Measuring power output of a speaker amp to the speaker?

solderdude

Grand Contributor
I have done this measured the Volt at the speaker inputs (Ac of course) and clamped the current with an AC Current clamp, . It gaves me 25 Volts and 4 Amp max.
This would mean 100W

Also the Power Input 230 watt was 100 Amp.
This would be 23kW... but lets assume you meant 100W then your amp would have 100% efficiency which would make it the only amp in existence that does this.
So quite obvious your measurements are incorrect and the reason is you use MUSIC as a test signal which contains peaks that are waaaayyyyy to short to be able to measure them using a regular volt- amp-meter.

But most here say this is an senseless thing.
It is not pointless IF the right test signals are used.
Music is NOT such a test signal.
Music output can ONLY be measured with an oscilloscope.
And even then this will only give you the peak voltage values but at least will show you if you are near clipping levels or what voltage peaks are present.
To even measure that you will have to know your way around scopes to be able to capture such peaks (playing with single shot or setting trigger levels).

When you really want the actual power measured you will ALSO need the current clamp (or a small series resistor) and a 2-channel scope and then you would have to calculate the power levels. As impedance vary (and mostly in the lows where the most of the power goes) the power is not that important.
All you need is the voltage peak levels, not the actual currents.

I would know what my speakers are needing Power not know if the amp clips.
They do not need power. You apply a voltage and it draws a current which will vary depending on frequency.
An amplifier is a voltage source with a voltage and current limit.

How much power is required (it is only about peak voltages) depends on how loud you play.

An 600/1200 8/4 Ohm rated Amps clips not with an 250 rms rated speaker
You can clip a 250W rated speaker with a 600W rated amp using music IF you play loud enough.

As said a few times..... IF you want to determine what power rating you need as a minimum to reach the desired levels (which is really what you want to know) then there are ONLY 2 ways to find that out.

When using MUSIC as a test signal you will need an oscilloscope and you need to measure the peaks occurring in the music signal. From there you can CALCULATE the required continuous voltage (is power rating).

When using test signal you can use a (cheap) multimeter but you NEED to do that with a dummy load. You should not do that using speakers !!!!

You would have to buy an 8ohm (500W dummy load (or lower rated for short measurements, you only need to measure during a few seconds).
I will tell you HOW to do this but only if you have such a dummy load. DO NOT attempt this method using speakers.

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antcollinet

Master Contributor
I thought double perceved volume is around +10dB, which would be x3 increase in power, not x10. So 1w, 2w, 4w would roughly sound twice as loud.
For power, dB is 10 x log10 (P1/P2).

If P1/P2 is 10, log10 of that is 1 - x 10 is 10dB

You are (I believe) thinking of volts where dB is 20 x log10(V1/V2). But power is proportional to the square of volts which is why the two formulae for dB are different. A multiple of 3.16 x V is 10 x P

antcollinet

Master Contributor
Or buy more sensitive speakrs, or go from 8 Ohm to 4 Ohm speakers?
When you go from 8 ohm to 4ohm speakers (at the same amplifier gain) that doubles the power - if the amp can deliver the current.

OP
N

NoxMorbis

Senior Member
For power, dB is 10 x log10 (P1/P2).

If P1/P2 is 10, log10 of that is 1 - x 10 is 10dB

You are (I believe) thinking of volts where dB is 20 x log10(V1/V2). But power is proportional to the square of volts which is why the two formulae for dB are different. A multiple of 3.16 x V is 10 x P
Yeah I get that now. I was messing up the doubling math -- like always. Sure, I see now, such as going from 1 watt to 2 watts doubles the power for +3dB, the doubling that to 4 watts is another 3dB, and then to 4 to 8 watts in another +3dB for a total of +9dB, but that's nearing x10 power of 1 watt for +10dB or a perceived doubling of loudness. Thanks for calling me on that!

Mario Soldier

Member
It's not quite fudging, sort of. It's just not the usual standard. As I mentioned before, seems Klipsch explains it as an in-room equivalent instead of a non-reverberant environment. Sometimes it's more than 4-5 dB, too.

Here's a review of the RP8000F...note the comment in "Cons" of 92.8 dB sensitivity and James' explanation in the measurements section as to why that's still fine despite an advertised 98 dB sensitivity due Klipsch methodology https://www.audioholics.com/tower-speaker-reviews/klipsch-rp-8000f

Here's a Stereophile review of the RP600M with another comment about sensitivity https://www.stereophile.com/content/klipsch-reference-premiere-rp-600m-loudspeaker-measurements

There are others, those were just quick to find.

I have the RP 800 F to i use them for Back Sourrounds an RP 600 F for Soourrounds.

Possible i schouild change the six Yamha NS 100 to KLisch RP 600 M for Atmos

antcollinet

Master Contributor
And I'd say most of that power in the electronic music was in the bass.

RayDunzl

Grand Contributor
Central Scrutinizer
If you want to see if clipping occurs with music...

And you have an oscilloscope with two channels...

Use the lissajou function.

One channel drives the trace left and right, the other channel drives the trace vertically.

Stereo input will drive the trace in a somewhat random looking circular motion.

If electrical clipping occurs it is obvious, as the rounded trace will be flattened at the edges or squared off at the corners.

antcollinet

Master Contributor
So?
Like always. (Nearly).
So? It was an excessively bass heavy track. I don't think I have any music like that.

Sure - some people need 500+ watts for listening at high volume. Many more don't.

Holdt

Major Contributor
So? It was an excessively bass heavy track. I don't think I have any music like that.

Sure - some people need 500+ watts for listening at high volume. Many more don't.
Yeah it was. With lots of dynamics. I think many EDM tracks is similar in demand so I don't think it's out of the ordinary when you have large bass drivers in towers and play loud(ish).

OP
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NoxMorbis

Senior Member
I have the RP 800 F to i use them for Back Sourrounds an RP 600 F for Soourrounds.

Possible i schouild change the six Yamha NS 100 to KLisch RP 600 M for Atmos
Do you live in a mansion? LOL, damn that's a lot of SPL potential.

OP
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NoxMorbis

Senior Member
Sure - some people need 500+ watts for listening at high volume. Many more don't.
Not for long. Soon they will need 5000 watts. (Because they are going deaf.)

You don’t have to attend every argument offered
Moderator
Forum Donor
Not for long. Soon they will need 5000 watts. (Because they are going deaf.)

antcollinet

Master Contributor
Not for long. Soon they will need 5000 watts. (Because they are going deaf.)
They will most likely go quickly and totally deaf if they pump 5000W into their speakers.

OP
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NoxMorbis

Senior Member
They will most likely go quickly and totally deaf if they pump 5000W into their speakers.
LOL, Oh believe me. I understand. As a young adult, we spent literally hours in our cars listening to heavy metal and rock at levels that would stun a small farm animal. I think Judas Priest's "Screaming For Vengeance" is genetically embedded in my DNA from repeated blunt force SPL trauma.

OP
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NoxMorbis

Senior Member
You can do it the way an engineer does it ..... or you can watch this video. It may give you some rough ideas.

Jim
Thank you. I'll watch it!

mhardy6647

Master Contributor
...

Measuring something is only useful when done right (correct signals, measurement gear and protocols) otherwise it is somewhat indicative at best.
I'm waiting for the smart phone as laboratory instrument suite crowd to realize this.

Chrispy

Master Contributor
Forum Donor
I have the RP 800 F to i use them for Back Sourrounds an RP 600 F for Soourrounds.

Possible i schouild change the six Yamha NS 100 to KLisch RP 600 M for Atmos
Couldn't tell you what your preferences might be. Altho I'm wondering why you don't use the RP800F for surround and the RP600F for rear surround. Not familiar with the Yamahas at all. You wouldn't do in-ceiling for Atmos?

OP
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NoxMorbis

Senior Member
You can do it the way an engineer does it ..... or you can watch this video. It may give you some rough ideas.

Jim
I just watched this which confirms my own tests about loudness and power. However, the host was saying that what we should be worried about is not watts, but how fast the amp can deliver the power when needed. What measurement is that?

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