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  »  New  Some horn writing by Thomas Dunker. ..  Some horn writing by Thomas Dunker. ...  Horn-Loaded Speakers Forum     0  41807  01-14-2006
  »  New  Some Horns propaganda..  Old paper direct-radiation tweeters...  Horn-Loaded Speakers Forum     4  64217  07-04-2004
  »  New  An Interview With Dr. Bruce Edgar..  An Interview With Dr. Bruce Edgar...  Horn-Loaded Speakers Forum     0  54869  07-10-2007
  »  New  Battling stupid Horn Criticism as a concept..  Some Brit’s take on the Horn sound.......  Horn-Loaded Speakers Forum     32  135315  08-03-2009
  »  New  The state of High-Efficiency Loudspeakers...  Tom Danley’s brilliant law...  Horn-Loaded Speakers Forum     6  63870  02-25-2009
09-26-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 1
Post ID: 14566
Reply to: 14566
“Why horns”, years later.
fiogf49gjkf0d

Back in end of 90s, we read articles by Thomas Dunker, Joe Roberts, Bruce Edgar, and many others (some of them were designers and some of them just publicists) who were trying to persuade that horns are some kind of advantageous topology and that horns allow getting advantageous Sound. Sure, making those statements they provided various reasonings why it might be so. People who read my site know that I am not against of  the idea of horn loaded acoustic systems, still, knowing something about horns and playing a devil advocate I would debate and destroy each single reasoning that would “prove” why horns are better.

It is not that I disagree with many of those reasonings. Those reasonings and rationales are fine but if a rationale might be questioned and defeated then it is not the causality but a JUSTIFICATION FOR FATE-BASE BELIEVES. So, being a new generation after Dunkes, Robertses and Edgars, I would like to express my updated alternative vision on the subject “why horns”.

Many horns enthusiasts will be disappointed with my standing on this topic but I feel that stressing the advantages of horns is useful only in context of FULL UNDERSTANDING of the subject. Yes, in many cases horn-loaded topology as we have it today is able to deliver very much advance result but the reasons for it is not in the fundamental advantages of horn loading but in the fact that electronic industry does not have a desire to produce direct radiator drivers of sufficient quality. I am not talking in this case about high-end industry but about audio industry generally.

With loudspeaker drivers we are under umbrella of laws of physics. Acoustic pressures equal to surface by exertion. More exertion means more non-linear anomalies. They say horns are good but it is not the horns are good but compression drivers that work in minimum exertion are good. Super tight, consistently saturated, underhand gaps, limited bandwidth, super tight suspension and practically no exertion - you can’t beat it but it still has nothing to do with horn loading. Did you see the audio-Morons with their high exertion direct radiators loaded into wide-throat horns? These playbacks, with no exception, sound like a lawn mower.

So, the people who advocate horns do use horns not because they are better but because horns are a convenient remedy to the fact the no one produces direct radiators drivers at truly high level quality. There are many reasons why. The truly high level quality drivers is expensive to make and the most important no one would need them (except a few derange people like you and me). The state ordinary compression drivers is equal to the state of MP3 in digital reproduction – all people like it and general public has no understanding of how much better it might be. Sure, horns with compression drivers are at advantage but it’s in a way horns are a good crutch instead of a healthy leg.

With a compression driver we can easy get 112dB sensitivity for a narrow radiating angle.  The 112dB from 1W is about 100% of efficiency. Can efficiency and compliance to low currents be accomplished in wide angle? I see no reason why not: many harrow dedicated channels and hugely expensive drivers saturated in very small radiating area. It is very expensive to do properly and no one would need it. Still, it would make horns not necessary. In fact you can model the great sound for very, very small rooms (headphones) with existing direct radiators, have great result and no need for horns.

So, in the end: why horns? Because they are cheaper and convenient way to get better sound (if they are done properly). Still, a person shall understand that horns are not a panacea but rather a suitable remedy.

Rgs, Romy the Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
09-27-2010 Post does not mapped to Knowledge Tree
el`Ol
Posts 225
Joined on 10-13-2007

Post #: 2
Post ID: 14567
Reply to: 14566
Why "little girl"
fiogf49gjkf0d
Romy,

I hope this is not too much of a threadjacking, but I think the question is connected to yours:
Is "little girl" so popular among the owners of expensive hifi because well-earning and hard-working people prefer relaxing music in the evening or is it too painful for them to get the weaknesses of their systems revealed by more complex/dynamic/fast music?
Only in the first case you would be right with your statement that there is no interest in developing better direct radiators.

Regards,
Oliver
09-27-2010 Post does not mapped to Knowledge Tree
manisandher
London
Posts 156
Joined on 09-05-2008

Post #: 3
Post ID: 14569
Reply to: 14566
Yes, good sound is possible with DRs
fiogf49gjkf0d
 Romy the Cat wrote:
In fact you can model the great sound for very, very small rooms (headphones) with existing direct radiators, have great result and no need for horns.

Yes, this is exactly what I've attempted to do. The rooms in the UK tend to be smaller than those in NA (mine is 18'x15'x12'). Also, the whole house is made of brick and over-engineered in typical Victorian fashion. This seems to help with getting good LF even at lower volumes.

I've tried to replicate the sound that I can get from a pair of AKG K1000 headphones driven by a Berning 300B amplifier. I haven't entirely succeeded - I just can't replicate the 'sweetness' and 'colour' of the sound that I get through the headphones. But it's listenable. The closest I can get is sitting near-field in the middle of the room... but then I'd just rather use the headphones!

Mani.
10-01-2010 Post does not mapped to Knowledge Tree
Markus
Posts 68
Joined on 03-07-2007

Post #: 4
Post ID: 14611
Reply to: 14569
Well
fiogf49gjkf0d
Your initial post reminded me of this

 Romy the Cat wrote:
 Markus wrote:
I have recently been thinking about efficiency. Apart from enabling you to use low power amps, is there really any reason why high efficiency is better than low or medium efficiency, all else being equal (and I know perfectly well it never is, but let's assume it is for this thought experiment)?

It occurred to me that historically, the advantage of high efficiency drivers was that they tended to be optimized for low mechanical loss. Low mechanical loss tends to make the sound cleaner, more detailed and more "free" than from drivers with high mechanical loss, a chassis designer told me. It is now possible to buy normal efficiency drivers with low mechanical loss. So, is there a reason to put up with the demands of hi-eff drivers anymore?

Actually if I have time I would probably write up MS Word’s 4-5 pages long of articles with arguments WHY high efficiency is conceptually better and why any extra dB is juts at opportunity. The way to get and the way to use high efficiency is another subject but with all things being equal higher efficiency is better. It is a bit unpleasant that high-fight industry (here I come again!) did not advance the subject and education of public about high sensitivity because they do not do high sensitivity. The industry deployed to public bogus theory about relationship between efficiency and power of amplification and everyone feels settled.

Do not be mistaken – the high efficiency itself is not a cure-all solution and it does not resolve all problems -rather creates them. Still, there are so much “new” this that is “possible” at high efficiency! Regardless the design of your car a high octane gas will prose better drive, will it?

The Cat


I'm interested in your latest thinking.
10-01-2010 Post does not mapped to Knowledge Tree
jessie.dazzle


Paris, France
Posts 456
Joined on 04-23-2006

Post #: 5
Post ID: 14616
Reply to: 14611
Power-to-weight
fiogf49gjkf0d
Romy wrote:

"...a chassis designer told me. It is now possible to buy normal efficiency drivers with low mechanical loss..."

Sure it might exist, but I question the application.

First, a bit of the obvious:

Consider only the driver; not the amps and related gear.
 
What is necessary to make a high-efficiency driver?
 
There is only one answer; a high power-to-weight ratio; i.e., a strong motor as compared to the weigh of the parts it must move.
 
If drivers now exist offering "low mechanical loss", but are still of average efficiency, then logically they have an average power-to-weight ratio; meaning one of the following: 
      
      1) Weak motors with light-weight moving mass 
      2) Strong motors with heavy moving mass
 
Both would result in what we might call "average performance".

One might argue that N° 1 (low moving mass with a weak motor) is better, but if the motor is weak, the mass won't move.
 
Mother nature cannot be cheated.
 
To understand why a good Power-to-weight ratio is desirable, consider the following automotive analogy (for some, this too will be obvious):

Think of the wheel of a large truck rolling on a cobblestone street at 50 mph. Because it is heavy, the wheel will follow the major (large-scale) variations in the road surface, but will bridge across or average out the minor variations. Also, having greater inertia, this wheel will tend to continue reciprocating against the vehicles suspension, which because of this, will have to incorporate more substantial damping; thus further impairing the wheel's ability to "react" and accurately follow the surface of the road. Heavy wheels tend to "write" their own road. The vehicle itself must also be heavy, or it will simply not offer a stable reference point against which such a suspension can work, in which case the entire assembly would shake to pieces whatever it might be carrying (occupants or freight). This in turn implies stiffer springs, further impairing the wheel's ability to "react".

Why is it desirable that a wheel remain in constant contact with the surface of the road? Because it will at some point be necessary to slow (apply the brakes), accelerate, or alter the course of the vehicle in motion, all of which require that the wheel remain in contact with the road. 
 
Now think of a wheel on a normal passenger car, which by comparison is light-weight; this wheel will follow the finer irregularities, and because it has far less inertia, will not require excessively stiff springs or overly firm dampers.
 
To bring this back to drivers:
 
The irregularities in the road are analogous to detail in sound.
Wheel mass is analogous to the moving mass of a driver.
Vehicle weight is analogous to mass and robustness of driver enclosure and driver chassis. 
 
Horn-loading:

If high-efficiency drivers are desirable, horn-loading takes it all one step further. Horn-loading is literally a series of physical levers wich allow getting work done via reduced effort. Translation: Low-excursion, small-diameter diaphragms; two things that contribute significantly to low moving mass. Getting the same work done via direct radiators is possible, but it requires working the lever from the other end; either by increased effort (excursion), which unfortunately automatically implies much higher piston speeds and the consequent need for greater damping, and loss of detail, or by breaking the work down via increased surface (greatly multiplying diaphragm area; i.e., multiple drivers), which unfortunately means multiple point sources.

To bing it back to automobiles:
 
A horn-loaded driver is analogous to a small-displacement automotive motor coupled to a multi-ratio gearbox, wich is in turn coupled to the driving wheels.
 
A direct radiator is analogous to an internal combustion automotive motor, having its crankshaft directly coupled to the axle of the driving wheels. A vehicle of this sort using a small-displacement motor would have dismal performance. If good performance is the objective (good acceleration and good top speed without a gearbox), the vehicle would have to work the lever from the other end, by using either a very large motor (inefficient and heavy), or by assigning the work to multiple, small-displacement motors (very large and expensive vehicle).
 
In automotive applications, electric motors, having constant torque regardless of rpm, are able to directly drive the wheels while offering good (even blistering) acceleration and top speed, but the acceleration comes at the expense of energy debit, which in the case of an automobile translates as reduced range. Most still do use a gearbox of some sort.

jd*


How to short-circuit evolution: Enshrine mediocrity.
Page 1 of 1 (5 items) Select Pages: 
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Some horn writing by Thomas Dunker. ..  Some horn writing by Thomas Dunker. ...  Horn-Loaded Speakers Forum     0  41807  01-14-2006
  »  New  Some Horns propaganda..  Old paper direct-radiation tweeters...  Horn-Loaded Speakers Forum     4  64217  07-04-2004
  »  New  An Interview With Dr. Bruce Edgar..  An Interview With Dr. Bruce Edgar...  Horn-Loaded Speakers Forum     0  54869  07-10-2007
  »  New  Battling stupid Horn Criticism as a concept..  Some Brit’s take on the Horn sound.......  Horn-Loaded Speakers Forum     32  135315  08-03-2009
  »  New  The state of High-Efficiency Loudspeakers...  Tom Danley’s brilliant law...  Horn-Loaded Speakers Forum     6  63870  02-25-2009
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