And for me, your answer the typical illustration of preconception.
I don't want to offend-you, but it's a position that seems common when I read you.
Argues and suppositions has no value in front of experiments and measurements.
Had-you tried ? Obviously not. Had-you made comparative distortion measurements on real loads ? Obviously not.
This has been experimented by many people and a lot of blind tests done on this matters by a friend owning a shop of speakers and kits. During years with a lot of customers. You can see the changes on the response curve as well. Well, i will not spend hours on this subject, everybody can decide his way for himself. On my side, I don't like to add complexity and extra money for nothing.
... I should just add that, once a speaker has been compensated to be flat on impedance, passive filters are easier to design, as calculations will give the expected result.
I do not like to fumble like a monkey with a pile of capacitors and chokes with my plotter, breaking my ears with slippery frequencies.
For those who are interested, full of information and calculation tools on this site: Les menus du chapitre : Filtres
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I guess you are so busy doing tests with your friend with a shop to visit volumes | Linear Audio
I know this and ?
Have-I to be impressed ? Do-you mean jan is some kind of Moise that owns the tables of the hifi laws directly from the hands of God ?
I am old enough with a full *professional life* in this domain to can trust my own experiences more than the words of any forum's "gurus". ;-).
And I do not impose any of my points of view, neither.
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Well in your previous post you say that you flatten the speaker impedance for, among other reasons, so the amp has no longer to deal with non-linear voltage and current. I fail to see the connection between the two, but maybe you can educate me? Always willing to learn.
Ohh, and your statement "And I do not impose any of my points of view, neither." must be the understatement of the century. Even if it is only 18 years old ;-)
Jan
Ohh, and your statement "And I do not impose any of my points of view, neither." must be the understatement of the century. Even if it is only 18 years old ;-)
Jan
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Easy: Experiment.
I know you are experienced enough to know how to drive those experiments, listening and measurements.
And i will read your results with interest, trying to understand why they contradicts mine, if they do, with an open mind.
Oh, about your "understatement", i have two answers.
On my side, I do not pretend to defend what is "politically correct" in matter of audio, and i am here under a pseudo, to protect my words from any "authority arguments".
Nobody is obliged to believe-me, I'm only a cartoon character, and, anyway, to believe is not the good way. ;-)
Sincerely yours,
Tryphon Tournesol
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I also use networks to flatten the impedance of loudspeakers. Makes a significant and measurable difference on my size projects.
So the actual issue is at what size (Shorter distances) does it no longer matter?
In reality at my scale measurement resolution is often only to about +/- 1 dB. It is common to see folks try to tune better than that with usually horrible results.
(Wind!)
So the actual issue is at what size (Shorter distances) does it no longer matter?
In reality at my scale measurement resolution is often only to about +/- 1 dB. It is common to see folks try to tune better than that with usually horrible results.
(Wind!)
No, the point is that Jan hangs around with some serious clever and clued up people. He has published their work on top of his own research over (mumble) decades. He is able to enter into a debate on things.
You appear to present things as the one and only fact and then get offended when others disagree. Backing up some of your contentious theories with measurements might help as you say you have taken them.
And Jan isn't hiding behind a pen name. You can look him up.
You know, this is very tiring. You (and others) make a factual claim or statement, someone (me and others) ask for some back-up, facts and figures, proof. All that comes out is equivalent to 'I heard it clearly, I trust my ears'.
Saying that flattening an impedance response lowers non-linear voltage and current is a technical claim, and people should be able to ask - and get - a technical explanation. Measurements, before-after, that kind of thing. You make the claim, you provide the proof. Because if you are right that is an important piece of info for which we would thank you.
Jan
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You are playing the player, again here, do-you have to say something on the subject ?
As I said I will read anything about serious *studies* measurements and blind tests that contradict my personal experiences with interest and attention.
But i'm not interested in words referring only to a supposed knowledge of a correct use of a so calling science. Or voting intentions on who's right or wrong. This was a subject i worked on, years ago.
This is technology and psycho acoustic. Too complex and numerous phenomenas to be resumed with simple formulas and general knowledge which reassure the objectivists.
This don't imply we don't have to apply what we know about the laws of physics the best we can because they are stubborn.
I said making speakers assemblies with a flat impedance curve and equivalent filters gave more pleasant listening results *on my experience*.
And that it has been confirmed by a lot of people. I participated in several listening tests as well.
It is not a law, it is a tip.
Nothing that contradict any laws of physics. Measurements of pulse response and distortions show visible differences with various amplifiers. That justify why we can ear differences.
Now, if you try to linearize your speakers and, at the end, prefer them with or without, what the hell ?
May-be I am wrong when I try to understand the physical phenomenas at work, but, what the hell ?
It worked for me, it works for others too: the first thing i do, when i receive a new speaker is to design its compensation network.
Enough for me on the subject, useless controversy is boring and you can continue to design speakers that goes under 2 Ohms and up to 50 if you want.
Jan, can't-you understand that, if may-be -and I'm not even sure- i have some B&K papers left somewhere in an old trunk, it would take me hours to find them ?
All the measurements made at this time 3 or 4 decades ago where for designing a commercial product, not to write an article.
They were done with measurement instruments, like distortion meters, voltmeters etc... that did not "printed" anything.
Computers and printers were not there yet, and who cares to take pictures of measurement meters during a work in progress in a R&D office or an anechoic chamber ?
I'm sure you can understand this.
The only thing that i can say is what I did, in a friendly purpose: It is worth a try.
And sorry if i over reacted to your "anthropomorphism" ironical remark. I am not this king of snake oil customer to believe gold brings a golden sound
and I found that a bit ... condescending.
Go ahead John. Not forgetting how power supplies can react during transients.
Here is the curve as measured by 'Stereophile' on the WATT1 speaker impedance. Pretty scary! It is probably caused by a single L-C combination to ground in order to correct for tweeter fundamental resonance. Of course, it was an oversight, but hard to fix without changing the entire Xover, from what I gather.
For the record, Matti Otala's work on speaker impedance is paramount to get a more 'worst case' understanding of speaker loads.
For the record, Matti Otala's work on speaker impedance is paramount to get a more 'worst case' understanding of speaker loads.
Attachments
Maybe they should "Ask Cortana". There are certainly two sides to this question, does designing a speaker with a dip to 2 Ohms or less over a portion of the frequency range do something special for the speaker or does making every PA capable of driving this load compromise an otherwise good amplifier.
I have no problem favoring a speaker that might limit amplifier choices but the industry standard "we recommend a minimum of 100W amplifier" is essentially useless information.
Need a simple LRC network to flaten the resonance impedance. Then, easy to sculpt the response curve by a serie/parallel network keeping the impedance flat, amp side, if any need.
But, then, why to chose a tweeter with an accident there when so many on the market ?
Anyway, not a correct design on my opinion.
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I think QES/QTS is important too. Different amps will sound better and worse with different QTS combinations.
When you put that .5ohm resistor in series with the Wilson, you moved the QTS up considerably.
Hi Zaphod,
When I rebuild a good amplifier, I don't leave it stock. I make all kinds of upgrades, some are just as simple as tightly matching any diff pairs. With the 500, I also replace some of the transistors with new parts (same number, or a better part). For the 500, I used a set of modern output transistors. That amplifier sounded considerably better than the original, and those comments were made by others. The same is true for the 300DC. I also have an SC-9 (basically a 3650) that suffers from the same switch issue. I'll be designing a new preamp for that position soon. Too bad you are so far away. I would have loved to have your 500. I always work on other people's equipment, and seldom my own. Everything I own has been on the bench to extract the best performance from it. No, I don't do the electrolytic cap replacement and call that a rebuild.
I think the most difficult Marantz receivers to work on where any of the four channel models, and almost any Marantz receiver over 25 watts per channel's MPX circuit board.
Hi John,
If an amplifier is less stressed, it's performance will improve as well. We see that all the time as differences between no-load, 8 R load and a 16 R load. It's an easy test to set up, and the results even make sense.
-Chris
When I rebuild a good amplifier, I don't leave it stock. I make all kinds of upgrades, some are just as simple as tightly matching any diff pairs. With the 500, I also replace some of the transistors with new parts (same number, or a better part). For the 500, I used a set of modern output transistors. That amplifier sounded considerably better than the original, and those comments were made by others. The same is true for the 300DC. I also have an SC-9 (basically a 3650) that suffers from the same switch issue. I'll be designing a new preamp for that position soon. Too bad you are so far away. I would have loved to have your 500. I always work on other people's equipment, and seldom my own. Everything I own has been on the bench to extract the best performance from it. No, I don't do the electrolytic cap replacement and call that a rebuild.
I think the most difficult Marantz receivers to work on where any of the four channel models, and almost any Marantz receiver over 25 watts per channel's MPX circuit board.
Hi John,
If an amplifier is less stressed, it's performance will improve as well. We see that all the time as differences between no-load, 8 R load and a 16 R load. It's an easy test to set up, and the results even make sense.
-Chris
Its not so clear to me that use of the word deal implies anthropomorphism. "Deal" is not a human emotion or other aspect of personality, nor a reference to another human characteristic. Perhaps other terminology such as "expend or otherwise utilize limited gain structure resources for" could have been substituted. Certainly I didn't get the sense that the use use of the word was used intentionally or unintentionally to attribute human characteristics to an amplifier.
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