Amplifier wattage - An interesting way of explanation.

spaace

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Nice video. However, they are not playing anything with bass in it. Could that be the reason why the watts is so low ?
 

arj

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Nice video and this is in line with what Paul W Klipsch said that its the first watt that matters and what really defines the amplifiers sound

Although 87db is not the right measure of a speaker as its impedance curve as well as Phase curves are also very important which defines power consumption.the sibelious might be a easy to drive speaker ( like the harbeths despite 86-89 dB).
 

sunilj

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With Joppa's "102dB rule", its easy to understand why low power amps work with some speakers and not always.
 

Nippy

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Nice video. However, they are not playing anything with bass in it. Could that be the reason why the watts is so low ?
I think more wattage, not too many, would benefit the dynamics for sure. But considering that most of us would listen at sane volumes so that should reduce the "need" for more wattage.
 

sunilj

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With Joppa's "102dB rule", its easy to understand why low power amps work with some speakers and not always.
That's from the bottlehead forum. Here's a copy as-is.

Simplistic summary:

1) Most ordinary solid-state amps put out more than enough power for most ordinary speakers.

2) SET amps need high efficiency speakers to attain the loudness most audiophiles want.

Over the years, I have tried to gather enough data to make those vague rules more specific. It is complicated (isn't everything?!) by the notion of headroom. Loudness is measured typically as a short-term average, over something like 1/4 second. But the instantaneous peak power, for example hitting a drum, or the initial impulse of a guitar or piano, is much greater. For well-recorded music, the initial impulses are about 25 times more power than the peak you see on the loudness meter. That's about 14dB headroom. So if you listen at a level that gives measured peaks of 82dB, you need an instantaneous peak of 96dB if you do not want to hear clipping distortion. I chose 82dB because that is typical of the level used by recording engineers. Movies typically need 6dB (four times as much, i.e. 102dB). The THX standard for movie theaters calls for peak levels of 102dB per channel, which is consistent with the recording engineer levels. Some 20 years ago, I gathered a bunch of speaker reviews from Stereophile, which give a minimum-power rating and the speaker sensitivity. I got the same number (102dB peaks) again. So I think that 102dB peaks is enough for most audiophiles, most of the time, and 96dB peaks are enough for the average audiophile. These numbers are somewhat affected by room acoustics (size and absorption), and more strongly affected by your personal preferences and choice of music.

Amplifier power is most usefully expressed in dB, which can be added to the speaker sensitivity to get the peak level. Here's a short table:

1 watt = 0dB
2 watts = 3dB
4 watts = 6dB
8 watts = 9dB
16 watts = 12dB
32 watts = 15dB
64 watts = 18dB

So for example an 86dB speaker needs 10 to 40 watts to obtain undistorted peaks of 96 to 102dB.
 

veekm

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During my late night random youtube surfing, found this interesting method of explanation on amplifier wattage. Though the channel is pretty "young" it sure has interesting content. Link: Amplifier wattage.
(nice video just a note of caution) he's one of those people that believe in oxygen free cables and such for audio - I also suspect that he has not a very good idea about quantum electronics, crystal structure of metals/Millers indices and electrons based on this video:
Pearl Acoustics

 

Nippy

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(nice video just a note of caution) he's one of those people that believe in oxygen free cables and such for audio - I also suspect that he has not a very good idea about quantum electronics, crystal structure of metals/Millers indices and electrons based on this video:
Pearl Acoustics

Well we live in a world where everone has a right to his/her own belief... and it is fine if he doesn't know about the electrons and what not... many of us dont.. but we do trust our ears... if the ofc makes a difference for someone.. good for them.. if it does not... all the more good.. you save some $$$$$ :)
 
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