Power hungry speakers

[annunaki]

<font color='#000000'>You know what sucks though? Now I do dot have a whole lot to look forward too when I frequent this forum.

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[brochini]

<font color='#000000'>Hk 330, 430, 630 or NAD 753 or 773. Hope Nad's power rating on all channel driven is true. Annunaki/Ross if 7.1 is my choice what is good, else if 6.1 is Nad 753 the best choice. &nbsp;Zumbo, if I follow your route Nad T163 tuner preamp is my choice but my Carver though 5.1 is absent from &nbsp;new decoders, only pro-logic and sonic holography. Ross, my system is satellite/sub type using front bigger Canton satellites, Solid surround and a huge velodyne sub. &nbsp;Center is temporarily a Cambridge MC300. Now with Onkyo 701, Nora (Come Fly with Me) piano and vocal is verly lifelike and clean sound. A PSB Image 4T will have a new version at $430/pair next month. If I buy these fronts, then the only choice is to go 7.1 receiver. I think floor standing ear level is far better than sats type.

Folks, bottom line, &nbsp;do you think I should just keep the Onkyo, stick to 6.1 and save some bucks.

Thanks,

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[Rip Van Woofer]

<font color='#000000'>Wow! How did I miss this great fight...er, discussion?!? Very illuminating, indeed.

Geez, it seems that in some ways we're back to the bad old days of mfr's playing games with power ratings. Back in the 70's the gov't finally clamped down and ruled that RMS was the standard to be applied, and all seemed well. But now, judging from this exchange, multichannel and good old capitalist ingenuity appear to have opened new loopholes, i.e., are the ratings with all channels driven?

One of the things I like about The Audio Critic magazine is that they do a test called a PowerCube, the gear and software for which they got from Europe, that measures amp output into not only varying impedance loads from 1 ohm (!) up, but also into varying degrees of resistive and reactive loads (I'm fuzzy on the concept of &quot;reactive&quot; but I guess it's a factor with speakers too.). It appears to give a very good indication of an amp's overall quality, and especially of its ability to drive difficult loads like low or widely varying impedance, as well as extremes of resistance and reactance. They claim to be the only publication in North America using the test.

They're also big on noting an amp's output in volts and amps as well as watts. As pointed out earlier here, how much current an amp can deliver or &quot;swing&quot; is at least as important as its output in watts, and a good indicator of a robustly designed power supply, as are good PowerCube results.

I'd sometimes thought of suggesting it to Gene, Hawke and the boys so...have you guys considered adding it to your lab? Might be a real service and a coup for Audioholics to be the only Website in America (maybe the world!) using it.</font>

 

[annunaki]

<font color='#000000'>Rip,
The Power Cube is interesting as it shows power output at a resistive impedece, meaning one that is held constant. The neat thing is that it shows power output into a reactive load, at varying impedences (like a speaker exhibits), and through varying different degrees (angles) of phase. Viewing a power cubes measurements quite often shows how competant an amplifiers power supply is. If used for home they would have to state when an amplifiers low impedence and/or current limiting circuitry kicked in.</font>

 

[Guest]

<font color='#000000'>This whole &quot;power cube&quot; thingy sounds pretty cool!

Since this thread is still alive, I'll respond to something I didn't to earlier on.

Annauki,
No, I do not believe an amp can put out more than it can take in. &nbsp;However, you must treat the rated &quot;power consumption&quot; the same as you treat the other manufacturer provided specs. &nbsp;The UL listed power consumption is there for legal reasons alone, not as an indicator of the amp's performance. &nbsp;Just like the supposed continuous 7-channel output (as the manufacturer states) of receivers like the denon or yamaha, the ACTUAL power consumption is not what the manufacturer provides. &nbsp;The only way to find out what the ACTUAL power intake and output of a unit is, would be extensive lab testing with the necessary equipment. &nbsp;

So basically, I don't disagree with your logic on what an amp can do with the power it draws from the wall, I just disagree in your calculation methods in the performance of various amplifiers via simplified formulas.

best,

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[annunaki]

<font color='#000000'>Ross,
I will agree that the power consumption spec may not be exact from the manufacturers, however, it is much closer than their wattage output ratings. From most of the companies tech support people I have spoken with, over the phone, power consumption specs are taken with all channels driven simultaneously into 8 ohms to rated distortion. The power consumtion specs will vary, or increase if the distortion level is increased to say .1% or 1%. This won't result in an audible difference in power. In fact you are probably only looking at a possible 5-15 watt increase per channel, depending upon the receiver.

Brochini,
The NAD T753 will definitely offer greater output all channels driven simultaneously, as well as increased dynamics. The power supply in that receiver is just huge! It is up to you how you want to upgrade. It is your money. If you can use a separate amplifier and/or in conjunction with a preamp, I would suggest that route.</font>

 

[annunaki]

<font color='#000000'>Ross,
One other thing, I never stated that the formula would give you ACTUAL wattage. It will get you in the neighborhood of what the supply is capable of, give or take a few percent. Also, these companies are not going to fudge the current consumption figures too much. Especially if they are there for LEAGAL purposes. Manufacturers look to cover their behinds in every way possible. I highly doubt they would let something that could possibly have large legal ramifications (a fire resulting in death, highly doubtful, yet possible) slip through the cracks</font>

 

[Guest]

<font color='#000000'>&quot;however, it is much closer than their wattage output ratings.&quot;

Unfortunately, I do not find any difference between the ratings of these two measurements. &nbsp;Both the wattage ratings and the power consumption are simply a means to satisfy the lawyers. &nbsp;The supposed power consumption even more so due to the little UL sticker close by...

&quot;power consumption specs are taken with all channels driven simultaneously into 8 ohms to rated distortion.&quot;

You have to remember, most people look at an amp or receiver's specs and think it is stating 5,6, or 7 channel performance.

&quot;This won't result in an audible difference in power. In fact you are probably only looking at a possible 5-15 watt increase per channel, depending upon the receiver.&quot;

This is not true. &nbsp;A good analogy would be the mileage estimates on a car's window sticker. &nbsp;When you're buying a new car, the mileage estimates on the sticker have almost no correlation whatsoever to the actual horsepower of the engine... &nbsp;Just like those tricky little wattage specs, things are not always what they seem... &nbsp;A unit may have a 500 watt power consumption rating, but under what conditions was this number was derived???

best,</font>

 

[annunaki]

<font color='#000000'>Ross,
That is what I was saying about calling manufacturers and finding out how the power consumption specs were derived. I did call some manufacturers, all that I called, (H/K, Onkyo, NAD, and Denon) stated they were all channels driven simultaneously to rated thd. Apparently, they have to be a bit more honest in this respect as opposed to wattage output ratings.
Please tell me you are not serious, in thinking you can hear a 5-15 watt difference from an amplifier when it is already, at say, 50 watts rms per channel. Remember, you must double power output just to see a 3db increase on paper (maximum real world increases are in the 2db-2.5db increase, the most noticeable difference here would be with dynamics and not in spl). 3db to the ear is JUST noticeable with music. Most people do not and/or barely even notice it.</font>

 

[Guest]

<font color='#000000'>If you believe what the manufacturer spoon feeds you...

&quot;That is what I was saying about calling manufacturers and finding out how the power consumption specs were derived&quot;

Then you should believe this as well...

&quot;This receiver's high-end XXXXXX construction and circuitry includes an innovative Digital Drive amplifier that delivers a whopping 120 full-bandwidth-rated watts x 7 channels of home theater power.&quot;

and this...

&quot;170 watts x 7 into 8 ohms (20-20,000 Hz) at 0.6% THD&quot;

&quot;Please tell me you are not serious, in thinking you can hear a 5-15 watt difference&quot;

Where did this 5-15 watt calculation come from?

Unplug from the propoganda machine my friend!!!

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[annunaki]

<font color='#000000'>Most receivers and/or amplifiers increase around 5-15 watts in power output from say .07%thd to .1%-1% thd. Sorry, I should have explained it a little more. I will have more info tomorrow. I have to run.</font>

 

[Guest]

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best,</font>

 

[annunaki]

<font color='#000000'>I am still waiting on some info. I will keep you posted.

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[annunaki]

<font color='#000000'>Still waiting on info.

Probably won't have anything until at least monday. Sorry.</font>

 

[Ross]

<font color='#000000'>Its Friday! &nbsp;Kick back, relax and have a cold one on me!

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[annunaki]

<font color='#000000'>The guys at the UL office suck to get a hold of.

I will call my friend also. He has a master's degree in electrical engineering. He is building his own amplifier.

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