Power hungry speakers

[aarond]

<font color='#000000'>if the max draw from the wall is 500 watts can you tell me how you can turn 500 watts into 770 do they sprinkle magic fairy dust on it</font>

 

[zumbo]

<font color='#000000'>Uh, a amp!</font>

 

[zumbo]

<font color='#000000'>With your way of looking at things, a 2400 &amp; 1400 both output 500watts. You just pay a lot more for the 2400 because it has a larger number!

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[zumbo]

<font color='#000000'>nm2285 is looking for advice. If you do not have a clue, please do not confuse a person seeking logical advice!</font>

 

[annunaki]

<font color='#000000'>THe power spec is useless for one reason. It DOES NOT STATE ALL CHANNELS DRIVEN SIMULTANEOUSLY. By the way, If an amplifier was capable of driving 165 X 7 simultaneously, and being a class A/B amplifier (figuring 55% efficency), one would be looking at 1,674.75 watts (13.96 amperes at 120volts) of current draw from your wall outlet. This CANNOT be argued as it is subject to the laws of physics and or Ohm. At 110 per channel you are looking at 1116.5 watts of current draw (9,40 amperes at 120 volts). These above numbers are what the draw would be from the outlet, if it were capable of that kind of power. The rest of the specs on that amplifier should not vary much. Doubt it all you want but it is the truth. When they take those power specs they only drive one or two channels, making it pretty easy on the power supply.</font>

 

[zumbo]

<font color='#000000'>Does this not mean simultaneous?

Minimum RMS Output Power (8 ohms, 20-20,000 Hz 0,04% THD, FTC): 110W x 7(Total 770W )</font>

 

[zumbo]

<font color='#000000'>The H/K states MAX power of 70watts x 7.

The Yamaha states MIN power of 110watts x 7.</font>

 

[annunaki]

<font color='#000000'>If he is looking for advice he should listen up. If an amplifier draws 500 watts from a 120 volt outlet you have 4.16 amperes of current draw. Amplifiers cannot make any more power from the 500 watts. IT TAKES POWER TO MAKE POWER. Most home amplifiers are Class A/B which average about 55% efficency. Meaning that of that 120 volts, 55% is turned into amplifier power and the other 45% is wasted in heat due to the amplifier design. If the power supply can only handle or draw 500 watts maximum the MAXIMUM POWER IT COULD PRODUCE WOULD BE (due tho the 55% efficency of the design) 275 WATTS. If two power supplys are the same and the amplifier design is different, (with a higher efficency) say like full range class D which is around 75% efficent. One could get 375 watts of power from the same supply. &nbsp;If Yahmaha can generate 770 watts rms (110 x 7) from only 500 (4.16 amperes at 120 volts) watts of current draw, I am buying stock because they just solved all of the worlds energy problems.

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[aarond]

<font color='#000000'>zumbo you can not feed your speakers more power than you are getting from the wall. its always going to be less. apparent power (what the power co. bills you for) is going to equal the output stage of the amplifier divided by the efficiency of the amp multiplied by the power factor. so lets say your 770 watt amp had an efficiency as high as 88% and a power factor as high as 0.98 It would take 893 watts of apparent power for the output of the amp to reach 770 watts
770/0.88 * 0.98</font>

 

[zumbo]

<font color='#000000'>Oh. So It does not matter what amp or receiver you buy because it can only produce a percentage of what you get from the wall outlet!

 You guys are killing me!

Man, I could have saved all kinda money!

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[annunaki]

<font color='#000000'>If it doesn't state simultaneous, it most likely isn't, and your guess is as good as mine. RMS means, root mean squared. It is the same as continuous.
In the piece of Harman Kardon literature in front of me, nowhere does it state max watts x 7. Yahmaha is just stating that that is the minimum amout of power you will get when running that receiver the same way that they tested it, in two channel mode. Call tech support and ask them how it is rated.</font>

 

[Guest]

<font color='#000000'>Sorry to say ZUMBO, but they are correct. Also, I doubt it very much that the Yammy actually puts out the power it says it does in multichannel. All the reviews I have read show that Yammy as well as Denon as well as a host of others never do put out the power they say they do in multi channel...but this is not true with HK or Marants...they do put out the power they bost...If I have time I'l find some of those reviews and post them here.

frenchcmon</font>

 

[zumbo]

<font color='#000000'>Max Surround Pwr
&nbsp;20Hz - 20kHz: Main - 0.07% THD, 70W. Center - 0.07% THD, 70W. Surround - 0.07% THD, 70W. Surround Back - 0.07% THD, 70W.

Straight from the spec. sheet of the avr 525</font>

 

[annunaki]

<font color='#000000'>Zumbo,
You had it exactly right. Take an electronics course. They will tell you that and more. All a receiver is doing is converting the wall outlet's power, 120 volts, into a wattage capable of being manipulated by the input signal from a source. In turn, it uses some of that power to perform the operation, thus it cannot directly convert all of that power to usable wattage. The power used to perform these operations is usually disapaited in heat. The hotter an amplifier is (usually, not always) the more power it wastes in heat. Especially at low to no volume.</font>

 

[zumbo]

<font color='#000000'>And, if your statement is true about 2-channel mode, then that means the H/K is 85 x 2 and the Yamaha is 110 x 2. Why is this so hard to understand.</font>

 

[annunaki]

<font color='#000000'>I stand corrected on the &quot;max watts&quot;. That must be how they stated it on the older stuff. I can assure you, however, that it is indeed RMS power.</font>

 

[Guest]

<font color='#000000'>Ok ZUMBO...heres the link...although it not your model number it tipicle of Yammy...The Yammy should be the last review.


http://www.homecinemachoice.com/testbench/index.html</font>

 

[zumbo]

<font color='#000000'>That is not US specs. useless to me.</font>

 

[annunaki]

<font color='#000000'>Yes, in two channel mode those numbers are pretty accurate. If the H/K is anything like some of the ones I have seen in reviews it will probably spec out around 105 or so per channel. The Yamaha will also likely show up in the 125 range. Here is the key though, that difference is INAUDIBLE in terms of sound pressure level. One other thing, seeing as though the H/K is rated with all channels driven simultaneously, and the Yahmaha is rated with two channels driven. The H/K should have more dynamic headroom available than the Yahmaha.</font>

 

[zumbo]

<font color='#000000'>But, how is this less? Yamaha's rating is 110W per channel. We measured 117W RMS

This is straight from your link!(frenchmon)</font>