Amplifier power and efficient speakers, Is more power better?

mort · « **on:** 24 Nov 2009, 07:12 am »

"Once, Bob Carver visited a famous sound researcher who was attempting to recreate the "snip" of an ordinary pair of scissors. He used no less than TWENTY-FOUR 200-watt amplifiers for playback, yet when viewed on an oscilloscope it was apparent that the top of that instantaneous transient was being distorted. Believe it or not, he needed more power! It was evident that real-world sound occurs very quickly and requires far more power than ANY current amplifier could produce." and so forth came the m-1.5t equal in sonic quality on every level(according to Sterophiles entire edditing staff) to the Conrad Johnson premeir five, the unabashed flagship of amplifiers of that time, at a tenth of the price, upending the egos of all of the elitist audio snobs of the day. Once again is it nessesary to remind these foolish money wasting audio fools that expensive gear is still only on a par to gear costing multiple thosands of dollars less?

................................"I THINK THAT FALSE BELIEFS,
ESPECIALLY IN AUDIO, HAVE GIVEN
RISE TO SOME REALLY WILD DESIGNS.
FOR EXAMPLE, $25,000, 9 WATT AUDIO
AMPLIFIERS - YES, YOU READ THAT
RIGHT, 9 WATT. YOU WILL NEVER FIND ME
DESIGNING SUCH EQUIPMENT- I SIMPLY
DO NOT BELIEVE IN IT. HOWEVER, I LOVE
TO READ ABOUT SUCH DESIGNS AND I
LOVE TO THINK AND TALK ABOUT THEM.
I?M OVERJOYED THERE ARE PEOPLE IN
THIS WORLD WHO DO DESIGN AMPLIFIERS
LIKE THAT. IT?S PART OF WHAT MAKES
AUDIO SO MUCH FUN!"
C.T.O.
Sunfire
BOB CARVER................................. ....................................... ...........I also am interested in what people think of Blind testing.In these above mentiond trials and, countless others it has been found that different amplifiers in a simmilar power range provided they are bolth of reasonable quality one more expensive than another are indistiguishable to even the most precious of golden ears.

Imperial · « **Reply #1 on:** 25 Nov 2009, 12:17 am »

Well, first we must lay down some rules here...
When recording... the microphone records but a fraction of the released energy...
Then upon playback, we amplify it back up to the "sort of" same level.
Is it the same sound? No....

So is more power better? No, but it helps...

I'm gonna asume that blind testing is not what we will talk about here...
But go on over to: The Lab...

No, not allowed there either...

Oh wait, there is actually a forum for double blind testing, you can talk to the "inventor" of it... Ingvar Ohman there!!! www.faktiskt.se
Oh wait,they speek swedish... do you?

I have debated him there on his forum, you know when the war on sound raged...
That James Randi, Fremer and Pear Cable war and all that. Rather fun actually!

It subsided, the war... it went away...
You wish to go to war again? Learn Swedish.

Imp. You speak a my language... ? No, sorry...

Imperial · « **Reply #2 on:** 25 Nov 2009, 12:42 am »

But I do love esoteric designs!!!
Works of art and all that!

My favv amp cost $7092 pr/watt...
Imp. Top floor, bottom buzzer...

Niteshade · « **Reply #3 on:** 25 Nov 2009, 12:47 am »

Transient response and dynamic range are very important amplifier qualities. High power amps, if made properly, will enhance sound quality. I have a few recordings that I call amp killers. They WILL kill low wattage amps at low volumes. They will stringently test high power amps. Two words: Johnny Cash.

Johnny Cash is the equivalent to being stuck in a tar pit to many amps.

Imperial · « **Reply #4 on:** 25 Nov 2009, 01:29 am »

But, and don't think that I believe that I.Ohman isn't a great dude, because he is!
Ok. I regard this Swede among the top 5 amplifier "know it alls" on the planet.
He really is the equal to Carver or anybody really.

This is what he says about amps:
- An amp should have 100w. (Speakers he like is typically 86 to 94db sensitive...)
- Should be able to drive 3 ohm load all day.
- pass a DBBT test (in his rig no doubt...)
- If it is able to peak at 1000w that would be great...

He's got a thread on his "site" that has lasted for two years now, and it still rocks!!!
The tagline is: "What amplifier is the best?"
It's a vote actually, and it's been running for two years!!!
Those Swedes, they have patience...

The thread is about the inner workings of poweramps, methods, parts, measurements and stuff...
Right up your alley!
I'm gonna gonna link it to you Mort. Beg steal or borrow someone that speaks swedish and have him/her read it up for you, it really is a great thread!!!
http://www.faktiskt.se/modules.php?name=Forums&file=viewtopic&t=20221&start=0

The threads motif, is to educate the followers, in Ohmans way of seeing it. Interesting! But Alas, in "Bork bork..."

There you go!

Imp.

werd · « **Reply #5 on:** 25 Nov 2009, 01:53 am »

Quote from: mort on 24 Nov 2009, 07:12 am

"Once, Bob Carver visited a famous sound researcher who was attempting to recreate the "snip" of an ordinary pair of scissors. He used no less than TWENTY-FOUR 200-watt amplifiers for playback, yet when viewed on an oscilloscope it was apparent that the top of that instantaneous transient was being distorted. Believe it or not, he needed more power! It was evident that real-world sound occurs very quickly and requires far more power than ANY current amplifier could produce." and so forth came the m-1.5t equal in sonic quality on every level(according to Sterophiles entire edditing staff) to the Conrad Johnson premeir five, the unabashed flagship of amplifiers of that time, at a tenth of the price, upending the egos of all of the elitist audio snobs of the day. Once again is it nessesary to remind these foolish money wasting audio fools that expensive gear is still only on a par to gear costing multiple thosands of dollars less?

................................"I THINK THAT FALSE BELIEFS,
ESPECIALLY IN AUDIO, HAVE GIVEN
RISE TO SOME REALLY WILD DESIGNS.
FOR EXAMPLE, $25,000, 9 WATT AUDIO
AMPLIFIERS - YES, YOU READ THAT
RIGHT, 9 WATT. YOU WILL NEVER FIND ME
DESIGNING SUCH EQUIPMENT- I SIMPLY
DO NOT BELIEVE IN IT. HOWEVER, I LOVE
TO READ ABOUT SUCH DESIGNS AND I
LOVE TO THINK AND TALK ABOUT THEM.
I?M OVERJOYED THERE ARE PEOPLE IN
THIS WORLD WHO DO DESIGN AMPLIFIERS
LIKE THAT. IT?S PART OF WHAT MAKES
AUDIO SO MUCH FUN!"
C.T.O.
Sunfire
BOB CARVER................................. ....................................... ...........I also am interested in what people think of Blind testing.In these above mentiond trials and, countless others it has been found that different amplifiers in a simmilar power range provided they are bolth of reasonable quality one more expensive than another are indistiguishable to even the most precious of golden ears.

Hello

I owned that Carver amp and it sucked bad. The bass was terrible. Most recievers of that time period blew it away. Almost all Luxman destroyed it interms of bass and controlled treble. The M-1.0 was a better amp it sucked too.

Sorry

Imperial · « **Reply #6 on:** 25 Nov 2009, 03:15 am »

Quote from: Niteshade on 25 Nov 2009, 12:47 am

Transient response and dynamic range are very important amplifier qualities. High power amps, if made properly, will enhance sound quality. I have a few recordings that I call amp killers. They WILL kill low wattage amps at low volumes. They will stringently test high power amps. Two words: Johnny Cash.

Johnny Cash is the equivalent to being stuck in a tar pit to many amps.

She's mostly unknown but Dana Doidge has a crushing strong and tuneful voice:
http://www.myspace.com/danadoidge
Give this one acouple of more years and I think we've got us a new audiophile darling...
Awesome clarity and a narrow band harmonics to her voice. Unlike other operatic singers I think.

Then there is a Bulgarian Woman kalled Kapka Dimitrova. Talk about dynamic voice? Oh yeah...
Strongest operatic female I've er heard!!! She is not very young anymore, she must have been crazy
dynamic when she was, because what I've heard of her at older age is wild.

Imp.

smk · « **Reply #7 on:** 25 Nov 2009, 03:52 am »

Are you trying to reproduce test tones?

AmpDesigner333 · « **Reply #8 on:** 25 Nov 2009, 04:10 am »

Had to put in my 2 cents...

More power usually comes with a few compromises, such as zero-crossing distortion, transient distortion, and noise. We worked for decades to find a solution to these issues and think we've found it. Doing so is not cheap, but it doesn't need to be outrageously expensive either.

A quick word about zero crossing distortion... At low levels, high power Class-AB amps have real issues controlling a reactive load. Imagine driving a car where the middle 10 degrees or so of steering wheel rotation has no effect on the direction of the car.

Regarding noise, the more power output, the louder the same noise figure (dB) with respect to maximum power sounds. There's no magic, so you need really good SNR to sound good at low levels with high max power.

Another concern is peak output delivery. If you can put out 100A into 4 ohms momentarily (micro- or milli-seconds), this is equivalent to 40,000W! The path from the power supply to the speaker needs to be as direct as possible to provide clean peaks.

This is just touching on the subject, but hope it clears up a few issues that are commonly misunderstood. Thanks for reading it!

watercourse · « **Reply #9 on:** 25 Nov 2009, 05:21 am »

My two cents as well - I have relatively sensitive speakers (91db) that are said to mate well with lower power tube amps, in fact, designed for such amps.
High efficiency is a priority for me in these climate changing times. On my search for a Class D amp that mated well with these speakers, I first went from a 150 watt stereo amp to a 30 watt stereo amp which was voiced using my speakers.
However, I did not hear the real potential of these speakers until I mated them with an amp rated at >380 watts/channel. From low volume listening to volumes where I seriously worry about overdriving and damaging my speakers, it is the microdynamics, accurate tone, and finesse - rather than brute force - that is the most appreciable quality of this combo. I doubt that I ever push my amp even close to breaking a sweat, and probably will never need to.
The tube amp that I heard at the dealer demo driving these speakers were 40 watts/channel, so I doubt this setup would qualify for truly low power. That combo was intriguing, but well out of my price range ($11K for the amp). But was it better?
I'd have to hear in my own system, but at that price differential, it would have to be so much better that I would probably have remembered it as such. I don't.

lcrim · « **Reply #10 on:** 25 Nov 2009, 06:13 am »

This topic also drew my attention. I've been interested in high efficiency and single driver speakers for a number of years and now use both flea amps and bought a higher power SS amp this summer, the Dayens Ampino.
The Ampino is only 25 watts output @ 8 ohms but this level of power is dramatically higher than the 2 to 5 watts I'm used to listening to. The difference in my experience is that this particular SS amp compared to my Miniwatt and Decware amps using the same speakers is an ability to portray complex music in a cleaner and quicker fashion at the expense of some loss in tonal color. This is most noticeable in the treble'
I hasten to add that I really like the lower power amps for what they do with enriching the presentation w/o the SET oversaturation issues.

Russell Dawkins · « **Reply #11 on:** 25 Nov 2009, 08:35 am »

Quote from: AmpDesigner333 on 25 Nov 2009, 04:10 am

A quick word about zero crossing distortion... At low levels, high power Class-AB amps have real issues controlling a reactive load. Imagine driving a car where the middle 10 degrees or so of steering wheel rotation has no effect on the direction of the car.

Good analogy - reminds me of a '57 Chevy I had in '73, except it had at least 90 degrees of slack...

Among manufacturers Antony Michaelson of Musical Fidelity is the most frank and outspoken on the subject in my experience. A (very rough) summary of what he says is that for speakers of typical efficiency with any amplifier that measures under 200 watts per channel you are comparing clipping behaviour, since amplifiers are clipping a little most of the time when trying to play even moderately loudly.
You could read his paper on this on the MF site, but I just tried and could not access it. It might be a temporary server problem.

Big Red Machine · « **Reply #12 on:** 25 Nov 2009, 11:27 am »

It would seem that high power amps on high efficiency speakers is overkill on the surface. But I have got to tell you I am ecstatic with the total sound produced by 120 watt tube monos over 40 watts of tube power and 65 watts of SS on my 95 db speakers.

Sure, the topologies are different so not apples to apples, but having that 500 horsepower under the hood and just seems to drive the entire frequency range with authority. I never experienced deep, tuneful bass until these amps were plunked down.

What I find with any high powered amp, and let's mention Tommy's amps here, is that they are a beast with lightning quick reflexes that can snap any transient out with full authority and as mentioned, never break a sweat. I've always appreciated high powered amps for having reserves and even with these 95 db 3 ways, I appreciate the headroom even more. A lot of power is expended to recreate bass and while the amp is doing that it has to have enough left over to recreate the other frequencies.

BobRex · « **Reply #13 on:** 25 Nov 2009, 05:20 pm »

I've always had questions about Carver's little "test". The math just doesn't add up. I just measured the SPL of 2 different pairs of scissors at a distance of 6 inches. Both pair had peak measurements of 78dB. Let's call that the average signal strength. Assuming an average speaker sensitivity (86dB?), you need less than one watt to recreate the average signal. Now, given that Carver needed almost 5000 watts (or 37dB) to "capture" the full transient, that means that the transient generated 123dB (86+37) over the speaker load.

Here are the questions:

1) There is no low frequency content in a scissors transient, so most of the energy will be above 500Hz. What mid and treble transducers were available 30 years ago that could handle 5000 watts?
2) What were the criteria for Carver's measurements - distance from speakers, base level of the scissors transient, what speakers were used,how was the signal recorded (which in itself probably chopped off part of the transient),...
3) Is OSHA aware of the scissors danger? How many tailors and seamstresses have gone deaf from being exposed to these highly dangerous levels? Shouldn't we be calling our Congressmen?

When talking about the increases in "authority" you do want to be careful to compare apples to apples. Take a look ar Roy Gregory's report on the improvements when stepping up in the conrad-johnson line, from the LP70S to the LP140M, to the LP275M (HIFI+ issue 52 - "The Price of Power"). Gregory did report improved authority, better transients, and a slew of other improvements. So there is some real (as opposed to paper cutting) precedence to the idea.

Michaelson's ad paper (and the "system diagnostic tool" that he developed) is also questionable. He claims that for a system to be of "high quality" it must deliver clean peaks in excess of 106dB at the listening position. Which given the supposed peak to mean ratio of 20dB on most CDs, means that you have an average listening level of 85dB. That's at least 10dB louder than what I listen at, so I guess I'll never have a "high quality" system.

srb · « **Reply #14 on:** 25 Nov 2009, 05:36 pm »

Quote from: BobRex on 25 Nov 2009, 05:20 pm

Here are the questions:

Quote

1) There is no low frequency content in a scissors transient, so most of the energy will be above 500Hz. What mid and treble transducers were available 30 years ago that could handle 5000 watts?

Multiple transducer setups or large line arrays?

Quote

2) What were the criteria for Carver's measurements - distance from speakers, base level of the scissors transient, what speakers were used,how was the signal recorded (which in itself probably chopped off part of the transient),...

Only Bob Carver would be able to answer that one.

Quote

3) Is OSHA aware of the scissors danger? How many tailors and seamstresses have gone deaf from being exposed to these highly dangerous levels? Shouldn't we be calling our Congressmen?

That explains why everytime I ask my hair stylist a question, she says "What?"

Steve

Wayner · « **Reply #15 on:** 25 Nov 2009, 09:15 pm »

I have several times tried to record thunder. Realizing that the big Kaboom was impossible, I conccentrated on the more benign, calmer clappers. I really think it's the lack of amplifier (or for that matter, microphone) speed that inhibits the reproduction, not the power requirement (tho you must have enough power to reproduce the dynamic range. I'm sure most of you have been in your house when a tremendous thunder clap rattled everything in the house, including the house. What shear power, what energy, what spontaneity! I'm sorry, we can't even come close, not with a million watts.

To answer the blog's initial question, usually the more power, the better. IMHO.

Wayner aa

avahifi · « **Reply #16 on:** 25 Nov 2009, 09:24 pm »

I recall an article in Stereophile a while back. The editor had visited one of my clients who was running a set of Legacy Whisper speakers triamped with three Insight 500 power amps each bridged mono per channel. That is over 6000 watts of real power driving one pair of speakers.

The editor mentioned that when he went home to try his own system again, it sounded as if the notes were coming out and then falling face down on the floor in front of the speakers.

Regards,

Frank Van Alstine

werd · « **Reply #17 on:** 25 Nov 2009, 10:25 pm »

Quote from: Wayner on 25 Nov 2009, 09:15 pm

I have several times tried to record thunder. Realizing that the big Kaboom was impossible, I conccentrated on the more benign, calmer clappers. I really think it's the lack of amplifier (or for that matter, microphone) speed that inhibits the reproduction, not the power requirement (tho you must have enough power to reproduce the dynamic range. I'm sure most of you have been in your house when a tremendous thunder clap rattled everything in the house, including the house. What shear power, what energy, what spontaneity! I'm sorry, we can't even come close, not with a million watts.

To answer the blog's initial question, usually the more power, the better. IMHO.

Wayner aa

I bet Haarp can http://www.haarp.alaska.edu/

Russell Dawkins · « **Reply #18 on:** 25 Nov 2009, 10:38 pm »

It's been said before in the last couple of years, but I think it bears repeating - I think we may eventually discover that we are currently underestimating our actual dynamic needs for "high fidelity" by a factor of around 10.

Franks Van Alstine's story as well as reports of Earl Geddes' listening sessions underlines it, and I think this is behind the enthusiasm surrounding Bastanis and Emerald Physics.

werd · « **Reply #19 on:** 25 Nov 2009, 10:51 pm »

Quote from: Russell Dawkins on 25 Nov 2009, 10:38 pm

It's been said before in the last couple of years, but I think it bears repeating - I think we may eventually discover that we are currently underestimating our actual dynamic needs for "high fidelity" by a factor of around 10.

Franks Van Alstine's story as well as reports of Earl Geddes' listening sessions underlines it, and I think this is behind the enthusiasm surrounding Bastanis and Emerald Physics.

yes, i think it has to do with power retrieval/avail from the outlet than an audio component design issue.