Got it wrong. Please delete and redo. It is power not straight voltage that determines the loudness. Or voltage squared by impedance. That is why speaker sensitivity is usually quoted in dB/W which is impedance independent.
Agree, Paul makes excellent videos and we can occasionally have some gray zones of arguments but this video is a total bummer of misinformation. It appears to me that in the USA a lot of people don’t know what power is. In automotive discussions, people here are equally mixing power and torque and those explaining it often try to use false non-scientific equivalents that can’t yield a genuine understanding.
Say you have 2 identical speakers, one wound for 8 ohms, other wound for 4 ohms. You take an amplifer and drive 10 volts say @ at 1Khz into the 8 ohm speaker, it will consume 12.5 watts. Do the same thing to the 4 ohm speaker, and it will consume 25 watts, providing the amp maintains 10 volts. The 4 ohm driver "should" play about 3db louder than the 8 ohm unit? A solid state (dated I know) amp is a current producing device more that a voltage producer. You get into the car audio world, and you never see speakers with over 4 ohm ratings. For subs, you can get down to 1 ohm! Why? Because mobile amps are made for massive current outputs not high voltage. Please flame me if I'm way off my rocker!
Yes, Paul is not right. You gain 3dB going for half the impedance if the amplifier can maintain the voltage and your speaker has the same efficiency. Power is what drives the speaker driver. The speaker does work and work per time is power measured in Watts.
Jim Mitchell Paul is great and PS audio makes great products for sure. Reality is that in some cases an 8 Ohms speaker is more energy efficient than a 4 Ohms speaker and in such cases Paul can still be right 😊
@@ThinkingBetter No, Paul can't be right... because what he said is wrong. Providing the output amplitude stays the same, the 4 ohm load draws double the 8 ohm. The load(in this case a speaker) determines the amount of power drawn from the source(amp). Assuming we have proper controls in our little experiment, we should see a 3 db increase in sound level. You may want to bring other variables like speaker efficiency, stiffness of the amp's output, etc, etc, ad nauseum into the discussion. That's why I said we need to have controls in place, otherwise we're comparing apples and oranges and the whole exercise becomes irrelevant. Have a good day.
mikeduino I’m trying to be nice to Paul. Of course half the impedance will mean 3dB SPL increase at the same output voltage of an amp assuming the energy efficiency is the same. Yes Paul is super wrong on his point. I suspect he believes voltage translates to SPL. See my comment elsewhere about why it’s power (energy by time) that determines the SPL.
I’m way more confused now. My knowledge is that: Same amplifier same speaker pair Speaker A is 8 ohms Speaker B is 4 ohms Amplifier will push 100 watts into Speaker A 200 watts into Speaker B Speaker B will be 3db louder Volts will be the same Resistance changes Current goes up. Watts go up.
Two identical speaker with one having half the impedance will have the one with the low impedance playing 3dB louder than the one with the higher impedance if you don’t touch the volume knob and the amp can double the power. In cars some use 1 Ohm speakers to get the max SPL out of the amps.
I think it also needed to be said that if you have a 10 watt amp and want to double the volume of sound, then you need 10 times the power to achieve that, provided the Speakers are the same in each senario.
The best analogy I suppose you could say the volume knob is like the throttle on your car doesn't matter how powerful the engine you can all go at the same speed
John sweda No, this video is not correct. The volume (sound pressure level) is a function of the power (energy by time) and not the voltage itself. The speaker will play 3dB louder when the power is doubled. Thus if you use a 4 Ohm speaker identical to another 8 Ohm speaker (same drivers with same efficiency), you will gain 3dB in sound pressure level (actual volume). Car speakers exist down to 1 Ohms to gain higher sound level using this method. This can mean 9 dB louder at 1 Ohms than 8 Ohms as you cut the impedance 3 times each giving you 3dB assuming the amp can handle it.
So if it takes 200 volts to push the same current across twice the impedance, you get twice the power. Right? Where did that power go in the universe if it didnt make sound power?
I like you Paul you come across as a great guy, but nearly every ask Paul I watch leaves me thinking What,, you seem to get three quarters of the way through explaining something then change your line of thinking/ explanation and try a different approach, ? this happens all the time, well alott anyway,, not nitpicking, its just how the explanations leave me feeling.
It is a pure function of the current flowing in the speaker wire, through the voice coil of the speaker and back to ground via the amp. Voltage is pressure. Amps is the amount of outer valence electrons in the copper speaker wire being exchanged over time - the flow of electrons. P= I x E where P is power or watts and I is amps and E is voltage. E=I x R. R is either 4 Or 8 ohms. Paul wants the output voltage to stay the same. So the amp must be capable of supplying the current as the ohms demand. Simple?
This one makes perfect sense to me but I do what you’re doing all the time so it seems some of those comment may have little or no knowledge of basic electronics. Yet I can not think of a way to put it in either laymen’s terms or audio file terminology.
I've hooked typical 6x9 car speakers in a garage to an old receiver (my 1st receiver, Kenwood KR-3090, indoors). Am I straining this receiver? I ask, because it is frying out again, and have disconneted it. Should I use resistors in series?
If your amp doubles power into 4 ohms where did that extra power go. Previously you said you cant destroy energy which is power multiplied by time. So where did that extra VA go if it didn't make sound energy?
Does that mean that 4 ohm speakers in general is about 3dB less than 8 ohm speakers? So you will get 2watt on a 8 ohm speaker is same volume as 4watt into 4 ohm?
I'm pretty sure Paul's explanation is incorrect. The implied assumption is that you're comparing a 4-ohm speaker and an 8-ohm speaker, where both of them have the same efficiency in terms of dB per watt. In that case, when you switch from the 8-ohm to the 4-ohm speaker, the voltage will stay the same, but the current will double. Hence the wattage fed into the speaker will double, and the volume will increase by 3 dB.
Of course, the big assumption is the same efficiency of the two different speakers. Speaker efficiencies can easily vary by more than 3 dB, and that could easily swamp out the result if it's not a well-controlled comparison.
@@kc9scott Given same efficiency speakers eg. 89 dB / w at 1 meter distance. If an 8 ohm and 4 ohm speaker have the same efficiency, the 4 ohm speaker will be louder for same voltage.
Paul, you missed out on the sensitivity rating. Sensitivity makes a far greater difference. I have had speakers as much as 18 Db difference, both 4 ohm and with the same amplifier power to each, you couldn't even hear the lower sensitivity ones.
Paul, this video is so wrong and you should redo it. You can look at it this way. Like a human body, we consume energy to do work much like a speaker consume energy to move air molecules (sound). You become fatter when you consume more energy per time (e.g. measured in joules per day). Same way your speaker plays louder when it gets more joules per second. Voltage is not making work happen in itself. Wattage (power) is the real deal. 1 joule per second from your amp to your speaker is equal to 1 Watt. When your speaker is half the impedance, you will give it twice as many joules per second to do work for. This translates into 3dB of sound pressure level increase. In automotive audio, you can find 1 Ohm speakers to gain 9dB SPL against 8 Ohm speakers since you cut the impedance in half 3 times to get from 8 Ohms to 1 Ohm (9 = 3 x 3). Also, you can easily imagine if a speaker went the other way, like headphones, towards much higher impedance, you would get much lower power to your speakers unable to provide the joules of energy to move a heavy voice coil. For example, a 256 Ohm speaker would play 15 dB (5 x 3) lower volume than an 8 Ohm speaker using the same amp as you doubled the impedance 5 times.
subwoofers with lower impedance like 2 ohm or 1 ohm tend to have more SPL, louder by 1db or as much as 3db difference at 30hz, I tested it in a subwoofer simulator, and also the speaker manual graphs showed the same correlation between ohms and output/loudness, the 2ohm had more bass than the 4ohm at 30hz, it has nothing to do with how much power it draws, lower ohm speakers are simply better for deep bass, anything below 40hz...... and 4ohm 8ohms 16 ohms, the higher the ohms the better the mid bass youll get, so lower ohms better for deep bass and higher ohms for mid bass drivers, so yes it does make a difference to loudness depending on if it's a mid bass driver or a deep bass driver.
I believe you kind of have it backwards. The increased loudness of low ohm drivers for low frequencies isn’t a result of the coils impedance. Rather the lower energy density of low frequency waves at the same amplitude make it easier to drive low impedance speakers compared to high impedance ones.
Don't forget loudspeaker sensitivity :) different speakers have very different sensitivities, from 80dB to late 90ish.... So take a 4ohm pair and an 8ohm pair at different sensitivities and they'll sound very different volume level wise :)
The sensitivity of a speaker is a real issue. For every 6db increase of sensitivity, you can realize double the volume of sound. The highest I've seen in sensitivity is 103db, 1 watt - 1 meter. A 2o watt amp such as a Fender Deluxe Reverb with a 103db speaker can have volume levels like a 50 watt amp. But remember, you need 10 times the power output to make twice the volume on an amp with the same speaker configuration.
6:50 Okay, but, in the majority, you can lose weight if you eat a lot of certain junk food like that. But, in the majority LOL, you will experience gaining thigh size because lately so I've been eating junk food more than I was eating regular food and guess what; unfortunately I dropped over 10 pounds unexpectedly, I used to eat a lot of leftovers long ago but now I'm just used to eating what I want now. But currently I'm now working on getting back my size sooner or later. 😂😅💯😁😉👌🏾
There are two types of fatness... one is the fatty layer outside and the other is a fatty liver ..engorged with all sorts of rubbish ... the latter is the hardest to reduce ... Paul isn’t quite right here ... if you have 10 volts RMS of audio signal backed up with sufficient current reserves ... then a 4 ohm speaker will be 3 dB louder than a similar 8 ohm speaker
Yes, indeed this video is quite wrong. 3dB per doubling of power is why using 4 Ohms can make a big sense if you want to gain a bit SPL. In fact, in car stereo some like to use 1 Ohm speakers as you can gain 3x3 = 9dB total SPL in the lower voltage amps of a car. The point is that it’s not the voltage that makes the sound happen. Rather it’s the power and a Watt is one Joule of energy per second.
First time I dissagree with you. The Volume depends on the power transmitted into the pressure waves in the air. Loudspeakers are horribly bad at doing so, and the volume is mostly depending on the efficiency of the speaker. There is no clear relation between impedance and efficiency. If you take two identical speakers and put them in parallel you get half the impedance and double the power at a given voltage. That increases volume by 3dB, but when comparing different speakers we are normally talking different drivers and there are a lot of construction details that influence the efficiency. The movement of the membrane is done by a magnetic field produced by a current in the coil of the driver. This magnetic field acts against a static field of a permanent magnet. The input voltage divided by the impedance determines the current. But in general still the answer is NO to the initial question.
The question does not go into efficiency. For example: an 8 inch can be rated at 84db at both 4 and 8 ohms at 1w/1m or 86db and 84db, respectively. So, speaker specs also play a role. In car audio, efficiency and multiple drivers make a difference. Also, car audio amps are tuned by voltage as well in terms of matching the source’s output. So, yes, voltage does translate to cone movement but every driver is different. A tough question but a great answer.
full thumbs up for this one as i cant give a half thumbs up! because I think you went round the houses for a simple answer, unless im wrong with my comment below?
Wrong wrong wrong. Answer is yes. You will get double the power assuming your speaker can handle it without clipping. Double power = 3db more spl. I just lost respect for you to not know such basic stuff. And your explanation doesn’t even make sense. Your other videos are good. Just delete this one. Cheers
