Dolph: So you don't like science. Can you at least edit your post for grammar and spelling?

...but let's confined to the facts i mean, math and not theories!

Here's an example of a fact:

Question:
What is the equivalent output rating of a 200 Watt amplifier when specified in dBW?

Probably you don't know the formula to apply in that question....?! And there is no problem with that...but, when i don't know something, i simply ask.


Answer: P’=10log10(P/Reference), P’=10log10(200 W/1 W), P’=23 dBW.

You're new here at ST, and i understand this is a very subjective issue in certain "audio"(?) forums...but here at ST we always try to be very accurate about what sound's concern.

Here's another one concerning THD ( Total Harmonic Distortion ).

Question:
The output of a distortion analyzer is 2 mV for a nominal output of .775 volts. What is the THD spec?

Answer: THD = 2 mV/.775V = .258%.



Cool.

BTW, here's something about DB's:

Everything You Ever Wanted to Know About Decibels But Were Afraid to Ask

A nice weekend for you too, Dolph.

I am not a native like you.

I'm danish and therefor Danish, Swedish, Norwegian and German are more natural languages for me.

But your patronizing post is so infantile and unthoughtful that you should be very ashamed and you deserve to be spanked in your little bottom by those adults who failed to raise you properly.

"dolph"

That's very good of you to try to explain a mathematics/physics- moron like me.

But could you please, then, explain for me how Some e.g. 20 W amps play louder IRL on the same speakers as some other e.g. 150W amps.

You must the right wise person to explain this paradox.

And this is happening................it's not just fictitious thinking.

And by the way.................
I participate in more than 40 HiFi fora around the world and have been doing this exchanging knowledge and experience for as many years as the internet forum idea was started.

I wrote this in my first post here.

I am sorry that this forum was invissible to me until now.

My wife allowed me a few moments more on the Internet and getting back here with you enginious guys was my first thought.

"dolph"

Come on now, you can't take ANY criticism can you...

there is nothing wrong with criticism, as long as it isnt personal in nature.

which amps and speakers are you talking about? without knowing the specific equipment, there too many unknowns involved making it impossible to supply a rational answer.

I can't point out specific gear involved in this kind of situation.

I can tell you that this has not been a one time experience.
It has happened several times over the years in HiFi events or at showrooms at dealers here in DK.

I deliberately forget all gear not worth remenbering.
Why should one remember low-end gear.

Just explain this fairly general phenomenon.

"dolph"

theres your answer. no phenomenon here, it makes perfect sense now.

I'm not a RF amplifier expert but, i'm quite sure it'll have to do with the quality of the amp driver. A good example is the ADL5523 the designer choose or not to obtain a good relation between Internal Return Loss, Voltage Standing Wave Ratio and impedances_:

The VSWR is usually stated at an impedance of 50 ohms because most wireless systems operate at 50 ohms and antennas are designed to match this impedance as closely as possible. High values of voltage standing wave ratio can be harmful to the antenna, transmission line and of course have great impact in everything sound's related.
As you might know, impedance mismatches cause some of the transmitted energy to be reflected back to its source, which can also be expressed in terms of return loss (in dB).

The purpose of matching these impedances is to minimize wave reflection and/or to maximize the transfer of power between the system and the load.

...and, we're talking about very complexes impedances.... here's a link from Wiki:
http://en.wikipedia.org/wiki/VSWR

Stay tunned.

Thank you very much for the explenation.

However, does this count for discrete build amps, tube amps, tube amps with autoformers and OTL amps as well?
And would they respond similar or different on Z-loads?


And finaly; I'm glad to read in your answer about the complexity making the watt/power/dB discussion not that easy, after all, to put into mathematical definitions.

That makes our point of views, no matter what scientific foundation they represent, both approaching each other.

Enjoy whatever sunshine the day may bring you.

"dolph"

Of course every impedance (Z-load) matters for us to consider its effects on every system response. I mean the driver and load must be as closely matched as possible to acheive maximum power transfer. As a consequence of that, you want the output impedance of the amp to be as low as possible.
Typically you want the source to have a maximum of 1/10th the impedance of the driven device. With speakers you would want a maximum output impedance of 0.8ohms for a nominal 8 ohm speaker. Less is more in this case, and the lower the output impedance the better.

I start this topic just to point out in general the differences between watts and db’s and for this matter the mismatch between what our ears perceive (in DB’s) and how amplifiers are specified (in Watts).

Have a great Sunday.

Well.....................

I have to correct you guys.

I gave you the chance to correct yourselves in the way I asked the questions.

Transcendent and Atma-Sphere OTL amplifiers are more powerful in an 8 Ohm loudspeaker than in a 4 Ohm speaker.

So your answers to my question was not accurate.

This is just one exception out of many to the "mathematic" attempt to analyze this.

So instead of having a simplifiyng point of view to this, I suggest that you approach it with a complex point of view.

So much for these two comment:
"the lower the speaker impedance, the more power you get from the power amp"

"You're new here at ST, and i understand this is a very subjective issue in certain "audio"(?) forums...but here at ST we always try to be very accurate about what sound's concern."

hehehehehehehehe

Get a grip.

And let's move on now in mutual respect instead.

"dolph"

Well, I was not referring to any amp in particular. And this is a SS topic not Tubes.

You’re right in one thing I’m not a big expert in OTL’s, but Imho OTL tube amps or RF amps…. are not a good example when we talk Power vs DB’s.

Why putting questions if you already knows the answer?

As you know OTL’s do not have output transformers, there for no need to transform the high impedence / high voltage / low current signal of the tube to the low impedence / low voltage / high current signal needed to drive loudspeakers. This allows the tubes to be connected directly to the loudspeakers, and………I think you know the rest….or don’t you?!

I know that the guys at Transcendent Sound solved some of the big problems in OTL’s amp designs, but that’s an issue that I never give much attention, but if you have some info about OTL’s that you want to share with us, feel free to do so.

More, I challenge you to do it. Or are you one of those morons like you said you are, that says so much and knows to little???

Keep cool.

Without drowning myself in a sea of techno-speak regarding dbw, SPL and the like, it has been my experience that, within a given manufacturer's lineup, the more powerful amplifier is usually the better performer - not just one capable of playing louder.

Back in the early 70's, Dynaco introduced one of the first (if not, the first) super powerful amplifiers, their A-400, which delivered a then staggering 200 watts per channel into 8 ohms. Most of us were quite content with 45 to 60 watts per channel, and thought that 200 was excessive, and flat out ridiculous. I felt very much that way until I heard the A-400.

Once we connected the amp to the switching panel in my retail store, we all were amazed at how much better the A-400 made so many speakers sound, even including a particular Lafayette/Criterion model most of us thought sounded flat out horrible. Certainly none of the speakers in my Lafayette store was deserving of the term "audiophile-grade," but there was no doubt that something as mundane as the Rectilinear III (a decent, floor-standing speaker that retailed for $279) sounded a whole helluva lot better when powered by the A-400 than anything else available in the store at the time, which included virtually all of Pioneer, Marantz and Kenwood receivers, as well as the lesser powered Dynaco product.

Today, I'm driving my Dahlquist DQ-10's with an Adcom GFA-5800 which pumps out 250 watts per channel into 8 ohms, and 400 into 4 (the DQ-10's are actually a lot closer to 4 than their indicated 8 ohms), and in a larger listening room I used to have, I could occasionally drive the amp into clipping without shattering my eardrums, or breaking any windows. In my current listening room, which is a good deal smaller, it's unlikely I'll ever drive it into clipping, as it gets far too loud long before the setting on the volume control that caused the clipping in my former home. Still, the amp really makes the DQ-10's sing, as I suspect any other decent, high power and high current amp would.

Forget challenges, my friend.
That's just too narcissistic for me.

Just don't talk about always being very accurate about what sound's concern on this forum, as if a new guy like me should be aware of "where I step", when posts of yours are directly wrong in the same breath.

I'm new here but think I have some kind of experience useful for some participants in here.
You should treat who ever you may communicate with in the posts as equal.

If you want to know anything about my background and/or qualifications go and read my intro:

http://www.sound-thinking.org/index.php?sh...t=0&#entry53788

"dolph"