Hello-
I have recently purchased an AKER all in one speaker/power supply/amplifier.
It is called Portable Waistband Voice Booster PA Amplifier AK-38.
It comes with a wall wart (AC to DC) which has written on it 9.5VDC and 350mA. I measured the actual input at 9.5VDC and at the loudest volume 250mADC.
Written in the specifications, the current consumption is 150mA, and the output peak power is RMS 25 Watts. How is the output peak power 25 Watts (9.5VDC * 150mA is < 25 Watts) ? And further, how is RMS 25 Watts the same thing as output peak power? And is there any such thing as RMS Watts?
Signed,
Confused
I have recently purchased an AKER all in one speaker/power supply/amplifier.
It is called Portable Waistband Voice Booster PA Amplifier AK-38.
It comes with a wall wart (AC to DC) which has written on it 9.5VDC and 350mA. I measured the actual input at 9.5VDC and at the loudest volume 250mADC.
Written in the specifications, the current consumption is 150mA, and the output peak power is RMS 25 Watts. How is the output peak power 25 Watts (9.5VDC * 150mA is < 25 Watts) ? And further, how is RMS 25 Watts the same thing as output peak power? And is there any such thing as RMS Watts?
Signed,
Confused
Hi Nora,
After looking at that site, all I can say is either they don't know what they are talking about or they are lying. On a fully charged battery, the absolute maximum power that unit could deliver even if the amp is 100% efficient (none are), would be 15 watts. Clearly, it is impossible to get anything close to what they claim. Also that site is full of information that is wrong and/or misleading, much of what is claimed is non-sense. If your unhappy with the way it performs, I would recommend trying to return it for a refund. Otherwise, if it suits your needs and performs OK, just chalk it up to deceptive marketing and move on. And yes, amplifier power is usually expressed as RMS power, at least when dealing with reputable distributors. Hope this helps.
Mike
After looking at that site, all I can say is either they don't know what they are talking about or they are lying. On a fully charged battery, the absolute maximum power that unit could deliver even if the amp is 100% efficient (none are), would be 15 watts. Clearly, it is impossible to get anything close to what they claim. Also that site is full of information that is wrong and/or misleading, much of what is claimed is non-sense. If your unhappy with the way it performs, I would recommend trying to return it for a refund. Otherwise, if it suits your needs and performs OK, just chalk it up to deceptive marketing and move on. And yes, amplifier power is usually expressed as RMS power, at least when dealing with reputable distributors. Hope this helps.
Mike
That previous company said they would change their spec!
Now I have a new company, one that I believe is reputable, Crutchfield.
I bought this one.
The spec is amplifier power 80 Watts continuous and max 160 Watts.
I measure input power of 12V and 2A. I don't have a way to measure my signal volts...it is coming out of a Samsung mp3 player into the Amplifier/subwoofer.
The technical support folks tell me that acoustical Watts are different than electrical Watts.
True? Or not?
They also tell me that the amplifier is there to amplify power.
So you can get more energy out than you put in?
Still confused...
Nora
Now I have a new company, one that I believe is reputable, Crutchfield.
I bought this one.
The spec is amplifier power 80 Watts continuous and max 160 Watts.
I measure input power of 12V and 2A. I don't have a way to measure my signal volts...it is coming out of a Samsung mp3 player into the Amplifier/subwoofer.
The technical support folks tell me that acoustical Watts are different than electrical Watts.
True? Or not?
They also tell me that the amplifier is there to amplify power.
So you can get more energy out than you put in?
Still confused...
Nora
Who would have thought the answer to the global energy situation was in audio amplifiers!
*chuckle*
If an amplifier produced more at it's output terminals than it took from the wall socket then it would be operating at more than 100% efficiency, something that is impossible. They've just confused what you were talking about.
As far as I understand, most of these companies that sell underpowered devices like this like to over estimate power delivery by using clever marketing. You'll never get them to admit it.
It's kinda like this little "home theater in a box" unit my brother in law bought a few years ago that claimed it was a 7.1 channel surround system, however when he unboxed it, it only had stereo left and right inputs, no digital input, no optic, nothing. Just left and right. Oh, but it had 7 speaker jacks!
Curious to know what sort of foolishness they were trying to do, we opened the unit only to discover that it had plastic-coated cement blocks in it to make it heavier and appear more valuable, what little room was left over was paper phenolic circuit boards covered in absolute junk and a toroid power transformer that made the one in my pre-amp look like a substation.
The market is flooded with these types of things. My guess is that if you keep measuring and testing inexpensive, mass produced stuff like this, you'll probably keep yourself busy for a lifetime sending them back.
I just read an article about powering air conditioners on sound waves!!
It's true....we've discovered the solution to the global energy crisis! Who knew?
Well the real problem I am trying to solve is the power draw. I need to design the (solar) power supply for all of this stuff.
So it is obviously not as simple as using the manufacturer specs and the support monkeys in both cases keep telling me I don't know what a Watt is.
You are right- I am going to waste a ridiculous amount of time on this if I persist in believing everything I read.
Just to clarify though:
Watt units are not different when discussing electrical power and audio power, the actual measure is just arrived at by different means.
The First Law of Thermodynamics remains true even in audio and even though 2 support technicians have told me it is not the same.
It's true....we've discovered the solution to the global energy crisis! Who knew?
Well the real problem I am trying to solve is the power draw. I need to design the (solar) power supply for all of this stuff.
So it is obviously not as simple as using the manufacturer specs and the support monkeys in both cases keep telling me I don't know what a Watt is.
You are right- I am going to waste a ridiculous amount of time on this if I persist in believing everything I read.
Just to clarify though:
Watt units are not different when discussing electrical power and audio power, the actual measure is just arrived at by different means.
The First Law of Thermodynamics remains true even in audio and even though 2 support technicians have told me it is not the same.
Righto. It might be easier to see how much power these things actually require if you had a kill-a-watt, but it's far more likely that they won't lie about current draw, only output.
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