Understanding watts, current(amps), and voltage

ensitmike

ensitmike

Enthusiast
I am fairly new to all this, but in my research I have run across multiple people that say a high watt amp will “awaken” “liven” and “up performance” of speakers even at low listening levels. E.g. A speaker at the same volume will sound better and "fuller" from a 200watt amp than a 50watt amp even if both have high current ratings.

Is this real?

I understand the fundamental difference between current and watts, however is it correct that when we turn up the volume knob the greater determining factor is the voltage rather than the current? If this is the case, then does high watts really matter or is something else going on?

If I'm not mistaken then the only time I can see a 200 watt amp performing better is when volume levels exceed the 50 watt amp capabilities.

Thanks for any clarification.
 
L

Leemix

Senior Audioholic
At lower volumes it may depend on how much pure class A before going AB. Good quality amps usually have much better heat dissipation with big cooling fins and such so can run more heat producing class A watts.

It doesnt take all that much at moderate/higher volumes to go past the comfort zone of a 50w amp unless very sensitive speakers.


Sent from my iPad using Tapatalk
 
Swerd

Swerd

Audioholic Spartan
I am fairly new to all this, but in my research I have run across multiple people that say a high watt amp will “awaken” “liven” and “up performance” of speakers even at low listening levels. E.g. A speaker at the same volume will sound better and "fuller" from a 200watt amp than a 50watt amp even if both have high current ratings.

Is this real?
It isn't correct to say "a high watt amp WILL awaken, liven, or up the performance of speakers even at low listening levels". But if you said CAN awaken… you'd be more correct.

This depends heavily on a speaker's sensitivity and impedance, as well as a speaker's ability to handle high power. How easy or difficult is it to drive them to loud levels? How much high power can a speaker handle before something, usually the voice coil, fails?

50 watts may be plenty for speaker X, but 200 watts may be needed for speaker Y. If a less powerful amp has juice left over as speaker responds to the loud but often very brief demands of the music, then a more powerful amp will not make a difference. But if the amp runs out of juice before the speaker responds, and if that speaker can handle higher power, then a more powerful amp can make a difference.

When an amp runs out of juice while trying to drive a speaker loud, it is said to go into clipping.
1579969410698.png

Amps and speakers run on alternating current (AC) signals. Where the sine waves in the figure are clipped off, the signal becomes direct current (DC). DC signals are not good for speakers, especially fragile tweeters.

I hope that explanation helps. To learn more about clipping in audio see this
 
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P

PENG

Audioholic Overlord
I am fairly new to all this, but in my research I have run across multiple people that say a high watt amp will “awaken” “liven” and “up performance” of speakers even at low listening levels. E.g. A speaker at the same volume will sound better and "fuller" from a 200watt amp than a 50watt amp even if both have high current ratings.

Is this real?

I understand the fundamental difference between current and watts, however is it correct that when we turn up the volume knob the greater determining factor is the voltage rather than the current? If this is the case, then does high watts really matter or is something else going on?

If I'm not mistaken then the only time I can see a 200 watt amp performing better is when volume levels exceed the 50 watt amp capabilities.

Thanks for any clarification.
Funny you ask.. I have been wanting to write a page on this very topic.

For now, I would suggest if you understand basic electrical principles, Google the topic yourself for knowledge but stick with reputable technical sites and don't trust forum talks too much.

You got it right that voltage and current are more relevant then watts for audio amp talks, though they are all related. The spl produced by speakers are directly related to the applied voltage. In extreme cases, a speaker may draw very high current yet consumed very little watts. In such case, the amp will end up dissipating a lot of watts in the form of heat internally.
 
ensitmike

ensitmike

Enthusiast
It isn't correct to say "a high watt amp WILL awaken, liven, or up the performance of speakers even at low listening levels". But if you said CAN awaken… you'd be more correct.

This depends heavily on a speaker's sensitivity and impedance, as well as a speaker's ability to handle high power. How easy or difficult is it to drive them to loud levels? How much high power can a speaker handle before something, usually the voice coil, fails?

50 watts may be plenty for speaker X, but 200 watts may be needed for speaker Y. If a less powerful amp has juice left over as speaker responds to the loud but often very brief demands of the music, then a more powerful amp will not make a difference. But if the amp runs out of juice before the speaker responds, and if that speaker can handle higher power, then a more powerful amp can make a difference.

When an amp runs out of juice while trying to drive a speaker loud, it is said to go into clipping.
View attachment 33608
Amps and speakers run on alternating current (AC) signals. Where the sine waves in the figure are clipped off, the signal becomes direct current (DC). DC signals are not good for speakers, especially fragile tweeters.

I hope that explanation helps. To learn more about clipping in audio see this

Great explanation. Thank you for that.

This is more or less what I thought, but you cleared up something I had wrong. Up till now I thought clipping was when the speaker reaches it's limit, but that makes much more sense that the amp is the component that clips.

All good info to know.
 
ensitmike

ensitmike

Enthusiast
At lower volumes it may depend on how much pure class A before going AB. Good quality amps usually have much better heat dissipation with big cooling fins and such so can run more heat producing class A watts.

It doesnt take all that much at moderate/higher volumes to go past the comfort zone of a 50w amp unless very sensitive speakers.


Sent from my iPad using Tapatalk
Good stuff to know. I actually have heard A and A/B talk but haven't go around to looking into it. I'll read up on it now.
 
ensitmike

ensitmike

Enthusiast
Funny you ask.. I have been wanting to write a page on this very topic.

For now, I would suggest if you understand basic electrical principles, Google the topic yourself for knowledge but stick with reputable technical sites and don't trust forum talks too much.

You got it right that voltage and current are more relevant then watts for audio amp talks, though they are all related. The spl produced by speakers are directly related to the applied voltage. In extreme cases, a speaker may draw very high current yet consumed very little watts. In such case, the amp will end up dissipating a lot of watts in the form of heat internally.
Nice! I'll keep an eye out.

Where do you publish your write-ups?
 
lovinthehd

lovinthehd

Audioholic Slumlord
I'd sure like a demo of a speaker that sounds particularly different at low listening levels between a 50wpc amp and a 200wpc amp (assuming ss rather than tube).
 
P

PENG

Audioholic Overlord
Nice! I'll keep an eye out.

Where do you publish your write-ups?
Don't wait for me, it may take a long time or never... It is difficult to write a one page article on something as complicated as this.

I am fairly new to all this, but in my research I have run across multiple people that say a high watt amp will “awaken” “liven” and “up performance” of speakers even at low listening levels.
I would ignore such claims if stated as a blanket statement, but it could be valid if qualified by specifying the underlying reasons and/or conditions. For example, the specs of the speaker used, listening conditions such as room size, seating distance, and the definitions of "high watt amp", and "low listening levels".

E.g. A speaker at the same volume will sound better and "fuller" from a 200watt amp than a 50watt amp even if both have high current ratings.

Is this real?
It depends on what they meant by "...volume...", "high current ratings..". So a yes/no answer is not possible without knowing the full specifications of the speakers and amplifiers being used and the "volume" defined.

I understand the fundamental difference between current and watts, however is it correct that when we turn up the volume knob the greater determining factor is the voltage rather than the current? If this is the case, then does high watts really matter or is something else going on?

If I'm not mistaken then the only time I can see a 200 watt amp performing better is when volume levels exceed the 50 watt amp capabilities.

Thanks for any clarification.
I dare say not too many (I assume you are one of those who do..) audio hifi/ht enthusiasts really understand a lot of on this topic, but you don't need to understand a whole lot of any of it either just to enjoy your favorite music and movies. For those interested in the "relationship" between voltage, current, phase angle/power factor, watts, VA (volt-amp, that often shows up in power transformer specs..) in their applications in audio amplifiers, sengpielaudio.com is a good resource. Below are some good articles to read, the last one may be a little more difficult to understand for non EEs, but it is still a good read for someone who has the basic knowledge. Imo, it is a must read if you want to understand the different effects the nature of the load impedance (i.e. that a complex/reactive load) such as a moving coil loudspeakers would present to the driving amplifier.

sengpielaudio.com articles (you may want to skip the first one or two since you already know the stuff):

Ohm's law

Power formulae

Phase angle and power dissipation
 

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