New book: Current-Driving of Loudspeakers

[nightflier]

I saw this on Enjoy the Music.com, and thought it was interesting. I wonder what it will do for speaker manufacturing:

A new book titled Current-Driving of Loudspeakers by Esa Meriläinen ($27.76) demonstrates new process for loudspeaker feeding. Meriläinen argues that conventional loudspeaker technology is flawed and introduces a new method for loudspeaker feeding called current-drive. According to Meriläinen, all audio power amplifiers in use today deliver voltage signals despite the fact that electrodynamic speakers respond only to current. Meriläinen argues that virtually all speaker systems have been severely impaired by the diverse electromotive forces induced in the voice coil that corrupt the flow of current. In response, he has developed new design practices and example circuits to operate the loudspeaker by controlled current, eliminating major distortion factors and offering what he feels is a superior listening experience. "Why have the basic laws of electrodynamics been ignored in the design of all loudspeaker operations?" Esa Meriläinen asks. "These design flaws affect the quality of all sound produced by loudspeakers everywhere and therefore perhaps even the musical preferences and choices of our entire culture." In addition to new concepts for amplifier and speaker design and demonstrative projects, the book also features ideas for modeling, filter design, measurements, and protection and provides a useful tutorial on analog linear systems. It can be purchased from Amazon.com at this link.

[poppachubby]

Looks great Flier, thanks for the rec.

[Luvin Da Blues]

I haven't read the book but this doesn't make any sense at all. Current in a electrical circuit is a function of applied voltage and loading in the circuit, unless he is introducing a varying secondary load (not a good thig) I can't see how this would work.

[pixelthis]

I haven't read the book but this doesn't make any sense at all. Current in a electrical circuit is a function of applied voltage and loading in the circuit, unless he is introducing a varying secondary load (not a good thig) I can't see how this would work.

I agree, voltage is only the pressure that drives current .
You can trade one for the other, as in the high power section of a CRT set,
but you have to have both.
Havent looked at this one, but on first glance its looney tunes.

[nightflier]

Well yes, I know it sounds a bit out there, but I hardly think there would be a book about it if it was nonsense.

[pixelthis]

Well yes, I know it sounds a bit out there, but I hardly think there would be a book about it if it was nonsense.

I don't know about that, theres' tons of books out there about socialism.
John KENNETH GRAILBRAITH , and the brainless idiot , John Maynard keynes,
that he worships at the feet of, both won noble peace prizes and neither knows beans
about economics.
Current is like water, , voltage is water pressure.
What you stated was that voltage is favored by current speaker designers.
Thats like saying that a water company favors water pressure over water.
But I am not surprized, with the current state of intellectual discourse the way it is,
the college student who vetted this book probably has the equivalent of a eight grade
education, if that much.

[atomicAdam]

I don't know about that, theres' tons of books out there about socialism.
John KENNETH GRAILBRAITH , and the brainless idiot , John Maynard keynes,
that he worships at the feet of, both won noble peace prizes and neither knows beans
about economics.

Why do you do this? Why can't you just stick to audio stuff in this part of the forums? There has to be an audio or video example you can use in this case instead of getting political, which, is pretty much just flame bating.

[pixelthis]

Why do you do this? Why can't you just stick to audio stuff in this part of the forums? There has to be an audio or video example you can use in this case instead of getting political, which, is pretty much just flame bating.

SIMPLE... if I talk about "power cords", "that great (ahem) tube sound", or any of the other five thousand audiophile fantasies floating around right now, its off to the races.
This sounds like yet another fantasy concocted to sell the audio eqivalent of pet rocks,
like we need another one.

Anyway it was poorly stated, you can construct speakers that use more current
than voltage(or relatively more) but I FAIL TO SEE THE POINT.But then again I fail to see the point in a "power cord" that sells for hundreds, and comes outta the same plant as one that sells at WALFART FOR A BUCK FIFTY.
Anyway, whatever this guys selling, I BET someone will buy into it.
Like P.T Barnum said, theres' a sucker born every minute.

[pixelthis]

And you can only buy so many overengineered "power cords".

[harley .guy07]

I believe you guys tobe right on this one. You need both I would not see it being able to be done in the way that he explained unless he just does not explain things well and he missed a lot of info but from what he said he does not have a valid idea in my book

[nightflier]

Well here is the author's website:

http://www.current-drive.info/

Again, I'm no engineer, I leave that to those who know. But if Esa Meriläinen is correct in his conclusions than this is definitely a big deal for speaker manufacturing. Pix, I'm not going into a politics discussion about this, that's too far off topic, however, books in the hard sciences typically don't get published unless there's some viability behind them. I'm curious if this is the case here, from some of you who know more about electrical engineering than I do.

[E-Stat]

According to Meriläinen, all audio power amplifiers in use today deliver voltage signals despite the fact that electrodynamic speakers respond only to current.

Apparently, he is unaware of the Nelson Pass designed First Watt F4 which is a current amplifer having no voltage gain.

Meriläinen argues that virtually all speaker systems have been severely impaired by the diverse electromotive forces induced in the voice coil that corrupt the flow of current.

Except when you have no voice coils at all in the case of electrostatics. They are inherently high impedance voltage driven transducers.

rw

[nightflier]

eStat, can you elaborate? I don't think Meriläinen can account for every amplifier made, and I don't know the Pass designed one as well, either, but generally speaking he's right, no? I also think he's talking primarily about cone/box based speakers, which still represents the vast majority of speakers out there. If he's right, those are the manufacturers I was referring to in my comment about this being a big shift in the industry.

[E-Stat]

eStat, can you elaborate?

Sorry, I had intended to link to more info about the product. Essentially, it multiplies the current from the preamp.

F4

I don't think Meriläinen can account for every amplifier made, and I don't know the Pass designed one as well, either, but generally speaking he's right, no?

Generally yes, but I'm put off my his "virtually all amplifier" comment.

rw

[audio amateur]

I bet the pedals in the S2000 are ideal for heal and toe. Must be a blast!
http://www.youtube.com/watch?v=VWWPg8_Xlw0
(unfortunately no camera on the pedals in this one)

[E-Stat]

But I can understand that when 95% of automobiles in the US are automatic.

That's part of my craziness. 100% of mine are not.

I bet the pedals in the S2000 are ideal for heal and toe. Must be a blast!
http://www.youtube.com/watch?v=VWWPg8_Xlw0
(unfortunately no camera on the pedals in this one)

The S has a tight cabin that works well for compact guys like me. Both it and the TL have good dead pedals, too.

That was a fun video. Notice the pilot kept the engine on boil most of the time just touching the 9k redline every once in a while (my petite wife has discovered the fuel-cutoff limiter at 9200!)

The 6-speed A Spec TL does pretty well, too with 0.9 G cornering and similar acceleration and top speed - that is easier to achieve with the larger motor's torque. Its shifter, like all Hondas moves like a rifle bolt, although the throw with the S is so short so you can nearly shift using wrist movement alone.

rw

[audio amateur]

Both it and the TL have good dead pedals, too.

What do you mean by dead pedal?

That was a fun video.

You betcha. I could spend days watching Best Motoring videos, those guys are awesome.
Problem is I just go mad because during term time when im not living at home i dont have a car which means I dont get to drive... and as you can probably tell I love driving (maybe I should say obsessed.) The Honda 2K engines are super high revving as you know which means you need to keep the needle up there (in this case digital) to maintain the power up.
Here is one of my favourites from Best Motoring, but notice it's not a race.
http://www.youtube.com/watch?v=aal9kG-EXeY
I just love how the Skyline's revs just fly! It is incredibly fast, more so than a Ferrari F-40. That's telling you something!
And here's a race with plenty of exotics, including my personaly favourite, the Murcielago. You can fast forward a little as it's quite long.
http://www.youtube.com/watch?v=VE5M_CHfWR8

The 6-speed A Spec TL

Pardon the lack of knowledge, is that an Acura? (Acura doesn't exist in Europe)

Its shifter, like all Hondas moves like a rifle bolt, although the throw with the S is so short so you can nearly shift using wrist movement alone.

I can imagine

[E-Stat]

What do you mean by dead pedal?

That's the old timer's term for a foot rest. It gives you a firm footing for hard cornering and provides a place so that you don't ride the clutch. The worst thing you can do with a clutch is ride it with a bit of pressure. I've known folks who've gone through them in 30k miles - where I'm accustomed to getting more than 100k miles.

Problem is I just go mad because during term time when im not living at home i dont have a car which means I dont get to drive... and as you can probably tell I love driving (maybe I should say obsessed.)

Moi aussi. I could never be an urban dweller for that reason.

Here is one of my favourites from Best Motoring, but notice it's not a race.

Thx for the links.

Pardon the lack of knowledge, is that an Acura? (Acura doesn't exist in Europe)

That's right. The TL is a fancier, higher performance Accord.

rw

[audio amateur]

That's the old timer's term for a foot rest. It gives you a firm footing for hard cornering and provides a place so that you don't ride the clutch. The worst thing you can do with a clutch is ride it with a bit of pressure. I've known folks who've gone through them in 30k miles - where I'm accustomed to getting more than 100k miles.

Oh right, I wasn't aware of that term (or any term which made reference to that 'pedal'). I always take my foot off the clutch pedal when I'm not shifting. It's also handy when you need to push yourself snug in the seat.

Moi aussi. I could never be an urban dweller for that reason.

Well then you can imagine my frustration. In the meantime, I'm being 'greener'. As a result I get to compensate for that when I do drive Unfortunately what I get to drive is a mark 3 diesel Golf. Not exactly the ultimate driving machine...

Thx for the links.

In my case, it got addictive!

That's right. The TL is a fancier, higher performance Accord.

ok!

[nightflier]

Glad to see there are a few other people here who still drive a stick. Same here, never had an automatic and while it makes car shopping a pain, I persist in looking for that elusive stick, even in the larger & luxury segment. Since my Saab 9-5 now has some new life in it, I'm actually thinking about chipping it and buying some upgrades.

Getting back to the OT, maybe before we tear each other new ones over the merits of current-driving loudspeaker technology, someone should buy the book and read it. I can't really say I'm a good candidate for that since most of the engineering involved will be lost on me. Anyone else have an inkling to buy it?

[rakeford]

Glad to see there are a few other people here who still drive a stick. Same here, never had an automatic and while it makes car shopping a pain, I persist in looking for that elusive stick, even in the larger & luxury segment. Since my Saab 9-5 now has some new life in it, I'm actually thinking about chipping it and buying some upgrades.

Getting back to the OT, maybe before we tear each other new ones over the merits of current-driving loudspeaker technology, someone should buy the book and read it. I can't really say I'm a good candidate for that since most of the engineering involved will be lost on me. Anyone else have an inkling to buy it?

I've been thinking about getting the book. Maybe I'll give it a whirl.

Roll over Thevenin, Norton, here we come.