how get rated audio amplifier output

[Mohit pal]

I am using PAM8106 amplifier IC with an 8 Ohm speaker with 12v supply, but I am unable to get 10w output .what could be the reason for not achieving the rated 10W output power?

 

[Digital_Thor]

Just from the top of my mind, maybe the power supply you use, can't deliver enough current, so it might have 12V but not enough amperage?
So when you load the output of the amplifier, you drain the power supply.
How do you measure that you do not have 10W?

You could measure the current of the power supply or maybe the voltage drop during a load test, to see if it is in fact the power supply that is not "strong" enough.

 

[audio_tony]

How are you measuring the power output? Do you have an 8 ohm dummy load?

Are you measuring power with a multimeter or oscilloscope? If using a multimeter, you should be measuring at a frequency of around 500Hz as most multimeters (unless really top quality) won't be accurate above 1kHz or so on the AC range.

To calculate the RMS power from voltage at speaker terminals, use the following equation V(squared) / impedance.
So if you measure 8v RMS at the speaker terminals, 8 * 8 / 8 = 8w.

To get 10w from the PAM8106 at 12 volts, the THD will be 10%, so realistically it's only good for around 8 to 9w max.

For your measurements to be remotely accurate, yo uneed to observe the waveform on an oscilloscope and watch for the onset of clipping, and then mesaure the RMS voltage at that point.

 

[Mohit pal]

Just from the top of my mind, maybe the power supply you use, can't deliver enough current, so it might have 12V but not enough amperage?
So when you load the output of the amplifier, you drain the power supply.
How do you measure that you do not have 10W?

You could measure the current of the power supply or maybe the voltage drop during a load test, to see if it is in fact the power supply that is not "strong" enough.

I am using 12V ,6A power supply. and use multimeter for measure output voltage and calculate the output power by V*2/R

 

[Mohit pal]

How are you measuring the power output? Do you have an 8 ohm dummy load?

Are you measuring power with a multimeter or oscilloscope? If using a multimeter, you should be measuring at a frequency of around 500Hz as most multimeters (unless really top quality) won't be accurate above 1kHz or so on the AC range.

To calculate the RMS power from voltage at speaker terminals, use the following equation V(squared) / impedance.
So if you measure 8v RMS at the speaker terminals, 8 * 8 / 8 = 8w.

To get 10w from the PAM8106 at 12 volts, the THD will be 10%, so realistically it's only good for around 8 to 9w max.

For your measurements to be remotely accurate, yo uneed to observe the waveform on an oscilloscope and watch for the onset of clipping, and then mesaure the RMS voltage at that point.

View attachment 459151

using 8ohm 10W speaker for load and measure output voltage at speaker with using multimeter and calculate power by v²/r. Input audio source 1Khz frequency.

 

[audio_tony]

using 8ohm 10W speaker for load and measure output voltage at speaker with using multimeter and calculate power by v²/r. Input audio source 1Khz frequency.

Although the 8ohm speaker measures 8 ohm DC resistance, at 1kHz the impedance could range from 3 ohms to 12 ohms or more.

This is why it's important to use a resistive load when measuring power.

What are you using to determine the onset of distortion? If you don't have access to a 'scope, then you are relying on your ears to determine the onset of distortion.

Also, with class D the power can typically vary more with load impedance than a class AB design for example.

 

[Mohit pal]

Although the 8ohm speaker measures 8 ohm DC resistance, at 1kHz the impedance could range from 3 ohms to 12 ohms or more.

This is why it's important to use a resistive load when measuring power.

What are you using to determine the onset of distortion? If you don't have access to a 'scope, then you are relying on your ears to determine the onset of distortion.

Also, with class D the power can typically vary more with load impedance than a class AB design for example.

Although the 8ohm speaker measures 8 ohm DC resistance, at 1kHz the impedance could range from 3 ohms to 12 ohms or more.

This is why it's important to use a resistive load when measuring power.

What are you using to determine the onset of distortion? If you don't have access to a 'scope, then you are relying on your ears to determine the onset of distortion.

Also, with class D the power can typically vary more with load impedance than a class AB design for example.

can you please suggest a complete test setup for my PAM8106 (10w amplifier) .what should be the audio input (source and strength) and output load for achieve rated output.