Power Output vs Power Consumption (Soundbar)

Jun 7, 2018
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What is the difference between Power Output (reference) vs Power Consumption? I am eyeing a soundbar that lists Power Output (reference) of 330W (105W each channel for the soundbar, and 120W for the subwoofer). However power consumption is only 40W and 30W respectively per the manual. The Power Output (reference) is also per the manual. The soundbar is the Sony CT780.

I am purchasing an AVR (auto voltage regulator) for this system as its voltage is 120V and I intend to use this in a 220V country (said AVR has 110V output, which should work). Thank you!!
 
Solution
It's called Massaging figures. WRMS is the true measure of power.
Power consumption with a perfect 100% in/out ratio would mean that the speakers would be 40/30W.
Alas,
Class A amplifier is about 25% efficient - great sound
Class AB apmplifier is about 50% efficient - OK sound
Class B amplifier is about 75% efficienct - acceptable

The other problem you have with 110/220 is the Frequency of 60hz and 50hz.
Most cheap adaptors won't change the frequency and you may run into problems with this.

One more thing to add, power also have a THD - Total Harmonic Distortion - this is VITAL to power of amplifiers. This number is special. 1% is "standard" if you can say there is a standard.

Good amps would give a 0.1% distortion... how is this...
Here's the deal....there is no way that the power consumption can be less than the power output.

SO....my best guess at what they are doing is....perhaps they are referencing "idle power consumption" or something like that.

If you send a link to the manual....maybe I can clarify more.
 
Jun 7, 2018
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the manual can be found here, "Operating Instructions":
https://esupport.sony.com/US/p/model-home.pl?mdl=HTCT780&LOC=3#/manualsTab

page 37 onwards.

Thanks!!
 
Jun 7, 2018
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So in that case, power consumption will never exceed 70W at any given time this soundbar is in use right? (And consequently, a 250W AVR should be safe - as I've been reading that 3x the power consumption is recommended for AVRs, e.g., 3 x 70W = 210W)

Also, what then is the 330W power output reference Sony is quoting for this soundbar? Is this purely a marketing ploy? What is this number called and how is it related to power consumption?

Thanks!!
 
Power output is the amount of wattage sent to the speakers.
Power consumption is the amount of wattage that the soundbar draws from the AC outlet it's connected to.
In soundbars and other gear the output power is usually a fantasy It can NEVER be higher than the power consumption which varies with the volume. Since there are always losses and other power draws in the soundbar the power output can be at most 80-90% of the power consumption and as low as 20-30% in some cases..
Many countries have standards for how much power a device consumes when in standby but not in operation.
 
Jun 7, 2018
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Hi there - thanks for this. In this case, the actual power consumption will never exceed 70W power consumption quoted at any given time right? Would you have any idea as to where the "fantasy" 330W power output quoted is based on? It just seems a bit too misleading to quote a total power output of 330W, where in fact the power consumption is only a mere 70W. If I go through other manuals of Sony soundbars, this seems to be the trend.
 

SuperGiachi123

Estimable
May 27, 2015
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That's quite usual for audio equipment: power output sells, even if it isn't anywhere near being real. That soundbar will take 20-30w at best, 210W are a massive overestimate. And obiouvsly the amp's continuous output power is always less than the input power(amps usually output 50-65% of the power they use if theyre class AB ar 90+% if they're class D, but anything over 100 is against the laws of physics!).
 
Jun 7, 2018
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Thanks for all your help on this - much appreciated!!
 
Jun 7, 2018
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Thanks for your response. I'm actually amazed at how companies can get away with quoting these inflated power output figures. I wonder where these figures are based on as they are way above power consumption.
 
In the US receivers and amplifiers are rated according to a Federal Trade Commission standard which requires the unit be run at the level that creates the most heat and stress for one hour before the unit is measured. The spec is presented in a uniform manner so it''s easy to make comparisons.
It's not a perfect system as it doesn't take into account the ability to drive real life speakers that aren't pure resistive loads. AV receivers often produce far less power when all the channels are being used hard since they share a single power supply. That's why a quality separate power amp can sound louder than a higher rated receiver.
Other products like car stereo, HTS, powered speakers, subwoofers and others don't have to comply with this standard so they can rate power for very very very short peaks into very low impedance loads. They can also just make up a number and let you prove them wrong. Marketing is more important than reality.
 
Jun 7, 2018
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Thank you for the comprehensive overview! This makes it clearer now - very much appreciated.
 

ElectrO_90

Commendable
Jun 21, 2016
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It's called Massaging figures. WRMS is the true measure of power.
Power consumption with a perfect 100% in/out ratio would mean that the speakers would be 40/30W.
Alas,
Class A amplifier is about 25% efficient - great sound
Class AB apmplifier is about 50% efficient - OK sound
Class B amplifier is about 75% efficienct - acceptable

The other problem you have with 110/220 is the Frequency of 60hz and 50hz.
Most cheap adaptors won't change the frequency and you may run into problems with this.

One more thing to add, power also have a THD - Total Harmonic Distortion - this is VITAL to power of amplifiers. This number is special. 1% is "standard" if you can say there is a standard.

Good amps would give a 0.1% distortion... how is this relevant?

If I measure my amplifier at 50watts @ 0.1% distortion it would sound great
If I measure my amplifier at 100 watts @ 1% distortion it would still sound very good
If I measure my amplifier at 300 watts @ 10% distortion it would sound terrible.
Sadly, people measure at the 10% distortion - just to make their amplifiers sound more powerful than they are.
 
Solution
Jun 7, 2018
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Thank you for the added information. I am learning a lot from all these details I never bothered looking at before!