Author Topic: Power handling vs. amp output  (Read 13369 times)

Offline RuralTom

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Power handling vs. amp output
« on: January 20, 2014, 12:18:53 PM »
Hi All,

   I hate asking stupid questions, but after searching the web for a bit I don't feel like I have any definitive answer...

   How do you know how much power a speaker can handle, how much amp output is too much?  I see my KG 5.2s say max 100, peak 500, is 100W as much as I can use ever?  I assumed so, but looking at other rigs here I see people putting massive watts through speakers that are rated on the lower as well.
    I see some of the speakers I might be interested in  in the future might be more power hungry, so I'd like to move up to the 200W range, but don't really want to blow out the Klipschses...

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Offline thuffman03

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Re: Power handling vs. amp output
« Reply #1 on: January 20, 2014, 12:56:05 PM »
I like amps that can out drive speakers.  The reason is that the amp will not run out of headroom.  More speakers are damaged buy having small amps being over driven than large amps blowing up speakers because of too much power.
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Offline hewlew1

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Re: Power handling vs. amp output
« Reply #2 on: January 20, 2014, 03:19:20 PM »
+1 with what thuffman said driving an amplifier past the point of clipping  will cook a tweeter faster than you can toast a marshmallow

Offline OCCD

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Re: Power handling vs. amp output
« Reply #3 on: January 20, 2014, 03:46:24 PM »
You can never have enough power. However, don't let drunk people touch anything of you are running massive amps... >:D
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Offline RnR

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Re: Power handling vs. amp output
« Reply #4 on: January 20, 2014, 04:18:13 PM »
I second what OCCD said..  Alcohol blew up a really nice sony receiver I had -- I was totally pissd.  It only takes one time..  I guess I am one of those people who keeps asking "hmm.. I wonder If I could push it a little further"  Now I have an amp that puts out around 250wpc but my speakers can apparently only handle 100 or so...But I havnt had any problems (so far)   Listen to your meters!  Plus hearing damage would really suck -- you still wanna be able to hear that sweet Junior's growl of yours dont cha?

OldiesButGoodies

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Re: Power handling vs. amp output
« Reply #5 on: January 20, 2014, 04:21:41 PM »
You can never have enough power. However, don't let drunk people touch anything of you are running massive amps... >:D

That includes Tom, the Proac woofer destroyer!   ^-^

Offline RuralTom

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Re: Power handling vs. amp output
« Reply #6 on: January 20, 2014, 05:34:39 PM »
So, within reason, this is just a user beware kinda thing, I guess....

I don't imagine I'd have a problem with too little power.  I was thinking of bridging 2 Adcom 5300s, for 160W power per channel, but want to make sure I won't fry the Klipsches.  It'll just be on me to make sure I keep myself, and any drunks, from cranking it up too hard.
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Offline Reverend

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Re: Power handling vs. amp output
« Reply #7 on: January 20, 2014, 05:46:03 PM »
It's always better to have more power then not have enough.  As Uncle Ben (Spiderman not the rice) said, "with great power comes great responsibility.  You won't run into this with your Klipsch's, but speakers with low sensitivity and require huge amounts of watts won't reach their full potential until you have the right amount of power.  Case in point; Pepe trying to run 150watt amps on those giant shit boxes.

Offline MacGeek

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Re: Power handling vs. amp output
« Reply #8 on: January 20, 2014, 05:49:04 PM »
Agree with everyone's comments.  I once had a MAC 2500 (500 watts/side, plus headroom) driving a pair of speakers rated at 100/channel with no issues.  Trust your ears-if anything sounds off, regardless of amplifier out put and power rating, back off the volume.  As some of us have learned, do not test the limits of your system when less than sober.  You can insert a fuse in the speaker wires, if your speakers have no protection (I may get blasted for suggesting this), even if temporarily to test performance limits.  While this can protect the system, it may nor protect the tweeters.
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Offline MacGeek

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Re: Power handling vs. amp output
« Reply #9 on: January 20, 2014, 05:51:21 PM »
Should have added, be careful with bridged amps, they may not handle low impedance speakers (below 8 ohms) well.
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Offline TNRabbit

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Re: Power handling vs. amp output
« Reply #10 on: January 20, 2014, 08:45:23 PM »
ALWAYS fuse your speakers.  Fuses are cheap~
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Offline GraphicFX

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Re: Power handling vs. amp output
« Reply #11 on: January 20, 2014, 08:46:19 PM »
I agree that too much power is better then not enough
I;m driving speakers rated at 150 watts with 530 watt amps

They seem to handle things just fine, If you are careful, things should be honky dorey

But keep the idiots and drunks away from the volume button.

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SunnyDaze

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Re: Power handling vs. amp output
« Reply #12 on: January 20, 2014, 09:27:19 PM »
First and foremost - In the words of Jeremy Clarkson, "Power!" Continuous power output is actually a statistical measure called the root mean square - RMS.

If you consider the graph of a sinusodial function as the output function of an audio amplifier, then the area under that function is equal to the power produced by said amplifier. As this function oscillates positive to negative, any periodic measurement would sum to zero as you would have equal positive and negative parts.

The S in RMS: The RMS measure avoids the above zero sum scenario by squaring of the output function at each point in the time domain (time domain is fancy talk for "when shit's happening") in order to guarantee that the value is positive.

The M in RMS: Since the function is a continuous wave that varies in amplitude with time, the values of all of the power measurements taken from the output function are added together and divided by the number of measurements taken over our time domain in order to achieve an average - or mean - value of the sums of the squares of the sampled values of the output function.

The R in RMS: Since all the power measurements needed to be positive in order to prevent the math telling us that the amp is putting out 0 power (again, due to sinusodial output), each of these measurements had to be squared. Since we are interested in continuous power, not continuous power squared, the square root of the mean of the sums of the squares is taken.

Root Mean Square - Literally, the square root of an average (mean) value that is calculated using data points whose values are all squared.

So you see, as an amplifier does it's thing, there is always that average output power value that is the RMS measure - A statistical measure. While RMS is all well and good, it is a very robust statistical measure and does not fare well when attempting to calculate peaks in amplifier output power.

When the load from your loudspeakers demand more current than the amplifier can supply, bad things happen.

Regarding dynamic power, it's far safer to have a solid state amplifier that is entirely too powerful for your speakers than one that has insufficient power. I said earlier that amplifier power is equal to the area under the graph of the output function of a given amplifier. When an amplifier "clips" it essentially produces an output signal that exceeds the ability of the amplifier to control, thus the wave function grows in amplitude to a point where the tops of the waves are chopped or "clipped" off flat.  When the tops are clipped off of a sine wave, the shape of each wave comes to resemble a rectangle instead of series of waves, dramatically increasing the area under the output function. As a consequence, power increases to dangerous levels as does distortion. Since solid state amps distort primarily in odd harmonics, the harsh clipping sound that we've all come to know and (not) love is created. A good rule of thumb is to look for an amplifier with at least 3db of headroom; such amplifiers can double their power when the demand necessary.

Tube amps tend to clip in even harmonics. Along with that and the fact that they have relatively low NFB, tubes exhibit what some folks call "soft clipping".

Based on what I've just said, I hope it's evident that you are better off running an amp that puts out 200W RMS and 450 watts peak on a set of speakers that are rated at 60W RMS input than you are a set of speakers rated at 250W RMS input with an amplifier rated at 30W RMS output.

Of course, loudspeaker impedance and loudspeaker sensitivity play a significant role in this process, but, I feel like I've already typed enough crap that nobody wanted to read in the first place.  >:D

Guys, I'm the farthest thing on Earth from an expert on this crap, feel free to correct any errors.
 :police:
« Last Edit: January 20, 2014, 09:34:27 PM by 8 Watts of Fury »

Offline MacGeek

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Re: Power handling vs. amp output
« Reply #13 on: January 20, 2014, 09:36:57 PM »


Guys, I'm the farthest thing on Earth from an expert on this crap, feel free to correct any errors.
 :police:

[/quote]

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Re: Power handling vs. amp output
« Reply #14 on: January 20, 2014, 09:39:02 PM »
Rowdy Roddy Piker!