Go Back   Home > Forums > >

Multi-Way Conventional loudspeakers with crossovers

The "Elsinore Project" Thread
The "Elsinore Project" Thread
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 24th November 2020, 06:47 AM   #3361
Joe Rasmussen is offline Joe Rasmussen  Australia
diyAudio Member
 
Joe Rasmussen's Avatar
 
Join Date: Jan 2003
Location: Sydney, Australia
So many people who have built the Elsinores, particular from Mk5 and Mk6 onward (where current EQ was applied, so that the same amplifier has to produce the current and hence the same energy at all frequencies), that they somehow sound different from other speakers. Less Hi-Fi for a start, no artificial brightness, yet intimate with small scale quartets and large scale with orchestral, they just get the scale right. They also sound less constricted, they image like crazy, width and height. If the setup is right with the rest of the systems, I have heard people ask "where are the other speakers in the room?" For that reason, they are also great for movies.

A friend who built them last year replacing $83,000 speakers from Raidho (they are Danish like me) and said just three words "they do everything!"

More recently a number of Elsinore owners have decided to try them with different amplifiers and quite amazed how revealing they can be. You can really hear the difference and yet they are also so amplifier friendly that hardly any amplifier sound bad with them. But still, get the best amp that you can get or afford. I like that.

BTW, I am not saying these things above, they are the ones telling me!

And I did it for free!

As for the theory behind them, that is a different matter and others can disagree, but can they disagree when they haven't even heard them? Let them, but I don't care... besides they only have a partial part of the story.

I am writing a paper, some of it has already been discussed with my peers (and some of them I consider superiors) and it has passed muster. One of the 'shocks' is how the output impedance, particularly LF, an overhung Voice Coil actually swamps the output impedance of the conventional 'voltage source' amplifier and what changing the length of the Voice Coil does to the driver when applying the calculation F=Bli.

Some things are hidden in plain sight. This one is a beauty. You could argue that there is no such thing as voltage drive, except with electrostatic (force=voltage) speakers.

Quote:
Originally Posted by boswald View Post
Whatever the merits on either side, the argument is not about the Elsinores, and should probably have its own thread.
Mods: some help here?
Sadly, when that was tried, the usual suspects turned up, the howler monkeys, so nothing got heard and even less fairly discussed. We are going to have a forum which I hope will be moderated by a person I consider to have considerable stature and it will be via invitation only.

But the forum here is for the DIY constructors and not so much for discussing and disagreeing about theory.
__________________
"Elsinore Project" DIY Speaker System
"Don't speak more clearly than you are able to think." Niels Bohr 1885-1962
  Reply With Quote
Old 24th November 2020, 07:28 AM   #3362
Joe Rasmussen is offline Joe Rasmussen  Australia
diyAudio Member
 
Joe Rasmussen's Avatar
 
Join Date: Jan 2003
Location: Sydney, Australia
Quote:
Originally Posted by mbrennwa View Post
Yes!

The Elsinores are a fine design.

The argument is about the Joes new (?) findings, which he keeps mentioning in this thread. What exactly did he find? Are his conclusions right? Why does he not disclose his news?

Joe, you could start a new thread about your current-drive thoughts in order to keep this thread for the Elsinore builders.
Thanks for your comments, re a new thread, see my reply to boswald at the end of the last post.

First of all, I am not in the current-drive camp. I know this confuses so many and I seem to repeat this so many times, oh well. It is Esa Merilainen who is on a crusade that the world should be converted to current-drive. I am not in that camp!

My interest in this is much broader than that, in fact I am not even on a crusade, I only have an interest in what really happens to the current, whether it is voltage-drive or current-drive, what happens to the current, how does the dynamic loudspeaker respond to the current. The key here is the equation we all know but 99.9% just ignore and it is such a simple equation F=BLi.

"F" = Force actuating the Voice Coil

"B" = This is the strength of magnetic field in the gap where the Voice Coil sits.

"L" = Length of the Voice Coil that sits inside the gap and not the whole Voice Coil. Hence, it is also the same as the gap.

"i" = The current in the Voice Coil.

Only about 30% of the length of the Voice Coil sits inside the gap. So 70% of the circa 6 Ohm DC resistance sits outside the gap. If the VC was a single layer, you would have a near passive 2R on the active side of the amplifier and another 2R on the return side, 4 Ohm in all approx.

Can anybody see a problem with the above and the notion of voltage-drive with a conventional amplifier? For a start, only 30% of the voltage is inside the gap. Something is hidden in plain sight. Based on the above, with the majority of loudspeaker drivers, can it be called voltage-drive? Is there really such a thing as voltage-drive in the first place?

In anticipation, for those who will point to underhung Voice Coil drivers, a closer analysis will disclose the same thing. It does not matter if it is inside or outside the gap. The question will remain whether there is any such notion of voltage-drive in the first place?

My two points are:

1. There is no such thing as voltage drive, all amplifiers are just different forms of delivering current to the driver, the Voice Coil in the gap.

2. We are listening to the current of the amplifier, not its voltage.

That number two will be the most difficult for many to get, but I have asked three physicists who knows their stuff, and they have not disagreed.

BTW, the howler monkeys hate me asking these kind of questions and pointing these things out.

Think of the consequences of such thinking. Crossovers in loudspeakers are current dividers as far as the Bass, Midrange and Tweeters are concerned. Yet we model and design Crossovers according to a voltage model. Here the Elsinores are different, the Crossover is designed to divide current and not voltage. But one is not allowed to say such things? It delights some and infuriate others. I have no answer to that.

-
__________________
"Elsinore Project" DIY Speaker System
"Don't speak more clearly than you are able to think." Niels Bohr 1885-1962

Last edited by Joe Rasmussen; 24th November 2020 at 07:31 AM.
  Reply With Quote
Old 24th November 2020, 08:24 AM   #3363
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by Clausen View Post
Joe did something none of you could do
What is that? As far as I'm aware he's used a Zobel network to flatten the speaker's impedance. Am I missing something else?
  Reply With Quote
Old 24th November 2020, 09:07 AM   #3364
Joe Rasmussen is offline Joe Rasmussen  Australia
diyAudio Member
 
Joe Rasmussen's Avatar
 
Join Date: Jan 2003
Location: Sydney, Australia
Quote:
Originally Posted by scottjoplin View Post
What is that? As far as I'm aware he's used a Zobel network to flatten the speaker's impedance. Am I missing something else?
Yes.
__________________
"Elsinore Project" DIY Speaker System
"Don't speak more clearly than you are able to think." Niels Bohr 1885-1962
  Reply With Quote
Old 24th November 2020, 09:14 AM   #3365
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Will you tell me more? I thought EQ was the crux of the matter
  Reply With Quote
Old 24th November 2020, 01:35 PM   #3366
Stal is offline Stal
diyAudio Member
 
Join Date: Dec 2011
Location: S Wales
He's also flattening the resonant impedance of the drivers with RLCs.
  Reply With Quote
Old 24th November 2020, 01:42 PM   #3367
Stal is offline Stal
diyAudio Member
 
Join Date: Dec 2011
Location: S Wales
Is the notion here that the back EMF of a driver is not a restive but an inductive source. Current lags voltage but a voltage amp sees the back EMF voltage and corrects for it when the current is lagging behind. Do the equalising networks somehow ensure the amp sees the current in phase with voltage so as it corrects for voltage it corrects for current also?
  Reply With Quote
Old 24th November 2020, 01:51 PM   #3368
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by Stal View Post
He's also flattening the resonant impedance of the drivers with RLCs.
Yes, sorry, I was not specific enough.
  Reply With Quote
Old 24th November 2020, 02:36 PM   #3369
scottjoplin is offline scottjoplin  Wales
diyAudio Member
 
scottjoplin's Avatar
 
Join Date: Dec 2015
Location: Penrhyndeudraeth
Quote:
Originally Posted by Joe Rasmussen View Post
I only have an interest in what really happens to the current, whether it is voltage-drive or current-drive, what happens to the current, how does the dynamic loudspeaker respond to the current.
I suggest you measure the current at the output of the amp, and at the driver terminals, and the acoustic output and compare all three.
  Reply With Quote
Old 24th November 2020, 02:51 PM   #3370
Sub Sonic is offline Sub Sonic  Australia
diyAudio Member
 
Join Date: Sep 2013
Location: Adelaide, SA
Quote:
Originally Posted by Joe Rasmussen View Post
My two points are:

1. There is no such thing as voltage drive, all amplifiers are just different forms of delivering current to the driver, the Voice Coil in the gap.

2. We are listening to the current of the amplifier, not its voltage.

-
Makes sense.

Current in a conductor produces the magnetic field, and hence force on the voice coil.

In an imperfect parallel, a carís RPM is related to power, but does not accelerate the vehicle in and of itself, the torque of the engine does.

Current in a circuit is obviously related to voltage, but when a speaker with non flat impedance is mated to amplifiers of different output impedances there will be a varying voltage divider effect - therefore varying current, and therefore varying frequency response. Clearly this will make the same speaker (with non flat impedance) on a low output impedance amp sound different from when a high output impedance amp is used.
  Reply With Quote

Reply


The "Elsinore Project" ThreadHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
"Proac 2.5 clone" or "Elsinore project" Joel Wesseling Multi-Way 10 26th May 2011 06:51 AM
A thread to post your "project files" critofur Multi-Way 10 21st March 2008 01:50 PM
"compact loudspeaker factory visit from "magico mini" thread Nanook Multi-Way 2 4th January 2008 08:30 AM
The "Really simple and cheap speaker designs for the newbie!" thread. Spasticteapot Multi-Way 5 19th March 2006 05:16 AM


New To Site? Need Help?

All times are GMT. The time now is 01:03 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki