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Hard to believe the summer is wrapping up and we are already in the month of August.  Fall is just around the corner.  An important part of American culture during the fall is football!  Soon, teams will take to the field to the sounds of cheering crowds, bands, cheerleaders and for some, music and play by play through a brand new Danley sound system.  Check out this newsletter to read up on one such school.  You can also find the usual monthly amp article and the latest in Doug Jones' biographical series on the great personalities in the field of electronics.  Enjoy!

SPRINGFIELD, TENNESSEE – JUNE 2018: The Yellow Jackets football team is the pride of Tennessee's Springfield High School, but until this season, the team hadn't played a proper home game in 35 years! All of its "home" games actually took place at Springfield Middle School because the high school had no football stadium. But that's all changed now with the completion of a new 2,100-seat stadium right on the high school's campus. What's more, Springfield went from no stadium to a state-of-the-art stadium with "college stadium sound" supplied by just two Danley Sound Labs GH-60 Genesis Horns and a Danley TH-115 subwoofer.
System Integrations, Inc. is a Tennessee-based integration firm with broad expertise in IT and related technologies, and it has a history of successful projects with Robertson County Schools, the district to which Springfield High School belongs. "Springfield High School really wanted to showcase its new football stadium. It had been such a long time coming – and with the help of James Marshall, Robertson County Schools’ supervisor of technology, the stadium finally was completed.” explained Jeff Ledford, president of System Integrations, Inc. "Danley has been our go-to loudspeaker manufacturer for a while now. Danley boxes have excellent pattern control, fidelity, and reliability. They're very flat, and straight out of the box we get good, crisp, clear sound that doesn't require very much in the way of DSP. Moreover, Danley boxes are pretty forgiving, which is great because none of the school staff who will be using the system are audio experts. Danley gives them a pro sound without requiring a pro on the staff."
The system that Ledford designed and that his company installed is wondrously simple. For full-frequency coverage, two Danley GH-60 Genesis Horns fire from either side of the large scoreboard in the end zone, one covering the home side and the other covering the visitors side. "We've tried a lot of different loudspeaker manufacturers and models over the years, and the Danley GH-60 Genesis Horn gives us the most consistent, even coverage," Ledford said. The GH-60 Genesis Horn combines several of acoustician Tom Danley's patented technologies to deliver phase-coherent audio in such a way that fans not only get high-fidelity coverage, they also get even SPL coverage, thus delivering, via Danley's point-source technology, on the promise of line arrays without the nasty comb filtering and other side-effects that are inherent to line array technology.

In addition, a single Danley TH-115 subwoofer fills out the low end with honest, undistorted bass. "The system sounds great and everyone at Springfield High School is pleased with the results," Ledford said. "This is not a typical high school sounding football field system. It sounds like something you would hear in a college stadium.”

Genesis Horn White Paper

Georg Simon Ohm
Prof Doug Jones

This is the third installment in our series about great men whose names we know, yet we know very little about them.  This month we are going to meet Georg Ohm, who played a very important role in understanding and defining the law that governs the most basic behavior of electricity in a circuit.  Again, as we have done before, let's take a look at the unit that bears his name, the Ohm. The rigorous definition of the Ohm is:

The ohm is defined as an electrical resistance between two points of a conductor when a constant potential difference of one volt, applied to these points, produces in the conductor a current of one ampere, the conductor not being the seat of any electromotive force.[1]

So, what does this mean in plain English?  Let's revert once again to our admittedly imperfect water analogy.  We have seen that the volt is like the pressure or potential energy present in a huge tank of water on the top of a tower.  Current is like the water flowing from the tank through a pipe.  In this analogy, the Ohm would be the resistance to that flow of water.  We could think of the size of the pipe as a way to understand the role of resistance in electricity.  A high resistance like many millions of ohms (megaohms) would be like a pipe with a very small diameter, like maybe a drinking straw.  Even though there may be a huge mass of water in the tank, the diameter of the straw will limit how much water will flow.  Low resistance, like 1 or 2 Ohms, would be like a very large pipe with a 20 foot diameter that would permit a huge amount of water to flow.  Next month we will meet James Watt whose name is associated with power.  Think about how much work could be done with the water coming out of a straw vs a 20-foot pipe!

Georg Ohm was born in Germany in 1789.  Ampere was 14 yrs. old, and Volta was 44.  In 1789, the Revolutionary War had been over for seven years and George Washington became our first president. Benjamin Banneker and Pierre Charles L’Enfant began to lay out the City of Washington DC.  July 14 1789 was Bastille day, the day the French revolution began with the fall of the Bastille prison.  Beethoven, Haydn and Mozart all wrote significant works in 1789.  In Africa, the Atlantic slave trade was booming and the devastation it caused was felt deep in the interior of the continent. In China the Qing Dynasty was emerging as the most effective and most powerful in the history of China. The first European settlement in Australia was a year old.  This was the world that welcomed Georg Ohm on March 16, 1789.  His father, Johann Wolfgang Ohm, was a locksmith and his mother, Maria Elizabeth Beck, was the daughter of a tailor.  Georg was the firstborn of 7 children, only 3 of whom survived to adulthood.  His mother Maria died when Georg was 10 years old.   Neither of his parents was formally educated, but his father, Johann, who was self-taught and very well read, was able to provide Georg and his brother Martin with an excellent introduction to physics, mathematics, philosophy and chemistry. Even though Johann was self-taught, he understood the value of a good education and eventually sent his 2 sons to the local school.  The boys excelled in mathematics and physics and they caught the attention of Karl Christian von Langsdorf, a pre-eminent mathematician, geologist, natural scientist and engineer who had been appointed as the Chair of Mathematics.  Von Langsdorf predicted that the brothers would eventually become as famous as the Bernoulli brothers. This prediction was, of course, to come true.  Martin Ohm became a well-known mathematician and Georg was immortalized with his formulation of Ohm’s Law and the unit of electrical resistance, the Ohm.  Von Langsdorf convinced Johann Ohm to send his gifted sons to University to continue their education.  Georg earned his doctorate from the University of Erlangen on October 25, 1811 at age 22.  For the next 6 or 7, years Georg held a number of teaching positions in Germany and Switzerland.  In addition to his teaching, Ohm was an avid experimenter and was fascinated by the behavior of current in a wire.  He observed, mostly with equipment of his own design, that the current in a conductor was directly proportional to the difference in “potentials” between its ends.  He also demonstrated that, with the same difference in potential between the ends of a conductor, the current flowing in the wire was inversely proportional to the resistance of the conductor. In other words, I = E/R,  where I stands for current in Amperes, E stands for  Electromotive Force in Volts  and R is the  resistance.  This is what we now call Ohms law.[2]

In 1827, Georg published a paper entitled Die galvanische Kette, mathematisch bearbeitet (The Galvanic Circuit Investigated Mathematically) in which he described in great detail his observations and the mathematical support for his conclusions.  Amazingly enough, this publication was met with a great deal of criticism, and ultimately Ohm lost his teaching position when the Minister of Education declared “a physicist who professed such heresies was unworthy to teach science”.[3]  This rejection by the scientific community affected Ohm deeply and for the next five or six years he had trouble finding work and lived in abject poverty.  Finally, in 1833, the government in Bavaria offered him the position of Chair of Physics in the Polytechnic School of Nuremberg.   Gradually his work began to find some acceptance, and by the end of 1841 he was recognized for his work by the Royal Society of London and was presented with the Copley Medal; 47 years after Alessandro Volta received the same honor.  Ohms citation read “for his researches into the laws of electric currents contained in various memoirs published in Schweiggers Journal, Poggendorffs Annalen and in a separate work entitled Die galvanische Kette, mathematisch bearbeitet.”[4]  

Georg Ohm died suddenly on July 6th 1854.  Dr. Lamont, the Conservator of the Royal Observatory in Munich, said, “So ended the noiseless career of a simple, modest and highly[5] gifted man who lived only for Science”.  

“Ohm never sought for, nor did he find, fame and fortune that many believe is the only path to happiness…. He lived only for science and the love of truth and desire for knowledge.  Ohm was fond of solitude and contemplation.  He never married and lived a simple, self-dependent life”[6]

The practical unit of resistance, the Ohm, was officially adopted in 1867, to honor the man that put it all together.  Ohms law is really the starting point for every student of electronics and governs the behavior of every electronic circuit.

[2] J. Munro Pioneers of Electricity  London, 1890 page 180
[3] Ibid page 181
[5] J. Munro Pioneers of Electricity  London, 1890 page 183
[6] ibid
DNA 5k4c, The Little Workhorse of the DNA Family
By: Josh Millward
It is easy to get distracted by big numbers. After all, big numbers are impressive! That is why they are big. So, it is easy to let the DNA Pro series amplifiers steal all the headlines with their impressive power capabilities and compact dimensions. It is all too easy to forget about the DNA C series products. 
Currently, the DNA 5K4c is the only model in this series. It is geared more towards the installation and contracting market with no controls on the front panel aside from the power switches. The DNA 5K4c offers the following power output capability:
8 Ohm: 450 Watts per channel
4 Ohm: 800 Watts per channel
2 Ohm: 1,250 Watts per channel
These power ratings are considerably more modest than the flagship DNA 20K4 Pro amplifier, but to be honest, not all loudspeakers require that much power to achieve the required output. The new Mini 180 (which was just introduced in last month’s newsletter) is a great example of a loudspeaker which is well matched to the DNA 5K4c amplifier. The Mini 180 presents a load of 4 Ohms to the amplifier, which means the amplifier is capable of up to 800W of output. The Mini 180 is capable of sinking 500W, so the limiters in the preset are adjusted to accommodate this. Also, the DNA 5K4c amplifier has all the necessary DSP filters on board to provide the prescribed equalization and processing for all our loudspeakers. Pairs of output channels may also be bridged on the DNA 5K4c amplifier for higher output when used with larger loudspeakers. The DNA 5K4c amplifier also features USB connectivity to the computer, individual presets and configurations for the attached loudspeakers, and a BvNet port to connect additional DNA 5K4c amplifiers for control. 
The current version of System Engineer is 7.00.15. This version is available for download from our website:
The current version of firmware for the DNA 10K4 Pro and DNA 20K4 Pro amplifiers is 1.306.
The current version of firmware for the DNA SC48 is 1.394.
Loudspeaker Master Preset Stack version is 20170424
The firmware and loudspeaker presets are included in the System Engineer download zip file for System Engineer 7.00.15.
DNA product videos can be found on our website:
Danley Rental Gear: Got some? Need Some?

Got Danley gear that you would rent out to others?  Want people to know how to find you?  Go to the Danley rental page and fill out the rental submission form.  We'll add you to the map! 

Do you have a special gig coming up where you need a great Danley system but don't have all the gear you need?  It's possible that there is rental gear available in your area.  Check out the rental map on our website to find out where you can rent the Danley system of your dreams. 
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