Joe,
Please follow the process I have explained:
1. For Quote Function please click on the "+ icon - it will change color from blue to orange and show "- .
2. Then click on Reply - you should have the previous post within "quote" for your reply.
Image attached.
Attachments
Back to Elsinore build discussions hopefully!
my mahogany wood slab have been air dried since Mar2020, with dry season here and the wood placed in a hot room with pocycarbonate roof. around 32°C all day with less rainy day.
i tried to cut the translam template with jigsaw and really bad idea. it takes a long time and hurt my hand. i'm saving money to buy a proper bandsaw.
but more importantly, another saving for the tweeter & waveguide
Attachments
Why are you guys giving Joe such a hard time? He’s created something special for the DIY community. He has a lot of issues in his life now. Do you want to drive him away? He’s a thinker with lots of ideas. If you disagree, can’t you be a little more respectful, and maybe take the arguments to a thread for theoretical discussions?
Thank you Joe. The whole point being, as I believe you know, is that it doesn't follow that the observed current distortion translates into an acoustic distortion. It would be interesting how much, if any does, more than interesting, in my view, central to your whole idea.
Hi,
I've been reading last posts from here and this leaves me... kind of disappointed I should say.
When in doubt, just hook-up to undisputable physics laws.
So let me remind here that a conductive "path" being moved while into a magnetic field is subject to an EMF (yes: ElectroMotive Force= Voltage)
So now...food for thoughts:
What could then happen between the ends of a voice-coil while mechanically moved (by the membrane spring...) each time the electric signal driving it is weaker than the mechanical energy stored into the membrane spring (i.e.when changing direction)??
Hint: the coil is placed inside the magnet field.
==>Yes, a Voltage develops across it during these time slots.
This is no religion of any kind, as anyone could check: it is what happens inside any motor
Does anyone remember this below?
Voltage=-d(magflux)/dt
This equation rules any inductor into a transformer or a motor or...a loudspeaker:
When giving back its stored energy, all inductors exhibit voltage, was this inductor a simple piece of wire, as short as anyone would want it to be.
This voltage is always in opposite direction than the voltage which created the energy storage in the first place.
This is how an inductor, fed with a sinewave voltage, lets a phase-shifted current to flow into it: I won't explain this basic phenomenon here, but please understand that this phase-shift creates the difference between Resistance and Impedance.
So yes, in a magnetic element (i.e. loudspeaker) what makes impedance is the effect of inductor's back EMF.
That's physics and nothing else.
Be sure that there are technical domains -not HiFi - where this is a complete no-brainer and is so obvious that it could never be a discussion topic.
Joe may not have the exact wording to express it out clear, but down to the detail, there actually is Back ElectroMotive Force into a loudspeaker at regular points in time (i.e. when playing tones).
To me, this explains the somewhat confusion that gets good wills to disagree.
Hope this helps.
I've been reading last posts from here and this leaves me... kind of disappointed I should say.
When in doubt, just hook-up to undisputable physics laws.
So let me remind here that a conductive "path" being moved while into a magnetic field is subject to an EMF (yes: ElectroMotive Force= Voltage)
So now...food for thoughts:
What could then happen between the ends of a voice-coil while mechanically moved (by the membrane spring...) each time the electric signal driving it is weaker than the mechanical energy stored into the membrane spring (i.e.when changing direction)??
Hint: the coil is placed inside the magnet field.
==>Yes, a Voltage develops across it during these time slots.
This is no religion of any kind, as anyone could check: it is what happens inside any motor
Does anyone remember this below?
Voltage=-d(magflux)/dt
This equation rules any inductor into a transformer or a motor or...a loudspeaker:
When giving back its stored energy, all inductors exhibit voltage, was this inductor a simple piece of wire, as short as anyone would want it to be.
This voltage is always in opposite direction than the voltage which created the energy storage in the first place.
This is how an inductor, fed with a sinewave voltage, lets a phase-shifted current to flow into it: I won't explain this basic phenomenon here, but please understand that this phase-shift creates the difference between Resistance and Impedance.
So yes, in a magnetic element (i.e. loudspeaker) what makes impedance is the effect of inductor's back EMF.
That's physics and nothing else.
Be sure that there are technical domains -not HiFi - where this is a complete no-brainer and is so obvious that it could never be a discussion topic.
Joe may not have the exact wording to express it out clear, but down to the detail, there actually is Back ElectroMotive Force into a loudspeaker at regular points in time (i.e. when playing tones).
To me, this explains the somewhat confusion that gets good wills to disagree.
Hope this helps.
-1
The only one giving Joe a hard time is Joe himself.
Scott Wurcer: "you have an amazing resistance to getting a grasp of the very basic definitions (for years)";
mbrennwa: "I believe things would be much easier to understand if you'd be a bit more careful about the terminology, wording and language context of your arguments".
As long as Joe continues to use vague terminology he is asking for and will be faced with opposition.
This thread is for Elsinore builders.
Joe might open another thread to discuss his last findings about the current drive thing, but he announced that this forum is not the right place.
A pity. In my view that does not help his credibility.
We don't.
The only one giving Joe a hard time is Joe himself.
Scott Wurcer: "you have an amazing resistance to getting a grasp of the very basic definitions (for years)";
mbrennwa: "I believe things would be much easier to understand if you'd be a bit more careful about the terminology, wording and language context of your arguments".
As long as Joe continues to use vague terminology he is asking for and will be faced with opposition.
Agree.
This thread is for Elsinore builders.
Joe might open another thread to discuss his last findings about the current drive thing, but he announced that this forum is not the right place.
A pity. In my view that does not help his credibility.
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Hi Joe,
I recall a demonstration you did for the Melbourne audio club. The tenure of this thread is a testimony to your ability apply working knowledge of loudspeaker design theory into a practical design.
My take on the recent discussions is that a lot of technical disagreements emerge once the discussion takes on a practical scenario where
a sunny day scenario seldom exist in the real world. Long held beliefs based on theoretical ideals become sensitive to changes in interpretation because the assumptions a theory is base on are not always valid. My advice is ignore those who’s rigid mindset makes it difficult for them to accept things unless they are in precise terms they understand. In that respect what you are seeing is their vulnerability. It’s not your problem.
It’s a bit like me saying well l just had a meeting with the interstellar space commerce commission to approve mining transluminum on Mars. To the uninitiated they would be quite confrontational because to them it’s something they don’t understand yet. (Transluminum is a Transparent Aluminium alloy. A futuristic material for construction of fish tanks in 2560 AD).
A working knowledge of electrical theory is quite useful. A woofer if modelled properly is a complex electromechanical device.
For example a crossover choke in series with a woofer in an enclosure actually has the effect of modulating the voltage drive below 150 hertz due to the change in the motional impedance of the driver. This is based on measurements with LinearX Lms. The net effect of this is variations in the voltage drive resulting in amplitude changes in the driver output. In some instances this is referred to as passive gain caused by the passive network.
A complex conjugate network on the woofer of some 20 elements will linearise the effect but at significant cost.
If an arrangement could be devised to sense the variations in the voltage drive at the loudspeaker driver terminals and feedback as a correction to the amplifier the results would be very interesting. I can post a measurement if you wish.
I recall a demonstration you did for the Melbourne audio club. The tenure of this thread is a testimony to your ability apply working knowledge of loudspeaker design theory into a practical design.
My take on the recent discussions is that a lot of technical disagreements emerge once the discussion takes on a practical scenario where
a sunny day scenario seldom exist in the real world. Long held beliefs based on theoretical ideals become sensitive to changes in interpretation because the assumptions a theory is base on are not always valid. My advice is ignore those who’s rigid mindset makes it difficult for them to accept things unless they are in precise terms they understand. In that respect what you are seeing is their vulnerability. It’s not your problem.
It’s a bit like me saying well l just had a meeting with the interstellar space commerce commission to approve mining transluminum on Mars. To the uninitiated they would be quite confrontational because to them it’s something they don’t understand yet. (Transluminum is a Transparent Aluminium alloy. A futuristic material for construction of fish tanks in 2560 AD).
A working knowledge of electrical theory is quite useful. A woofer if modelled properly is a complex electromechanical device.
For example a crossover choke in series with a woofer in an enclosure actually has the effect of modulating the voltage drive below 150 hertz due to the change in the motional impedance of the driver. This is based on measurements with LinearX Lms. The net effect of this is variations in the voltage drive resulting in amplitude changes in the driver output. In some instances this is referred to as passive gain caused by the passive network.
A complex conjugate network on the woofer of some 20 elements will linearise the effect but at significant cost.
If an arrangement could be devised to sense the variations in the voltage drive at the loudspeaker driver terminals and feedback as a correction to the amplifier the results would be very interesting. I can post a measurement if you wish.
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It is often wise to read the Site Announcements.Credibility Police
This is a thread about Joe’s design, which many of the readers here are building. Why exactly should Joe face “opposition” on a thread dedicated to helping people realize his creation, that he has freely shared with others? Don’t you have something better to do? Aren’t there other places where you can wield your finely honed “opposition“ skills?
It’s one thing to ask questions or request clarifications, but to attack like this, using “opposition” seems very inappropriate in this environment.
“Faced with opposition”? For using “vague terminology”? What?
This is a thread about Joe’s design, which many of the readers here are building. Why exactly should Joe face “opposition” on a thread dedicated to helping people realize his creation, that he has freely shared with others? Don’t you have something better to do? Aren’t there other places where you can wield your finely honed “opposition“ skills?
It’s one thing to ask questions or request clarifications, but to attack like this, using “opposition” seems very inappropriate in this environment.
When I encounter the work of someone who lacks credibility, I leave; life’s too short. But evidently you’ve made different life choices. Are you a volunteer cadet in the Credibility Police?
Joe himself steps into a discussion on the subject of current drive on this very thread, and other thread(s) in the past.
When you would look a bit further on this forum you will find a former discussion (Blowtorch thread), and maybe understand what I mean: the opposition is not from today.....
And by the way: the opposition does not come from me...
When you would look a bit further on this forum you will find a former discussion (Blowtorch thread), and maybe understand what I mean: the opposition is not from today.....
And by the way: the opposition does not come from me...
What we have is a classic example of an "echo chamber."
My 'language' is described in a very negative terms as being 'vague' among a certain group of people on www.diyaudio.com and they repeat each other and the 'point' get so magnified that it cannot be drowned out. Somewhat also like a self-fulfilling prophecy. It is one on the evils of social media. It is also one I neither condone or would ever join into. A nasty practice.
My language has always been precise and never vague.
I choose my words with extreme care!
In 45 years I have dealt with government officials, engineers of every stripe, numerous scientists and more. I have been a respected consultant and my input always valued. Many of the above have become lifelong friends.
I have never been accused of being vague or imprecise.
ONLY HERE ON THESE FORUMS!
It is complete nonsense and they should desist, because in tearing down my reputation, they are in fact damaging their own!
Which they strangely can't see. It is character assassination and has become quite a blood sport. Too bad for the victims and egos rule supreme in such an atmosphere.
Confucius say: "He who throws mud loses ground."
C'est la vie.
My 'language' is described in a very negative terms as being 'vague' among a certain group of people on www.diyaudio.com and they repeat each other and the 'point' get so magnified that it cannot be drowned out. Somewhat also like a self-fulfilling prophecy. It is one on the evils of social media. It is also one I neither condone or would ever join into. A nasty practice.
My language has always been precise and never vague.
I choose my words with extreme care!
In 45 years I have dealt with government officials, engineers of every stripe, numerous scientists and more. I have been a respected consultant and my input always valued. Many of the above have become lifelong friends.
I have never been accused of being vague or imprecise.
ONLY HERE ON THESE FORUMS!
It is complete nonsense and they should desist, because in tearing down my reputation, they are in fact damaging their own!
Which they strangely can't see. It is character assassination and has become quite a blood sport. Too bad for the victims and egos rule supreme in such an atmosphere.
Confucius say: "He who throws mud loses ground."
C'est la vie.
