Measuring power output of a speaker amp to the speaker?

[Mario Soldier]

I cannot answer those questions.



Is it only to view a clipping level of speaker signals (10-100V AC) or for more serious measurements as well ?

The first nobody can answer this Question.... i also can not.This is why is have the idea to go with an better amp or go with two amps and an Switch on for movies and one for Stereo Power.many Oem manufacturers say, they nerv would use icepower modules .Others does.

https://d2digq31msfd9c.cloudfront.net/uploads/manuals/Legacy_Audio_2020_iV_Ultra_Manual_9_8_2020-compressed.pdf?mtime=20210302135955&focal=none

https://d2digq31msfd9c.cloudfront.net/uploads/manuals/Powerbloc-Amplifiers-Manual-2021_opt.pdf?mtime=20210216164050&focal=none

Side 11 why you choosed icepower.


Not sure what i can measure with an ociloscope but in first place, yes the clipping problem.


Problem is , can is measure clipping while playing music with an amp on my speakers?

Amis testd the clipping of most modules it is known.

 

[Mario Soldier]

Bigest Problem is, i will not measure if an amp clips (some of my amps have clipping indicators)

In First way i will know how much wattage my speakers will use when i play loud music (with 3-5 db dynamics there is no more) .

So iam able to choose the right Power Amp .

I only know 3 things a single Pascal spro2 rated 250/500 clips (very late but it clips) also am UCD400 Dual MOno Amp Clips .I know that because the amps have indicators.

And i know if i am using 2 pascal Spro 2 modules in BTL Mode i am far away from clipping, very far, sure that i dont need this power the speaker would break at full power.

If the only way measuring with an ocilloscope i have to do that, Ok i could buy two buckey ET400 Monos they have clipping indicators and try it.If they clip i use them at another place.

Jeff Rowland 535 Stereo Amplifier Review

This is a review and detailed measurements of the Jeff Rowland 535 stereo (bridgeable) amplifier. It is on kind loan from a member. I believe it costs US $5,900. If you are not familiar with Jeff Rowland, it is a high-end audio company, known for their gorgeous machining of their cases that...

www.audiosciencereview.com

Amir tested the Pascal Spro 2 Modul but only with 120 Volt.

He measured 279 Watt before clipping at 4 Ohm but the module is oly rated with 700 Watts complete with 120 Volt and ist is rated with 1000 Watts with 230 Volts.

I have 230 Volts , Amit had an max Power measured ca 350 Watt but an Test with 240 Volt says 506 Watts.

Can i connect an Purifi Amp to my skeakers an then test with Test Eupiment if it will clipping at loud levels?

Amis says ist clips at 280 Watt 4 Ohm,not sure if this is enough for driving my speakers to the max level

 

[solderdude]

Problem is , can is measure clipping while playing music with an amp on my speakers?

Yes, it is seen as a signal level not going past a certain voltage level and 'flattening' the signal.
The only proper way of measuring clipping IRL with actual loads using music.

Something like this will do this already. You may have to use an attenuator.

You could even use a soundcard + attenuator + some calibration along with a computer program that turns your PC into an oscilloscope.

 

[Mario Soldier]

Please Note: If used with a BTL amplifier, never try to use an oscilloscope to measure the peak power, as scopes are always grounded for safety. Connecting a grounded oscilloscope may cause amplifier failure, and may also damage the oscilloscope and/ or the scope lead. If you have a differential probe that provides total isolation that may be used, but few hobbyists will have one as they are very expensive.

BTL Amplifiers
There are some special precautions that you must be aware of before using the power meter with a BTL (bridge-tied load) power amp. Because both outputs carry a signal, you must not connect an oscilloscope, because the ground clip will place a short on one amplifier output! You can't use a transformer to couple the instantaneous power output to an oscilloscope either, because the output is 'unipolar' (of one polarity) and it basically carries a continuously varying DC offset. While a 1:1 transformer could (in theory) be capacitively coupled, the output as displayed on a scope would be extremely difficult to interpret.

It is possible to provide an optically coupled output that will perform to DC, but that's not a simple undertaking. It is something that I may look into further at some point (I've already done some research and there are several solutions, some better than others). You can buy a complete isolated amplifier, but the cost is considerable. Analog Devices make one, the AD215AY Isolation Amplifier, in a 12-Pin SIP (single inline pin) package, but at almost AU$150 each (at the time of writing) that's probably not something that most people will be prepared to purchase.

So, if you do need to test with a BTL amplifier, you'll be able to read the average power on a meter, but looking at the peak power isn't a viable option. Since the idea is primarily to characterise loudspeakers rather than amplifiers, use a 'conventional' power amp so there are no problems examining the peak output. Using a BTL amplifier that doesn't allow you to measure the peak voltage and current on an oscilloscope is very limiting.


Thats of course an problem,it seems it is not so easy using an ociloscope on an BTL Ampifier.

Most Icepower Amps are BTL Amps even if they have two channels . Couse of this icepower Amplifiers can not be bridged couse they are running in BTL Mode.
This has some advantages ans some disatvantages.

You dont need an DC Blocking Capacitor for example. And with an one channel am the smsps is not pumping.

 

[NTK]

Please Note: If used with a BTL amplifier, never try to use an oscilloscope to measure the peak power, as scopes are always grounded for safety. Connecting a grounded oscilloscope may cause amplifier failure, and may also damage the oscilloscope and/ or the scope lead. If you have a differential probe that provides total isolation that may be used, but few hobbyists will have one as they are very expensive.

BTL Amplifiers
There are some special precautions that you must be aware of before using the power meter with a BTL (bridge-tied load) power amp. Because both outputs carry a signal, you must not connect an oscilloscope, because the ground clip will place a short on one amplifier output! You can't use a transformer to couple the instantaneous power output to an oscilloscope either, because the output is 'unipolar' (of one polarity) and it basically carries a continuously varying DC offset. While a 1:1 transformer could (in theory) be capacitively coupled, the output as displayed on a scope would be extremely difficult to interpret.

It is possible to provide an optically coupled output that will perform to DC, but that's not a simple undertaking. It is something that I may look into further at some point (I've already done some research and there are several solutions, some better than others). You can buy a complete isolated amplifier, but the cost is considerable. Analog Devices make one, the AD215AY Isolation Amplifier, in a 12-Pin SIP (single inline pin) package, but at almost AU$150 each (at the time of writing) that's probably not something that most people will be prepared to purchase.

So, if you do need to test with a BTL amplifier, you'll be able to read the average power on a meter, but looking at the peak power isn't a viable option. Since the idea is primarily to characterise loudspeakers rather than amplifiers, use a 'conventional' power amp so there are no problems examining the peak output. Using a BTL amplifier that doesn't allow you to measure the peak voltage and current on an oscilloscope is very limiting.


Thats of course an problem

Yes. One must be very careful when measuring amplifier output with an oscilloscope. However, if you don't have access to differential probes (The cheaper ones are usually made for high voltage measurements. They have very large attenuations, and aren't very suitable for amplifier output measurements.), you can use two single ended channels for one differential channel measurement if your oscilloscope support math functions. See @Philbo King 's earlier post (post #79).

Measuring power output of a speaker amp to the speaker?

Klipch R51-M + Kanto sub8 Klipsch spec'd sensitivity is overstated by 4-5dB compared to what most others do (Klipsch uses an "in-room" equivalent spec).

www.audiosciencereview.com

 

[solderdude]

Please Note: If used with a BTL amplifier, never try to use an oscilloscope to measure the peak power, as scopes are always grounded for safety. Connecting a grounded oscilloscope may cause amplifier failure, and may also damage the oscilloscope and/ or the scope lead. If you have a differential probe that provides total isolation that may be used, but few hobbyists will have one as they are very expensive.

The scope I mentioned is not connected to mains and not the source for the test signal.
Also in BTL mode you can measure just 1 of the outputs to ground which means you can even use a grounded scope.

 

[Mario Soldier]

The scope I mentioned is not connected to mains and not the source for the test signal.
Also in BTL mode you can measure just 1 of the outputs to ground which means you can even use a grounded scope.

Ok think i understand (not 100% sure, have to read more).

Amazon.com

Problem is the Ociloskope is not aviable and of course not in germany i hafe to find something on amazon.de Or in Europe.
Possiblle i buy a better one for measuring something other things 200-300 euro is Ok, but iwill not speds thousands of euros for it ( its cheaper buying an big amp).

But possible a buy an cheap one only for measuring the output of the amp an when i have more expirience i buy an better one.
The first has to be easy to handle......


If I have an Ociloscope what is Ok,can you say me where i have to connect it?I haveno idea about at this moment.Learning handling an ociloscope is a good thing for me possible i can use it at car electronics.

So what he is doing here is useless???(they are many useless videos on youtube i know it from car repair....)
But he is measuring only one driver probyly that is OK.

LOl he Clamps two wires....... but it seems it are the two positives thats OK.

 

[solderdude]

Measuring DC current and continuous sinewave under a load that can handle the continuous power you can use multimeters.
Alas the clipping point of continuous and music may not be the same (it will be for class-D when not exceeding the power supply currents.

 

[NoxMorbis]

Klipsch spec'd sensitivity is overstated by 4-5dB compared to what most others do (Klipsch uses an "in-room" equivalent spec).

Dunno. I haven't seen those tests myself.

 

[NoxMorbis]

Not necessarily. You need to go 10x in power to roughly double the percieved volume.

So 1/3W for your normal fairly low volume. 3W for double that. 30W to double it again (We are talking percieved volume, not watts or spl here)

So your 25W is less than 4 times louder (percieved) than your 1/3 watt.

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.

 

[NoxMorbis]

View attachment 288982

Shows it was pretty accurate roughly. thanks.

 

[Mario Soldier]

Dunno. I haven't seen those tests myself.

My Rf7 MK3 are rated 100 db but measurement says they are only 92,8 db sensitivity speakers.

They are rated 250 OHm and max output is 117 db

 

[NoxMorbis]

When you need the sound to go noticeably louder you need to increase the power 2 to 3 fold at least.
Adding a few percent in power won't help.

Or buy more sensitive speakrs, or go from 8 Ohm to 4 Ohm speakers?

 

[NoxMorbis]

My Rf7 MK3 are rated 100 db but measurement says they are only 92,8 db sensitivity speakers.

They are rated 250 OHm and max output is 117 db

What measurements? I've heard Klipsch fudges it's sensitivity numbers, but never came across a test that proves it. I haven't really looked though. Interested now

 

[Mario Soldier]

What measurements? I've heard Klipsch fudges it's sensitivity numbers, but never came across a test that proves it. I haven't really looked though. Interested now

https://www.henleyaudio.co.uk/shop/product/viewfile?FileId=4754&ProductId=937

 

[Mario Soldier]

Also Buckes says he can not bridge the NCx 500 Modules....


Hypex says when i bridge the Nilais with two seperate Power suppiels they are 800-1000 Watt at 8 Ohm

Possible the max Power output of the Rf7 is higher they are rated 8 Ohm but are more like 4 OHm, they go loud enough.

With twi icepower 1200As1 They are really loud, the Question is are the also so loud with two NCx 500 Monoblocks.....

I use the KLipsch with an AVr Preamp and active room measurement, and my room is accousticly modified.

 

[Hayabusa]

Combined rms volt measurement on the speaker terminals and a current clamp on on the wires seems to be the most elegant way.
With a sine wave as source it would also give you the impedance at that frequency (if the load is not too complex).
If you could syncronously sample both signals and do an fft you could do this for any signal and have power and impedance per frequency bin.
This would also give you the complex impedance as output.
Sounds like a nice product/project!

 

[Mario Soldier]

Combined rms volt measurement on the speaker terminals and a current clamp on on the wires seems to be the most elegant way.
With a sine wave as source it would also give you the impedance at that frequency (if the load is not too complex).
If you could syncronously sample both signals and do an fft you could do this for any signal and have power and impedance per frequency bin.
This would also give you the complex impedance as output.
Sounds like a nice product/project!

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.

Also the Power Input 230 watt was 100 Amp.

But most here say this is an senseless thing.


I would know what my speakers are needing Power not know if the amp clips.
Also i am not interested in max Power output of the amp,i know it....

An 600/1200 8/4 Ohm rated Amps clips not with an 250 rms rated speaker

 

[sam_adams]

@NoxMorbis, what you need is a clamp on o-scope probe like this one. That allows you to measure the output current. You would need a way to provide a sine sweep to the amp—REW could foot the bill there. If the Hantek probe has a compatible voltage level, you could feed the output from the probe into a soundcard input and have a frequency-to-current plot. You would then have to compare the current plot to the speaker impedance at the frequencies of interest to calculate the power. If you have an impedance vs. frequency sweep of the speaker, you could input all the data into GNU Octave to have it draw some graphs for you.

 

[Chrispy]

What measurements? I've heard Klipsch fudges it's sensitivity numbers, but never came across a test that proves it. I haven't really looked though. Interested now

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.