@Fastvoice Absolutely, at low voltages that's fine and standard practice. The theoretical 10W driving an 8Ω speaker from a 9V battery isn't going to do anything untoward, a potential 300W from a 50V rail in a 100W power amp would be less fun. (Or maybe more fun depending on your point of view...) 🙂
@@PlatypusPerspective Back in the early 1980s, Crown labelled their amps like IC 150a and DC150 and DC300 as laboratory amps. They were designed for professionals I think.They sounded very good when set up properly with the Klipsch La Scalas.
@@artyfhartie2269 I've read that many vinyl LP albums were mastered using cutters driven by DC300 amps. A laboratory amplifier necessarily had characteristics desirable for great sound reproduction - excellent linearity, unconditional stability with reactive loads, no funny business with actually meeting or exceeding specifications, wide frequency response, generous thermal ratings, quality components for long term reliability, etc.
I just avoid the problem of matching an amplifier with (passive) loudspeakers by using actively-powered speakers. In a high-quality active speaker, the manufacturer has matched the internal amplifiers and crossovers to the drivers, so they all perform at their best.
Paul answers like many electrical engineers do... which is not inherently a bad thing but the explanation is overly complex. Paul claims that _volts_ is what drives a speaker. No, though EEs may be trained to think that way. Nearly all loudspeakers, including the ones Paul sells, works by having a current interact with a magnetic field. A cone/dome/planar/ribbon is accelerated, which means the device experiences a force. The force arises as a vector product of the current and the magnetic field. Electrostatic panels, on the other hand, get accelerated (i.e. force) due to a charge interacting with a potential ( _voltage_ ) but very few people own electrostatics. _Watts_ , that is, power, is used to describe and amplifier because the instantaneous energy delivery is what matters, so we want energy/time hence power. The more energy per second an amplifier can deliver the more difficult (mass, stiffness, etc.) a transducer the amplifier can control to produce a given loudness level. Power is not just current (amps) times potential (voltage). It is also force times distance divided by time, if that helps people understand why power is needed to move a transducer (e.g. a cone.) The whole point of describing the impedance of a speaker, e.g. 4 Ohms, is to know how an amplifier will have to interact with the the speaker, that is how much current will be delivered for a given power (and thus loudness) level.
Finally someone who knows the laws of physics! An electrodynamic driver is driven by current. An electrostatic driver is driven by charge. By all means it is in the name. The big question is how did we get here that so many people think it is the voltage or the power? Where did we took the wrong turn?
How is this not more complex than Paul's explanation? Read the comments, there are multiple "experts" here who all say different things, and/or in a different ways and all claim to be correct. Perhaps all of you should come together and freaking decide on a simple explanation, please stop all writing another 300 word essay in a different complex word salad. I thank you on behalf of all music lovers here, without 15 years studying splitting atoms. Sorry, not aimed at you personally, I just want to understand it one time. I thank you for trying, BTW.
@@robinr5787 Ok, let’s try… For an electrodynamic driver: The force on the diaphragm is force factor times the current: F = Bl x I. (Essentially this is all). The force factor you can find in the spec sheet, and is defined in tesla meter or in newton per ampere (!). The force on the diaphragm makes the acceleration (F = m x a). The acceleration (!) makes the sound (SPL, which is not a unit of power). As the impedance of the voice coil is heavily modulated, the voltage is not related to the output. Only indirectly, modulated, distorted and compressed. With some tests it is easy to see that this is the case: if you put a resistor in front of a driver the output is lower, if you raise the voice coil resistance (by heating up the voice coil) the output is also lower (known as power compression). If it was the voltage that drives a driver, the second test would give more output. So, (electrodynamic) speakers react to current (in contrast to what Paul is saying). Let me know if you have more questions.
@@JerryRutten thanks, but I think this is too complex for me. I appreciate your time and help, but I just going to enjoy the music and let the rest be a mystery 🙂.
@@robinr5787 And that’s the whole purpose of audio! And if the industry gets it fundamentals right, you can even enjoy it even more. There are even consultancy firms explaining and showing with simulations to people in the audio industry how drivers actually work.
This is one of those things I need to hear over and over because I have always had a hard time keeping the EE related subject matter retained in my brain housing group. While I have heard these concepts before, the way you explained it saying that you need more current to "sustain" that voltage (and therefore volume) as impedance drops made it click for me. It amazes me that even after your explanation some people think that "high current" doesn't matter or is just a marketing term. While I never got past the entry-level of high-end audio, I learned early on not to waste my time with solid state amps that were not spec'd to increase in power into lower impedances. If I'm buying a 200W amp into 8 ohms, I want to see a 4 ohm rating around 350W or so (also need to make sure they aren't being tricky and giving a continuous rating at 8 ohm but a max rating at 4 ohm to make it seem like you are getting that doubling factor).
Nicely done for trying to translate for the avg person But you skipped some less common aspects of amps.. some have selectable outputs for Voltage or Current drive on the same channel. (Bob Carvers Sunfire design for example)
The actual used amps are a consequence of the voltage supplied and the impedance of the load. The current rating of an amplifier is how many amps it can supply before it distorts/burns out
I guess that means that the power supply of a great audio amplifier is the most important building block of the design. It all comes back to Ohms Law.
Finally--someone gets it!!!! Fact the Power Supply is the Power in Audio Power Amplifier. Also it is the largest and most expensive section of a audio amplifier
Voltage is the forcing function to do the work, just as pressure is what forces the current flow through a garden hose. The amount of flow depends on the obstructions or resistance in that circuit - whether electrical or hydraulic.
That's why amperage is important for bass response that's where the amplifier runs out of juice if it hasn't got enough
It's a bit more than that. SS amps have a reservoir (capacitors) that stores voltage and uses them when big impact sound passages (low end bass response) is created at the speaker. The lower the frequency the speaker needs to produce, the more current is needed from the speaker. Thus more current that is needed from the amplifier. It is all about (what is known as) continuous current (power). Valve (tube) amps do not use capacitors the same way (mostly) as a SS amp. This is one of the reasons that tube amps are more expensive. Tubes generate very high voltages (far more than SS amps) and have a continuous power level that can maintain better current draw demands. However, SS amps have higher combined total watts output than tube amps. Both have high values for continuous power to the speaker (although the topology between the amps are different).
Apologies not accepted... At 6:51, your presentation was direct, to the point, and very informative... Much appreciated - Have a nice summer...!!!
Thank you Paul now I know what the AC/DC song High Voltage Rock n Roll is about😜
Infinity 9 Kappa - I learned the hard way when purchasing these speakers which dipped to a minimum .5 ohm and then sat on average under 3 ohms. Add to that their 84 dB sensitivity and my current 200 'watts' per channel amplifier shutdown on me daily 😢. So yeah, 'watts' mean shit! You must know your speakers 'real' in-use resistance (ohms), as well as their actual sensitivity, as well as your desired listening levels.
It depends on the speaker load. Voltage drives volume. Current is demanded by the consumer (speaker).
Very clear explanation, Paul.
Thank you.
Paul, a whiteboard would make your content more substantial
That would be to service those persons of a visual learning discipline. I thought he very clearly articulated a relatively complex concept, but as an engineer it’s something I was already acutely aware of and I’m personally not visually inclined in my learning methodology.
I think the whiteboard would certainly service some persons but I also think his delivery on these videos is very informal and focused on entertainment as much as education. If he were to draw it out on whiteboard, I could see a certain sector criticising for being condescending or pedantic. Sometimes on social media, you just can’t win. Paul’s deliver on these videos is genuine and faithful to his personality. For those that want to delve deeper into the electronics and theoretical sciences, I’d suggest reading an engineering textbook on subject
He’s done this video on a whiteboard a couple times.
Love the explanation. Looking forward to your next watt, amp, and voltage example video.
It's an interesting topic with no end to the complication that can result. Most loudspeaker manufacturers give their speakers a "nominal" impedance rating, as the impedance changes by frequency. We tend to think about Ohm's law, but that technically applies only to resistance. With a speaker, you're also dealing with capacitance and inductance. Music is generally a complex mix of frequencies, which means that the amplifier is looking at different impedance for each frequency.
As far as "high current capacity" in an amplifier, it's not just the overall power capacity of the power supply, but its ability to deliver that power across the load, which may be limited by internal components. Amplifiers with high current capacity are linear over a wider range of impedance in their ability to deliver power to the load.
Love your explanation. Ohms & Watts law basics but you explain it so elequantly as it pertains to audio. Love it Paul.
The point is that current is voltage dependent not the other way round for given load , if you want to increase the current through a fixed load, you have to increase the voltage applied to it, you cannot create a circuit with fixed voltage with a fixed load and have a current control knob, electricity doesn't work like that.
it is more complicated than that because analogue sound signals in a wire are AC and speaker loads are frequency dependent which is probably why high current AMP marketing term came in, but its smoke and mirrors if you want to increase the AC current through a load its the peak to peak AC voltage that had to increase.
Thank you Paul, this was the most technicaly informitive and therefore most useful video that I've seen from you to date. Keep up the good work!
It turns out, I was looking at impedance kind of backward. I think. I thought a lower ohm speaker meant that it was easier to have higher voltage, hense the higher wattage rating from the amplifier and should play louder as a result of that increased wattage capability. But now I'm a little confused about which of these statements is true or false.. And why many people feel that lower ohms are better for higher performance, if it actually takes more amperes instead of less, to maintain the same voltage?
I know when you first hear it, it doesn't make sense, but its true. The lower the resistance, the harder the amp has to work. Its kind of like water pressure. Think of a standard 1 inch garden hose. Imagine the water pressure at your home is represented by volts, and the diameter of the hose is represented by amps. When you turn the hose on all the way, water usually shoots out 2 or 3 feet. If you need the water to go farther, you can put your thumb over the end of it, and increase resistance. You'll have less water coming out of the hose but it goes much farther. Now imagine getting some type of adapter that lets you attach a big 3 or 4 inch fire hose to your house. When you turn it on all the way, water won't shoot out at all. It may take a few minutes just to fill the hose up. You only have so much water pressure, and its not enough to overcome the drop in resistance. So, if you need to water your garden 20ft from the hose, your thumb is good enough. If you have to put out a fire, you need a bigger hose and a fire hydrant.
Its not a perfect example, but its enough to get the basic idea.
@@AT-wl9yq This is a good explanation! But then, if lower impedance speakers are actually harder to drive, why do people feel they are better? Also, coming from higher end headphones, the high impedance cans definitely need more power to drive, VS the 'low' impedance, 32 ohm stuff for portable use. Good luck running my LCD-4 off a cell phone and they don't have outrageously low sensitivity, if I remember correctly. But 200 ohms and love power.
@@zackw4941 Your first question is easy to answer. They don't have a complete understanding of all the relevant factors, and they make judgments based on only what they think, or know. Your point makes sense. Its a counter intuitive concept, but once you understand all the variables, it all makes sense.
As for your headphone question, I'm not an expert. I don't know headphones like I do regular audio. If I had to guess, the difference has to do with the application. Headphones are small speakers and work basically the same way. The big difference is in the environment. In a home audio setup, you sit about 8 to 10 feet away from the speakers. The speakers also have to energize the room you're in. The amount of air that the speakers in a home system has to move is thousands of times greater than what is required of headphones. Removing that major variable from headphones, it would make sense that others become more important. But that's my best guess. And my guesses are not always correct.
@@AT-wl9yq The major 4 ohm proponent I'm thinking of is Eric Alexander of Tekton Designs. He likens 4 ohm to a higher flowing head on an engine. He of all people should know what he's talking about. But either way, it seems that sub 8 ohm speakers have become basically the norm now, so their must be a reason they are favorable.
Headphones are nice because you don't have to deal with a room and you can listen whenever you want. My LCD-4 setup is pretty speaker like, but there's still no substitute for cranking up a big pair of speakers when no one is around.
@@zackw4941 I've heard the argument you make in your post quite often in recent years. In my last post, I said this.
"Your first question is easy to answer. They don't have a complete understanding of all the relevant factors, and they make judgments based on only what they think, or know."
I'm going prove it to you right now. Never assume or guess. It will only get you into trouble.
"He likens 4 ohm to a higher flowing head on an engine. He of all people should know what he's talking about. But either way, it seems that sub 8 ohm speakers have become basically the norm now, so their must be a reason they are favorable."
Out of curiosity, I watched the Tekton video, along with a few others, and couldn't believe what I was seeing. Its no wonder why so many people have trouble with this.
To start, when you buy a speaker, its not 4 ohms or 8 ohms. Those are averages. As you are playing music, the speakers resistance is constantly changing. It never just sits at 4 or 8 ohms. The amount of resistance an amp sees is bases on the frequency its asked to reproduce. Out of the entire range of frequencies a speaker is capable of playing, there is only one frequency where the speaker will provide a 4 or 8 ohm load to the amp. Think of a piano. Every key on the piano, when played, will show a different amount of resistance to the amp. The lower the note, the lower the resistance. Higher notes equals higher resistance.
When looking at the specs for a pair of speakers, there are 2 things you need to see. The first is the average that I mentioned above (4 or 8 ohms). You should also see another number, and its more important than the average. Its the lowest amount of resistance the speaker is capable of showing the amp. For example, if you are comparing 2 pairs of speakers and one is rated at 8 ohms with a 4 ohm minimum, and the other speaker is rated at 8 ohms with a 3 ohm minimum, the speaker that drops down to 3 ohms is a much harder speaker to drive. Both are listed as 8 ohm speakers. For anyone to not include this information in a talk on amps and speakers is nothing short of criminal.
I'm going to make a recommendation. From what I understand of youtube, including links to other web sites is not permitted, so I'll list where you need to go. Start by going to Vandersteen speakers website. Its vandersteen dot com. Then click on the resources tab. Look for something that says memorial page or Audio Perfectionist Journal (APJ). This will take you to links where you can actually download all the journals for free.
The story behind APJ was someone wanted to start a new audio publication that provided information and reviews that didn't take money for advertising. He brought in one of the reviewers for The Absolute Sound to help out. Not long after that, the guy died unexpectedly. His family agreed to make all 15 or so issues of the journal free for anyone who wants to read them. I'm recommending this as a reference because its the best resource I've ever seen on high end audio. It would take the average person years to accumulate all the information he gives you. And its free. Everything we're talking about here, and far more, will delt with by someone who is much better at explaining things better than I can. If you are interested, its well worth your time.
Paul McGowan, you decreased the level of ignorance on this planet with a significant rate!
Thank you, for all your videos! They are a great learning curve for all audiophiles.
Very helpful. Explanation. Just one thing: Using ‘Amps’ for both Amperes and Amplifiers is slightly confusing.
The penny dropped particularly at 5:30, Great explanation.
Power = Voltage x Current. Current = Voltage / Impedance. Power = Voltage x Voltage / Impedance. Twice the voltage means 4 times the power in the same speaker impedance. Power is energy per time (1 Watt is 1 Joule per second) and the speaker cone effort of moving the air is ultimately about work.
Very correct! Amps is an outdated term still used today. Remember, the signal (analog voltage) is the voltage language the speaker interprets. The voltage current levels/impedance effect amplitude on the sound reproduction at the speaker (the work being done to reproduce the sound from the speaker drivers).
@@jayedgar2373 No power no sound. The 1st law of thermodynamics rules ultimately. When a power plant outputs 1 Joule of energy per second (1 Watt) it experiences losses through the path from the power plant generator to your speaker cone moving the air but ultimately some fraction of that 1Joule per second is what moves the air as energy per time. Most of the energy gets lost as heat...but the SPL you hear is all about Joules of work following the 1st law of thermodynamics. So power is what really matters when you want to move air molecules...
@@ThinkingBetter Where did I ever say "no power" or dispute the 1st law of thermodynamics? The signal path (from the front end through a preamp through to the amp) is known as the signal path. The pushing of the signal path is gained in output transformers (small, but able to produce on average 1.7v or 1.7 joule per coulomb = equation for impedance + input sensitivity) to the amplifier. The preamplifier to the amp requires anywhere from 0.5 to 2 volts (generally, but based on the preamp) input (to the amp) based on amplifier nominal impedance (sensitivity). The amplifier increases the voltage (output) to the speaker (measured through the amps input voltage). The amplification of that input signal is what the amp does. The voltage signal is very low into the amp actually. But to overcome (as you put it) impedance (connectivity, cable, speaker/input sensitivity and the electron field lines as they travel through the speaker cable), does require an amount of voltage to overcome any resistance in that circuit. The voltage required to overcome this resistance is rather small (but many things in the path can increase impedance). As Paul put it "the ohms rating on a speaker is not static". Neither is resistance/impedance. But the voltage to "push" that signal path at low volumes is rather quite small. The impedance at the speaker is based on how efficient the speaker is. A 90+db speaker is so little impedance, that it is measured in Mv (millivolts). In other words, that 90db speaker does a LOT with small amounts of voltage (highly efficient) to drive (work as you put it). However, 82 to 84db speakers require more power (primarily due to the woofers reaching lower extensions in frequency) to do the work as again you put it. They also have higher impedance (generally) in the hundredths of volts (generally). Speakers vary so much, that you can't put a label on any specific voltage required for the speaker to produce sound. Each speaker is rated (voltage requirements) to produces sound (minimum and maximum).
@@jayedgar2373 I didn’t say I disagree with you but just made the point that power is what makes a speaker cone move air. It’s like some people think torque is what accelerates a car. Power is what accelerates a car.
Wonderful explanation! 🎉
Thanks, Paolo
I finally understand! Thanks Paul
I really appreciate you sharing your wealth of knowledge with us, this was a very helpful explanation, most appreciated.
This was a good one. Though I wonder about the term watts in this context. I know the Ohms law and those things, but the signal has such a big variation so i wonder how it can be measured.
@Douglas Blake Yep. Each speaker interprets the voltages differently (crossover). So, pick a speaker and find out what the speaker is rated at. Just my 2 cents.
Paul ITS the current that drives magna pens when you have a high-powered high current amplifier is that correct current it should be a concern with the inefficient speaker like magna pans and 84 DB
Good explanation Paul, thank you.
You cleared that up for me - Thanks Paul
I noticed the review mirror you have attached to your monitor. Keeps a view of your six & prevents the staff from sneaking up on you ! 😅
OMFG I need one of these now!
Volts is the pressure that causes charge movement. Amps is rate of flow of charge. Thus higher voltage is required to increase flow of current which will increase the wattage.
Voltage does not go into a speaker. Voltage is measure of potential difference between two points. Voltage is measured across the speaker, while current flows through speaker. A speaker has a rated impedance to current flow, measured in ohms (but actually a bit more complex than that, but a low frequency it can be considered mainly resistance). For given impedance (all things being equal), the higher the voltage across it the higher the current flow through it & higher the energy dissipated by it. The higher the voltage, the higher the current for given ohm rated speaker, & therefore the higher the watts (power) expended. It is the current flow through the speaker that determines the intensity of sound from the speaker, but to get that higher current you need to increase the voltage (V RMS value as audio is a AC composite wave) applied to speaker. Hence the amplifier is both amplifying audio signal presented to it (within voltage range before clipping distortion) while delivering sufficient current to drive the speaker without melting the high current output power transistors.
Great post but I am still confused about this (all my life). Volt, ampere and resistance are abstract concepts.
As far as I know electricity is a movement of electrons. It would be nice if Paul could explain what actually happens physically with those electrons in a cable. Do more electrons pass through a cable at higher voltages? Is the movement greater at higher amps? etc etc. I have no clue, but would like to understand what is physically happening.
The electrons do not move like water through a hose. An audio signal is AC, the electrons move back and forth, moving very little. One electron shoves another, that electron shoves the next one, and so on. Higher voltages makes the electrons shove harder.
Very clear explanation, Thank you. I do enjoy your video's Paul.
great explanation
Very well explained, thank you.
To put it into English, maximum power will be achieved when the speaker impedance matches the output impedance of the amplifier. An amplifier is capable of providing a certain voltage and a certain current. Maximum power is achieved when it does both at the same time. If the speaker impedance is less than that of the amplifier, then you’ll hit the maximum output current before maximum voltage is achieved. If the speaker impedance is higher than the amp, then max voltage will occur before max current is reached. An 8W amplifier designed for 8 ohms would produce 8V at 1A into an 8 ohm speaker. 8Vx1A=8W. If you use a 4 ohm speaker, the maximum current of 1A will happen at 4V. 4Vx1A=4W. With a 16 ohm speaker at the maximum voltage of 8V will pull 0.5A. 8x0.5A=4W.
There is a problem with your explanation, in that the output impedance of an amplifier is very low in comparison to the speaker load, and it isn't what determines the safe available current to the load. It's not the amplifier's output impedance that the speaker needs to match, it's the output voltage and current capacity, as you explain, but that is not a function of the amplifier's output impedance.
@@PlatypusPerspective There are two things to amplifier impedance. If a small signal impedance meter is connected across the amplifier output terminals, it will indeed read very low as the output impedance is artificially lowered by the application of negative feedback in order to provide damping amongst other things. However, this only holds true within the capabilities of the output transistors and makes no difference to the the amount of current they can ultimately source or sink and therefore the ‘real’ output impedance, which is the only thing of relevance here. If a 200W amplifier designed for an 8 ohm speaker really had an open loop output impedance of 0.01 ohms, the output devices would have to be able to handle 4000 amps and the power supply would need to be capable of 160KW assuming 100% efficiency. You also mention that it’s not the impedance that matters, but matching voltage and current. Ummm, Impedance = Voltage / current and power = voltage x current therefore you’re contradicting yourself. A speaker of equal power rating and impedance to the output of the amplifier will be matched in terms of voltage and current.
@@petesmith2234 The issue seems to be in application of terminology - in all my years of maintaining, designing and building audio equipment I have never known of anybody taking the output impedance of an amplifier to mean anything other than the small signal source impedance. When you said output impedance in your first sentence, evidently you were meaning rated load impedance.
@@PlatypusPerspective small signal impedance is irrelevant when I comes to an amplifier’s ability to deliver power. Small signal impedance is measured as the amplifier’s ability to resist a small signal generator trying to wiggle the output terminals up and down. It’s relevant in terms of damping, but that’s it. Power will always equal volts times amps give or take power factor, and maximum power transfer will always be when available volts x volts / amps equal load impedance. It has nothing to do with small signal impedance.
That was very helpful. So would the resistance rating of a speaker be analogous to the bore diameter of a trumpet and the voltage would be analogous to the PSI generated by the horn player who is somewhat analogous to an amplifier's transformer and ability for capacitance and recharging the caps? Except the resistance of a speaker is in flux where as with a trumpet relatively speaking there are no significant changes to the bore size increasing or decreasing resistance? I had to play along with the long winded analogy 😅 🎺
Even going further, the higher the resistance of the speaker, the more inertia has to be overcome giving you a harder hitting speaker but at lower volumes/energy levels will result in subdued dynamics. The opposite for low resistance speakers being more responsive but also requiring more energy pressure to get authoritative sound pressure. I have a small bore horn that is challenging for me to play softly but my larger bore I have more control over the dynamics
@Douglas Blake so verbose you are in your engagement makes you extremely credible 😂
No need to apologise Paul some explanations are more complex and take longer than others.
You're the man!
But we do not listen to sine wave test tone sweeps and speakers aren't purely resistive loads. That is how amplifiers are tested though. When playing real music through speakers, they perform quite differently in respect to power. And remember, bass frequencies from say 200 hz down take the vast majority of power. That's where high current comes in. (Think orchestral strikes) ALL speakers are not the same either. You have conventional drivers, electrostatics, planar magnetic s, horns. Each of those presents a very different load to the amplifier.Also, as the speaker plays, the woofer wants to go higher in impedance and the tweeter lower. It's not 100 watts is 100 watts is 100 watts. If that were true, all AVR's would have lots of bass slam, power and volume at their "600 watts output". I've yet to hear one that does. Some 100 watt amps have dual power supplies, massive filter capacitors, output transistors while others have one power supply, small filter caps and IC outputs. They are rated the same 100 watts though.One may have 2 db of dynamic headroom while the other has .5 db. I love how Paul try's to simply things, but often the answers are quite complex.
I think the high current thing is marketing flim flam, its voltage that you need, current is consequential
Hmm...So the sensitivity of a speaker depends on it voltage?
Sensitivity of a speaker is independent of the amplifier --- it is a physical attribute of the overall speaker itself.
It depends on the type of crossover used, the construction of the drivers and the design of the cabinet enclosure. Once you start applying voltage to it it will produce sound at some loudness level (dB) and that will also depend on the type of voltage, particularly AC voltage and what frequencies you are transmitting. That's why some speakers do not produce much sound below a certain Hz. You've no doubt seen some speaker specs that give a -3dB output of say 40 Hz; it just has lower efficiency (sound output) at that tone.
The loudness of a speaker however will depend on how much voltage is applied in concert with the speaker's sensitivity.
Very well explained
Easy: If all else is equal (which of course it can't actually be),
favour an amplifier that can deliver more current.
Ignore watt output and look at the actual power supply and that together with what class amp it is will tell you how powerful it actually is into the desired load.
I.e a class AB amp that gives 2x 150w into 8ohms would require about 1000 watts to deliver 2x 300 watts into 4ohm.
And to get 2x 600w into 2ohms it would need over 2000w power supply.. Class D is more efficient but for class AB this is true since they are about 50-60% efficient.
Here's a post from another PS video, relevant here too.
It's all about the voltage, not the current! A "high current amplifier" is just a marketing ploy.
You have a fixed load impedance, lets use 8 ohms. So for 200 watts we need an audio signal at 40 volts.
((40volts * 40volts) / 8ohms)= 200watts. And then we divide (200watts / 40volts)= 5amps of audio current.
We have no control of the current. That is determined by Ohm's law. Let's do 406 watts
((57volts * 57volts) / 8ohms) = 406watts. Then (406watts / 57volts)= 7.1 amps. The current is what it is.
To output more power you must supply more voltage to the speaker. If your amp can only produce 40volts of audio to the 8 ohm speaker, it doesn't matter if the power supply can produce 10amps, 100amps. You still only get 200watts at 8ohms.
This is why basic car stereos can only produce about 3 watts yet the car battery can supply several hundred amps. The next step in car stereo was bridging. Here you are doubling the audio voltage produced. Today we use a switch mode power supply to get the car 12volts up to the appropriate voltage to produce higher audio watts. Now of course the amplifier power supply must be able to supply the required current and having more current capacity then you need is always good. But you can't increase an amplifiers power output by simply increasing the current. Voltage is pushed, current is consumed, as required by the load resistance (impedance).
That was painful 😣😂😂😂.... what drives a speaker is current !! For a given impedance this current is proportional to the voltage coming from the amplifier ! Current squared X impedance in Ohms = the power in the voice coil !
We do *not,* in fact, say "missuruh" in Missouri.
As seen in the thumbnail for his earlier TH-cam video, “How can CD transports sound different?,” in the thumbnail for this video, Paul demonstrates the PS Audio salute. As PS Audio advances toward the final victory, we see that the saluting arm has changed from left to right.
THIS SIMPLE SALUTE is expected from every customer, and required of each employee.
Is this a disgruntled ex-employee?
@@seanjoell LoL not at all! This was typed in humor. I like Paul's videos, own several PS Audio products, and am quite happy with them. Do you know WW2 history? It's the sheer absurdity of the idea of Paul being a fascist that makes the joke. In the other video, another commenter (one who understood the joke) replied that PS Audio was expanding into Poland 🤣
An AMPlifier AMPlifies AMPeres.
Current is required to move the magnet motors in the speaker. The more drivers and the larger the drivers are...the more CURRENT is required.
There's actually a lot more to it than just the number and size of drivers. Consider, a large 12" or 15" system like a Cerwin-Vega or an old Klipsch, with a sensitivity of 96dB per Watt at 1 metre will require far less current to deliver a particular sound pressure than you would need to drive a small bookshelf system with an 84dB sensitivity rating to the same output level.
Ah no speakers respond to current, ie voice coil current determines voice magnetic force against magnet force which determines cone travel which determines SPL. For a given voltage, the speaker impedance determines voice coil current and SPL. Amplifier current capability at a given output voltage is another subject.
@@Douglas_Blake I stated impedance and voltage and current ie ohm's law. The fact is speakers are current driven devices not voltage driven devices. Electrostatic and piezo devices are voltage driven devices.
The problem with this question is it's implying a steady state signal. Music is anything but. We do not listen to test tones, the current and voltage will vary with the waveform. Voltage is the signal in a sense and current will follow as required by the speaker and as can be delivered (to varying capability) by the amp. I also think Paul needs to stop trying to dumb down everything, it only serves to leave crucial gaps in the knowledge base. If someone without requisite electrical knowledge (ohms law) doesn't get it, they won't ever get it.
That's about as simple as you can get without getting into any real math or theory, while being as concise as possible.
It's so difficult to make something straightforward more simple.
Yup and those kind of amps that can steadily swing and make your soul quiver are not cheap🍻
Not familiar with the term listener, not a microphone ?
i still have the pinecone i got from your parking lot
Did Paul autograph it for you.🤔
@@davidfromamerica1871 no it was the weekend before the covid bans were lifted and i got there right as they closed. i did have a very insightful conversation with the brilliant Chris Brunhaver.
I take it it is AC voltage and not DC
Yes, the waveform supplied to the speaker is alternating, the current flow continually reverses at the relevant frequencies. The amplitude of the voltage supplied can be represented as an RMS equivalent the same as is done for mains AC voltage, or a peak-to-peak measurement, which is more relevant with respect to, for example, the maximum voltage swing (peak range) an amplifier output can provide prior to going into clipping. Edit: Some amplifiers are designed to be capable of providing a DC output if they receive a DC input (often classed as laboratory amplifiers), but you definitely do not want to supply a DC output to a speaker.
@@PlatypusPerspective You can use a small DC amount for a short time to check the polarity of a speaker or the wiring. Plus pole connected to the red wire and minus to the black or white wire. If the polarity is correct you see the speaker cone moving outwards (in your direction). If not it moves inwards. I sometimes used a 9 Volt battery for that purpose which shouldn't damage the speaker if it's only used for some seconds.
@@Fastvoice Absolutely, at low voltages that's fine and standard practice. The theoretical 10W driving an 8Ω speaker from a 9V battery isn't going to do anything untoward, a potential 300W from a 50V rail in a 100W power amp would be less fun. (Or maybe more fun depending on your point of view...) 🙂
@@PlatypusPerspective Back in the early 1980s, Crown labelled their amps like IC 150a and DC150 and DC300 as laboratory amps. They were designed for professionals I think.They sounded very good when set up properly with the Klipsch La Scalas.
@@artyfhartie2269 I've read that many vinyl LP albums were mastered using cutters driven by DC300 amps. A laboratory amplifier necessarily had characteristics desirable for great sound reproduction - excellent linearity, unconditional stability with reactive loads, no funny business with actually meeting or exceeding specifications, wide frequency response, generous thermal ratings, quality components for long term reliability, etc.
I just avoid the problem of matching an amplifier with (passive) loudspeakers by using actively-powered speakers. In a high-quality active speaker, the manufacturer has matched the internal amplifiers and crossovers to the drivers, so they all perform at their best.
Paul answers like many electrical engineers do... which is not inherently a bad thing but the explanation is overly complex. Paul claims that _volts_ is what drives a speaker. No, though EEs may be trained to think that way. Nearly all loudspeakers, including the ones Paul sells, works by having a current interact with a magnetic field. A cone/dome/planar/ribbon is accelerated, which means the device experiences a force. The force arises as a vector product of the current and the magnetic field. Electrostatic panels, on the other hand, get accelerated (i.e. force) due to a charge interacting with a potential ( _voltage_ ) but very few people own electrostatics.
_Watts_ , that is, power, is used to describe and amplifier because the instantaneous energy delivery is what matters, so we want energy/time hence power. The more energy per second an amplifier can deliver the more difficult (mass, stiffness, etc.) a transducer the amplifier can control to produce a given loudness level.
Power is not just current (amps) times potential (voltage). It is also force times distance divided by time, if that helps people understand why power is needed to move a transducer (e.g. a cone.)
The whole point of describing the impedance of a speaker, e.g. 4 Ohms, is to know how an amplifier will have to interact with the the speaker, that is how much current will be delivered for a given power (and thus loudness) level.
Finally someone who knows the laws of physics!
An electrodynamic driver is driven by current. An electrostatic driver is driven by charge. By all means it is in the name.
The big question is how did we get here that so many people think it is the voltage or the power? Where did we took the wrong turn?
How is this not more complex than Paul's explanation? Read the comments, there are multiple "experts" here who all say different things, and/or in a different ways and all claim to be correct. Perhaps all of you should come together and freaking decide on a simple explanation, please stop all writing another 300 word essay in a different complex word salad. I thank you on behalf of all music lovers here, without 15 years studying splitting atoms.
Sorry, not aimed at you personally, I just want to understand it one time. I thank you for trying, BTW.
@@robinr5787 Ok, let’s try…
For an electrodynamic driver:
The force on the diaphragm is force factor times the current: F = Bl x I. (Essentially this is all).
The force factor you can find in the spec sheet, and is defined in tesla meter or in newton per ampere (!).
The force on the diaphragm makes the acceleration (F = m x a). The acceleration (!) makes the sound (SPL, which is not a unit of power).
As the impedance of the voice coil is heavily modulated, the voltage is not related to the output. Only indirectly, modulated, distorted and compressed.
With some tests it is easy to see that this is the case: if you put a resistor in front of a driver the output is lower, if you raise the voice coil resistance (by heating up the voice coil) the output is also lower (known as power compression). If it was the voltage that drives a driver, the second test would give more output.
So, (electrodynamic) speakers react to current (in contrast to what Paul is saying).
Let me know if you have more questions.
@@JerryRutten thanks, but I think this is too complex for me. I appreciate your time and help, but I just going to enjoy the music and let the rest be a mystery 🙂.
@@robinr5787 And that’s the whole purpose of audio!
And if the industry gets it fundamentals right, you can even enjoy it even more. There are even consultancy firms explaining and showing with simulations to people in the audio industry how drivers actually work.
I would not want to watch all the people in the comments on a video chat platform.
It would be like the Nursing Home meets the Asylum.
IVE BEEN ROBBED!!! ... a 7 min video with no _tangent!_
I don’t know if I understand all that. 😊 I buy my audio equipment from Walmart.😎
Apparently Walmart knows.😀👍😎🤗
U = I x R
This is one of those things I need to hear over and over because I have always had a hard time keeping the EE related subject matter retained in my brain housing group. While I have heard these concepts before, the way you explained it saying that you need more current to "sustain" that voltage (and therefore volume) as impedance drops made it click for me. It amazes me that even after your explanation some people think that "high current" doesn't matter or is just a marketing term. While I never got past the entry-level of high-end audio, I learned early on not to waste my time with solid state amps that were not spec'd to increase in power into lower impedances. If I'm buying a 200W amp into 8 ohms, I want to see a 4 ohm rating around 350W or so (also need to make sure they aren't being tricky and giving a continuous rating at 8 ohm but a max rating at 4 ohm to make it seem like you are getting that doubling factor).
Nicely done for trying to translate for the avg person
But you skipped some less common aspects of amps.. some have selectable outputs for Voltage or Current drive on the same channel.
(Bob Carvers Sunfire design for example)