Thanks. That's why I asked the question. You used old info.
You can strongly "suspect" whatever you wish. Does one need to read the standard in order to understand the distinction between 50% and 80%?
You stated that amps cannot "double down", which is incorrect. Many do, based on design tradeoffs. Just read what JC wrote.
VC compression is an entirely different issue.
jn
While you use the term "rephrase", I used the quote buttons that are part of this site. You know, the thingies on the right hand side that quotes EXACTLY what the post said..
That's why it's impossible to re-write history as you tried.. Time, date, sequence...it's all there for all to see.
Edit: Hey, let's take that quotey thing for a spin, no?
Hmm. doesn't look like a re-write to me.... Hint: that itty bitty arrow box next to the attribution, click that and you go to the quoted post.
He sent me a link to a viewer which I had previously read (almost didn't, the site was very slow and Asian characters came up first) which provides the 2003 version, and lo and behold, it has 80%. Not 50...80 Hence my question..
Then I can expect that when it does, you'll continue using the 80% old number instead of the then current number?
And to top it off, JC apparently refuses to consider 80% or even 50%..
Given the current state of amplifiers and power and such, I would not expect them to return to 50%. I see many power amps that get so close to the line capacity output wise, that 50% would push the breakers at the load panel too much.
Course, consumer stuff doesn't have that issue.
jn
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My compliments Ed to you and all the great people who as members of the writing group substantially revised and updated AES2-1984 (r2003) to the AES2 –2012. (*)
Oh, no!
Scott are you talking about the magnetic damping as explained in USA patent 3,683,128 text column 3)?
Have you varied the electric cartridge loading on Grado to see the effect on that form of damping? Coil current should play a role.
George
(*)I would say, this brings be back to the early hot years of standards harmonization btn American and European aerospace sector institutions (you don’t want me to put this hat on)
No, the inductance is low enough that there is little/no electrical peaking. It looks more like just the 400 Ohms series R. You know I disagree on this somewhat, at high frequencies the motor assembly and the mechanical elements of the tip mass/vinyl resonance are highly decoupled IMO. At low frequencies that poor little coil wagging the whole arm assembly makes no sense to me either.
EDIT - read the patent, with the fixed flux of the pole assembly I don't see the coil adding much. The flux-bridger (MI) has damping due to moving in the magnetic field of this pole assembly, the coil current would augment this but I don't see much here. I could be all wrong, this is not my field of expertise.
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Hi,
Exactly.
Which is something folks like SY understood ages ago and I refuse to adopt for I know there is no end to what one can pull out of a tube when sound and only sound matters...
There are a thousand recipes in the audio cookbook, closed mindedness is not one of them.
Ciao,
Exactly.
Which is something folks like SY understood ages ago and I refuse to adopt for I know there is no end to what one can pull out of a tube when sound and only sound matters...
There are a thousand recipes in the audio cookbook, closed mindedness is not one of them.
Ciao,
Agreed. However, vacillating on things like impedance minimums is not a good thing. Clear technical reasons for changes are great, but year to year, physics doesn't change that much. Changing back to a previous number indicates both a lack of consensus, and vague arguments on both sides. Honestly, going back and forth like that is something that will cause the industry to ignore the standards, both out of laughter, and cost.
NEC is in the exact same boat. However, they seem more competent in regard to making changes. It could be that they have far more experience.
jn
More respect, please, jn.
3 million people cannot be wrong! Adding jj seals the deal!
Cliff,
You have my sincere apologies. I misread your post.
I will retire to my basement in shame..
To the unimat!!!
jn
The current in a speaker is not building up insteaneous. So it is well known that a good power amplifier can not only provide voltage but a lot of pulse current too. That is especially important nowadays where modern loudspeakers are wideband and linear but do not have high sensitivity because people want small speakers that produce a lot of bass
, sacrificing sensitivity in the process.
How much current do we need ? I tested a lot of even very big woofers, say a JBL 18 " woofer with a 100mm voicecoil. Non of the woofers could stand more then 11A over a sustained period, simply burning the voicecoil. That does not mean that we not need more current over a short period of time to excellerate the driver. I would say that 45A over a 500msec period is fine, even for big Wilsons, Rhaidos and Magicos that set the pace at this moment in time. I do not build current hungry speakers like that but this is not the place to advertise. Problem with say a 300W amp with 45A peak delivery is that the low revel resolution of an amp like that may not be as good as a class A amp with 25W although many of the high power amp makers will not agree. Do not trust me but it is hard to find a huge power amp that sounds " Real".
Concerning an FFT on an only positive going signal ( e.g "noise" ), where is the problem ?
Are you all stupid discussing this in public ? I thought you are the experts.
Even Fourier allowed Sine, Cosine and Half Cosine ( only positive going ).
Here is a text ( sorry in german, i break the rule ) :http://www.kirchner-elektronik.de/~kirchner/photostoryteil2.pdf
, sacrificing sensitivity in the process.
How much current do we need ? I tested a lot of even very big woofers, say a JBL 18 " woofer with a 100mm voicecoil. Non of the woofers could stand more then 11A over a sustained period, simply burning the voicecoil. That does not mean that we not need more current over a short period of time to excellerate the driver. I would say that 45A over a 500msec period is fine, even for big Wilsons, Rhaidos and Magicos that set the pace at this moment in time. I do not build current hungry speakers like that but this is not the place to advertise. Problem with say a 300W amp with 45A peak delivery is that the low revel resolution of an amp like that may not be as good as a class A amp with 25W although many of the high power amp makers will not agree. Do not trust me but it is hard to find a huge power amp that sounds " Real".
Concerning an FFT on an only positive going signal ( e.g "noise" ), where is the problem ?
Are you all stupid discussing this in public ? I thought you are the experts.
Even Fourier allowed Sine, Cosine and Half Cosine ( only positive going ).
Here is a text ( sorry in german, i break the rule ) :http://www.kirchner-elektronik.de/~kirchner/photostoryteil2.pdf
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Joachim, most people here do not have your experience in speaker design, and I doubt that they read as much as you, either. Heck, I bet that I have more knowledge and experience than 90% of my critics here, when it comes to speaker design. Thanks for the technical input, even though it is in German. It is refreshing to see that real speaker research is being done SOMEWHERE! Not so much in the USA, anymore.
Just give me the minimum Z number, please -
I am not sure what the reason is to find a single number for a speaker's variable Z. Unless, it is to appease commercial interests, primarily. I mean it is not like the 50 Ohm or 75 ohm Z standards.
After all, don't amps need to handle cleanly the speakers minimum Z at all times? I dont want to know the 50 or 80% value. Just give me the lowest Z value, thank you.
THx-RNMarsh
I am not sure what the reason is to find a single number for a speaker's variable Z. Unless, it is to appease commercial interests, primarily. I mean it is not like the 50 Ohm or 75 ohm Z standards.
After all, don't amps need to handle cleanly the speakers minimum Z at all times? I dont want to know the 50 or 80% value. Just give me the lowest Z value, thank you.
THx-RNMarsh
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I just confirmed there is about a 10:1 difference in inductance between the Grado and the AT cartridge I have here. That would move the resonance up a bunch for the Grado. He would need to control the tip resonance to get flat response very differently than the AT/Shure design.
> Here is a text ( sorry in german, i break the rule ) :http://www.kirchner-elektronik.de/~k...storyteil2.pdf
But there is an English version :
http://www.kirchner-elektronik.de/~kirchner/LoadspeakerMeasurementTechnology.pdf
Patrick
But there is an English version :
http://www.kirchner-elektronik.de/~kirchner/LoadspeakerMeasurementTechnology.pdf
Patrick
My take on the issue is this-
In the early vacuum tube days there was an optimum impedance to get the most power from an amp. Going much higher or lower would lose power since the amp was both voltage and current limited around that optimum load. Selecting taps on the output transformer gave flexibility in optimizing the maximum power for the speaker.
Speakers are current driven but are nominally flat response with respect to the voltage drive (like a motor) and perhaps are best thought of as motors run on a constant voltage needing different current as the circumstances require.
Solid state amps are not optimized for the load in the same way since they are more of a pure voltage drive until either the fuse blows or the smoke gets out. Perhaps describing a speaker as having a voltage sensitivity and a peak current requirement at a max voltage would better define the requirements for an amp to drive the speaker. Much as the current rating for a branch circuit to drive a big motor running an air compressor. I would not want to try to write the ad copy for an amp or speaker rated this way. Its much different from existing practice.
> Here is a text ( sorry in german, i break the rule ) :http://www.kirchner-elektronik.de/~k...storyteil2.pdf
But there is an English version :
http://www.kirchner-elektronik.de/~kirchner/LoadspeakerMeasurementTechnology.pdf
Patrick
The paper is interesting but the translation is clumsy making some of the info unclear. I also get a bit of self promotion in it focused on a different way to measure speakers that suggests the way we have been is not correct? If anyone has experience with the system please share. Its not too expensive and may be a worthwhile investment.
I agree completely.
While all that is true, real life is moving in different directions. For a start, we see mass manufacturers using relatively weak power devices, and prescious few of them. We see amps rated at many huindreds of watts derived from two pairs of 130 or at best, 150W power devices. If that's not pushing it, then I don't know what pushing is.
The Japanese audio industry in particular is absolutely obsessed with SEPP output stages, reasoning that it's easier to pair one pair of devices than 2, 3, 4 or more of them. For example, the Marantz "de luxe" series model PM-11S claims 20-20,000 HZ ontinuous power output of 100/200W into 8/4 Ohms with one pair of 2SC2922/2SA1216. WEhile these are robust devices, I still can't stomach the 4 Ohm rating, however I look at it, in my book those devices will melt down for anything but a quick transient.
And I wondered, before seeing the service manual, why it sounded thin
to me. Balls made of glass, not brass.
But then, it all boils down to what you design the amp for. If it's just for show, the above works, but if you want true grit, you will need at least 3 pairs of preferably 200W output devices (e.g. MJL 3281/1302 from Motorola/ON Semi).
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