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ncdrawl
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Who needs 1kW ???
andy_c
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Re: Who needs 1kW ???

Interesting. Horizontal cooling fins? I guess it must have fans. Also, think how they'd have to measure the output power even into 4 Ohms (2 kW). Assuming a U.S. electrical system having 120VRMS and 20ARMS, that's 2400W max from a 20A circuit. The efficiency of a class AB amp is such that it will take more than 2400W AC in to get 2000W out of the amp. This means it would pop a 20A breaker trying to put out 2000W into 4 Ohms. So you'd have to run it off 240V, 20A to be able to measure this, assuming continuous power. And 4kW continuous into 2 Ohms? Can't be. That would pop a 20A breaker even if it were connected to 240V. If it were class D, it might squeak by.

Jan Vigne
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Re: Who needs 1kW ???

So you think the amp is driving the full 4k watts all the time?

Frank S
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Re: Who needs 1kW ???


Quote:
So you think the amp is driving the full 4k watts all the time?

Of course he doesn't think that. Try reading his post again.

SAS Audio
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Re: Who needs 1kW ???


Quote:

Quote:
So you think the amp is driving the full 4k watts all the time?

Of course he doesn't think that. Try reading his post again.

Play a bass note for long and it will pop the 20 amp breaker with 120vac, 4 ohm load at 2000 watts rms output, depending upon the actual average power consumed. Or a continuous sine wave doing maximum measurements. Of course normal music is very transient in nature so clipping would occur long before the RMS or average output power level reached 2000 watts output.

Amp might sound good with some extemely low efficiency speakers at high volumes, hard to say until tested.

dbowker
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Re: Who needs 1kW ???

Well, I'm sure anyone REALLY needs 1KW, but there are those that would disagree. Look at almost any old post by former member DUP and he'd say 1KW is for STARTERS! I think he had something like 4KW maybe- something crazy like that. A few members heard his setup and claimed that, at least at reproducing realistic concert impact, his rig was pretty amazing. Still...

Jan Vigne
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Re: Who needs 1kW ???


Quote:

Of course he doesn't think that. Try reading his post again.

Since you know what he thinks, why don't you explain it?

What sort of sensitivity in the speakers will require 4k watts at 2 Ohms for what frequency? I can't think of a speaker that has that sort of impedance/sensitivity combination.

So what produces that type of signal? What's the duration of that signal? Circuit breakers deal with time.

andy_c
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Re: Who needs 1kW ???


Quote:
Of course he doesn't think that. Try reading his post again.

Exactly. I'm talking about what happens when it's tested for continuous power as John would do in his measurements. If they're claiming a certain output power and it can't do so with the normal conditions of continuous power, they need to specify the conditions (e.g. 10ms or less).

The 2 Ohm tests that John does are brutal. Watch the "product of the year" go up in smoke! LOL!

JSBach
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Re: Who needs 1kW ???


Quote:
Christ Almighty

http://www.musicalfidelity.com/products/titan/index.html


Nobody 'needs' that amount of power but some may benefit. I once thought that mega-power amps were mere status symbols for people who wanted to annoy hell out of their neighbors with inefficient speakers. Having lived with a pair of Musical Fidelity 550K Superchargers for a while I was amazed at the improvement they provide boosting a 35W class A amp while playing at low volume. The question I was left with is this. Was it the massive reserves of power that made these things so effortlessly convincing at low levels or something else in the circuitry? I've heard other high powered amps that didn't manage this trick sounding dead at lower volumes.
More important to me, and why I've switched to a Boulder integrated with a mere 300 or so watts, is the efficiency such power is produced with and the power consumption at idle. This risks introducing the topic of global warming but considering the number of mindless rednecks posting here who deny the reality of GW I'm not going to discuss that.
I'm even eyeing off a pair of Nuforce power amps to assuage my 'green guilt' but I'm told that I'd have trouble running my electrostatics with them due to that stats earthing arrangements. I'm looking into it though as my stats earthing arrangements were modified to prevent my Boulder amp from self immolating.
I don't have the slightest grasp of the technological aspects of all this though.
OOOPS --- Sorry, he's wandered way off topic again. Silly old git.

SAS Audio
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Re: Who needs 1kW ???


Quote:

Quote:
Christ Almighty

http://www.musicalfidelity.com/products/titan/index.html


Nobody 'needs' that amount of power but some may benefit. I once thought that mega-power amps were mere status symbols for people who wanted to annoy hell out of their neighbors with inefficient speakers. Having lived with a pair of Musical Fidelity 550K Superchargers for a while I was amazed at the improvement they provide boosting a 35W class A amp while playing at low volume. The question I was left with is this. Was it the massive reserves of power that made these things so effortlessly convincing at low levels or something else in the circuitry? I've heard other high powered amps that didn't manage this trick sounding dead at lower volumes.
More important to me, and why I've switched to a Boulder integrated with a mere 300 or so watts, is the efficiency such power is produced with and the power consumption at idle. This risks introducing the topic of global warming but considering the number of mindless rednecks posting here who deny the reality of GW I'm not going to discuss that.
I'm even eyeing off a pair of Nuforce power amps to assuage my 'green guilt' but I'm told that I'd have trouble running my electrostatics with them due to that stats earthing arrangements. I'm looking into it though as my stats earthing arrangements were modified to prevent my Boulder amp from self immolating.
I don't have the slightest grasp of the technological aspects of all this though.
OOOPS --- Sorry, he's wandered way off topic again. Silly old git.

Unless one comes close to or is clipping, almost all the difference is the circuitry/design. I have checked into alot of different designs that measure the same, but sound quite different. And simply changing parts in the same design will also cause a difference.

Jan, I believe Apogee is one brand that really "sucks" the power. I believe they also dive to as low as 1 ohm impedance if I am not mistaken.

Take care.

Jan Vigne
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Re: Who needs 1kW ???


Quote:
Jan, I believe Apogee is one brand that really "sucks" the power. I believe they also dive to as low as 1 ohm impedance if I am not mistaken.

Undoudbetly, there are a few speakers from the c-r-r-a-a-a-z-e-e-y '80-90's that refuse to die even after killing off a few amplifiers along the way. But aside from the handful of Infinity's and Apogee's that dipped down to or beneath 1 Ohm there aren't many speakers that duplicate that bit of stupidity. My opinion of both speakers was the owner got what they deserved so they need to live with their choices.

However, show the Apogee's the sort of signal that requires 4k watts and it will either go, "Huh? You've got to be kidding!", or, "Goodbye!"

So, I'm still asking, what sort of signal into what sort of load could actually require 4k watts long enough to blow a circuit breaker?

Frank S
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Re: Who needs 1kW ???


Quote:

Since you know what he thinks, why don't you explain it?

Nothing to explain. You just misunderstood what he was saying, no worries. If you read it again, you'll probably understand it too.

Buddha
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Re: Who needs 1kW ???


Quote:

Quote:

Quote:
So you think the amp is driving the full 4k watts all the time?

Of course he doesn't think that. Try reading his post again.

Play a bass note for long and it will pop the 20 amp breaker with 120vac, 4 ohm load at 2000 watts rms output, depending upon the actual average power consumed. Or a continuous sine wave doing maximum measurements. Of course normal music is very transient in nature so clipping would occur long before the RMS or average output power level reached 2000 watts output.

Amp might sound good with some extemely low efficiency speakers at high volumes, hard to say until tested.

"Hard to say until tested." That's what Ethan would say!

How about, "Hard to say until listened to?"

(Goofing off, no flame content, amigo.)

Pete B
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Re: Who needs 1kW ???

I've been to a few Krell demos at the D'Agostino's home and I believe Dan mentioned that some of their stereo amps at one point had two line cords, not positive but that's what I remember. The amps used for the demo were wired for 220 V with dedicated circuits for each amp, IIRC. This was in the US of course making the 220 V outlets unusual for a home sound system.

Bob Cordell has done demos showing how high the peak power requirements can be with reasonable speakers and only moderately loud listening levels. I'll look for some documentation about this with qantitative numbers rather than try to go from memory here.

Some legendary mastering engineers have commented about how 1 to 2 KW amps sound different, effortless. I would guess because they never clip or have output protection circuitry trigger.

gkc
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Re: Who needs 1kW ???

Amen, Buddha. If the amps that are hooked up to your speakers don't have enough power to drive them, you'll hear it, and pronto. You won't need a test bench when the amps crap out. Your ears will notice a long time before the oscilloscope does.

Sensitive, efficient, and otherwise easy-to-drive speakers offer far more varied options, in terms of the amplification you will eventually feel is most compatible with your system, than do the difficult-to-drive models. But, you may like the sound of the latter better, and you may simply have to spend more money for the mega-watts required to drive these types of speakers.

If one's speakers are difficult to drive, the "sense of overall ease" offered by the mega-watt amplifiers out there today (sound quality assumed to be a given), as mentioned by the previous poster, can be immediately obvious. And, of course, don't forget the room. Big rooms need big power.

Machines don't monitor this selection process very well. As Buddha notes, sooner or later you just have to sit down and listen for what sounds best to you.

andy_c
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Re: Who needs 1kW ???


Quote:
Bob Cordell has done demos showing how high the peak power requirements can be with reasonable speakers and only moderately loud listening levels. I'll look for some documentation about this with qantitative numbers rather than try to go from memory here.

Hi Pete,

I was there at Bob's 2006 RMAF demo where he showed this. Average power for rather loud listening levels was 1-2W (really measured speaker RMS voltage using a true RMS voltage detector chip, with power normalized to 8 Ohms). The most extreme peak power was about 200W on a Rickie Lee Jones track. The PDF file describing all this is here.

So of course the peak-to-average power of music is such that high continuous power is almost never needed. But what I was getting at is amplifier power ratings. The standard is continuous power by tradition. So if a vendor is specifying their amp in some other way, they need to spell out what that is.

KBK
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Re: Who needs 1kW ???

we always used 30A/120VAC dedicated 'home run' lines going to dedicated 200A panels when installing in bars to keep failures to a minimum, to keep hum down, and safety up.

For a 750w/pc pro power amp that may be in mono to run a double 18" JBL sub box, this is a requirement, not an option.

This is/was all about goth, reggae, or Ska, whatever, done at about 115db average -all night long. considerably different than a home situation. At least in my personal case. Right now, I'm using a 60w/pc power amp, which is lucky to hit 3 watts most of the time.

SAS Audio
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Re: Who needs 1kW ???


Quote:
"Hard to say until tested." That's what Ethan would say!

How about, "Hard to say until listened to?"

I meant to say listened too as a final test. Sorry about that Buddha, and thanks for bringing that to my attention.

Take care.

ethanwiner
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Re: Who needs 1kW ???


Quote:
Look at almost any old post by former member DUP and he'd say 1KW is for STARTERS! I think he had something like 4KW maybe- something crazy like that.


Not crazy at all. I have just over 1 KW, and my friend Mark Weiss has something like 15 KW:

http://www.basspig.com/

Hey, do you want slam or do you want wimp?

--Ethan

dcstep
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Re: Who needs 1kW ???

I've got 1kW into 4ohms with my Rowland Continuum 500. (The nominal load of my Vienna Acoustic speakers is 4ohms). The combination of watts and high damping factors help certain amps control the drivers (particularly the woofers) of certain speakers. You don't buy based on power alone, but it can be an important component to consider, particularly with some dynamic speakers.

Dave

commsysman
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Re: Who needs 1kW ???

The real power demand is for reproducing organ pedal notes, etc.; stuff below 50 HZ.

I think that most people can get all the sound they want with a 120-200W main amplifier, IF they use a self-powered subwoofer for that really low stuff.

ferenc_k
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Re: Who needs 1kW ???

I was using an Audio Note Kageki 6W amp with an Avantgarde Trio for more than 8 years. Since I changed to an 1250W@4 ohm pro studio amp and an 98 dB/w/m pro speaker, I got an effortlessness, ease that my former system could not match at all. Even if the level is very quiet. Very entertainig with no emotion missed.

ROLO46
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Re: Who needs 1kW ???

You need 1kw to reproduce a Steinway D
I have .9kw with 3 Meridian DSP 6Ks in Trifield
This is not excessive

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