giovedì 12 marzo 2009

Questi sono alcuni scritti del Dott Edgar


The Edgar Midrange HornPage 01, JPG, 226KB Page 02, JPG, 352KB Page 03, JPG, 302KB Page 04, JPG, 207KB Page 05, JPG, 255KB Page 06, JPG, 297KB Page 07, JPG, 280KB Page 08, JPG, 298KB Page 09, JPG, 291KB Page 10, JPG, 280KB Page 11, JPG, 324KB Single file, all pages, PDF, 9.6MB
Reprinted, with permission, from Dr. Bruce Edgar and Speaker Builder, Issue 1, 1986, p.p. 7-17, of Speaker Builder magazine.© Copyright 1986 by Audio Amateur Corporation. P.O. Box 876, Peterborough, NH 03458, USA. All rights reserved.

The Show HornPage 01, JPG, 314KB Page 02, JPG, 281KB Page 03, JPG, 314KB Page 04, JPG, 235KB Page 05, JPG, 335KB Page 06, JPG, 140KB Page 07, JPG, 361KB Page 08, JPG, 373KB Page 09, JPG, 356KB Page 10, JPG, 404KB Page 11, JPG, 377KB Page 12, JPG, 310KB Single file, all pages, PDF, 11.9MB
Reprinted, with permission, from Speaker Builder, Issue 2, 1990, p.p. 10-12, 14, 16-20, 22-23, 75, of Speaker Builder magazine.© Copyright 1990 by Audio Amateur Corporation. P.O. Box 876, Peterborough, NH 03458, USA. All rights reserved.

The Monolith HornPage 1, JPG, 254KB Page 2, JPG, 282KB Page 3, JPG, 245KB Page 4, JPG, 387KB Page 5, JPG, 396KB Page 6, JPG, 323KB Page 7, JPG, 271KB Single file, all pages, PDF, 6.9MB
Reprinted, with permission, from Dr. Bruce Edgar and Speaker Builder, Issue 6, 1993, p.p.12-14, 16, 18, 24-25, of Speaker Builder magazine.© Copyright 1993 by Audio Amateur Corporation. P.O. Box 876, Peterborough, NH 03458, USA. All rights reserved.





Un intervista

Edgar Interview, PDF, 330KB
An interview that "Audio Minister Plenipotentiary" Dave Glackin did with Dr. Bruce Edgar. Even though it's pretty dated it's also a must read.

Altri articoli

The Dinstale Horn Loudspeaker Design Articles
Three articles summarizing the development of the design theories and concluded with two systems for construction by J. Dinsdale. Reprinted from Wireless World, March 1974.
Also an interesting article to read which is being refered to very often. However, as Dr. Bruce Edgar already pointed out on AA, it's loaded with wrong headed ideas. He wrote me that he will perhaps write an critique which I will add here.
Here is the link to his posting on AA. Or read this quotation:
The first wrong assumption is the use of any old driver in a horn. He used KEF drivers which are mass loaded. If you place these drivers on a horn, you lose bandwith. Notice that he does not present any frequency response plots.The second wrong assumption is the design of a tractrix bass horn. It's an contradiction in terms. You can't get bass out of a tractrix design.The third wrong assumption is bad things happen at the flare cutoff so Dinsdale says to back off by 20% the flare frequency. Some software out there uses this assuption. You plug in a frequency but you end up with a horn of lower flare frequency (20% below) that is longer than you need. But even worse, the mouth size is calculated for the input frequency, not the lower value. So the end result is a lower flare rate and a longer

Horn Loudspeaker Design Part 1, PDF, 881KB
"Horn Loudspeaker Design", by J. DinsdaleReprinted from Wireless World, Mar 1974, pp. 19-24.© Copyright GM Media Corp., 5201 Blue Lagoon Drive, Miami, FL 33126, USA. All rights reserved. Horn Loudspeaker Design Part 2, PDF, 1426KB
"Horn Loudspeaker Design - Part 2", by J. DinsdaleReprinted from Wireless World, May 1974, pp. 133-138.© Copyright GM Media Corp., 5201 Blue Lagoon Drive, Miami, FL 33126, USA. All rights reserved. Horn Loudspeaker Design Part 3, PDF, 971KB
"Horn Loudspeaker Design - Part 3", by J. DinsdaleReprinted from Wireless World, Jun 1974, pp. 186-190.© Copyright GM Media Corp., 5201 Blue Lagoon Drive, Miami, FL 33126, USA. All rights reserved.

Alcuni piani per costruire un subwoofer

Plans
Eminence Tapped Horny
Plans of the Eminence tapped horn, AutoCAD 2000 format, 110KB Plans of the Eminence tapped horn, PDF format, 70KB
It's a large 20Hz tapped horn for 15" drivers. Suitable drivers are the obsolete Eminence EPS15-500 and the current Kappalite 3015LF, DEFINIMAX 4015LF or MTX Audio T7515-04 (many others will work as well).


30Hz Tangband Tapped Horn
Plans of the mini Tangband tapped horn, AutoCAD 2000 format, 200KB Plans of the mini Tangband tapped horn, PDF format, 130KB
It's a small tapped horn for a 6.5" Tangband W6-1139SC or W6-1139SG.


38Hz Tangband Tapped Horn
Plans of the mini Tangband tapped horn, PDF format, 310KB
It's my second Tapped Horn for the 6.5" Tangband W6-1139SC or W6-1139SG

e come costruire una tromba tactrix

Tractrix Horn CalculatorTractrix Horn Calculator v1.3a, 321KMB Tractrix Horn Calculator v1.4b ⇐ Beta Version! with some new features, 372KB
Here is a (at least for me) very helpfull tool to calculate and design straight round and rectangular Tractrix horns as well as Hypex Horns. A "filter section" is currently under construction.It's throat calculation is based on the "Show Horn" article and the tractrix formula is from the Edgar Midrange Horn article. Both articles written by Dr. Bruce Edgar for the "Speaker Builder Magazine" (articles see below).
I included some helpfull functions to easily create script files to draw the tractrix curves in AutoCAD (TM). You just have to copy a column to a test file with the extension *.scr. Then execute the so called script file in AutoCAD. Be shure to swich off "ortho" and "osnap" before. This sometimes causes strange results.
If you have problems understanding what I did or what this spreadsheet is able to do for you don't hasitate to contact me.