Since the LABhorn is a DYI project, it’s no surprise that there are at least 5 versions of Tom Danley’s baby. The earliest version dated 2/17/02 was drawn by Tom himself, and is now posted on the documents page as “labhorn1a.jpeg” and “labhorn2b.jpg” under the word HORN. While the drawings are rough, there is enough info to get the job done, but it is doubtful that anyone built a LABhorn from them.
The second version was done by Brian Fehrman, and approved by Tom. It is very professionally done, and much more complete. It is dated 4/4/02, and was used to build the first LABhorns on record. While there are several changes from Tom’s original design, none of the changes altered the horn flare enough to make any difference (IMHO). You can find Brian’s version on the documents page
At this time, we were all in “horn learning” stage, and several people noticed inconsistancys between the two versions and the table of the “perfect” horn. Some even thought that the difference between 3/4” plywood and 18mm plywood had to be reconsiled. During this stage, Peter Sylvester created a third version of the LABhorn with dados and biscuits that “corrected” both Brian’s and Tom’s versions. Peter built one LABhorn, then made more “corrections” and made a second one. Peter reported that he could measure no real difference between his cabinets and the results as reported by Al Limberg, “Too Tall” and others. While he may not have “fixed” anything that mattered acoustically, Peter’s version is the most rugged box you could build. His website has been an inspiration to many, with his pictures, drawings and explanations…Good work, Peter!
There are two other versions, and since I don’t know which one came first, I flipped a coin and Jeremy Bridge’s version is the winner. I’m afraid that the coin toss is the only thing that Jeremy wins, since his drawing has too many errors to be used by someone who doesn't have the experience to find them. It purports to be a “metric” version, but has the English dimensions as primary dimensions (but sometimes rounded to the nearest inch). While the drawing is mostly done in the U.S. standard third-angle projection, Jeremy detailed one part of the nose flare in “Dutch” projection (first-angle). There are a few lines that should be dotted that aren't (horizontal flare #1).
That brings us to our fifth version, a major revision by Brad Litz that he calls version 3. His version is for home theater sound. More like fine furniture than a “roadie proof” speaker, the compromises he made may make his version useless for pro sound. For instance, he raised the compression ratio to 3, which stresses the speaker cone. Until someone builds this version and takes it on the road, we can’t be sure the LAB-12 can handle the stress. He has posted 3-D cad files plus some detail part drawings on his website, which means you must have 3-D cad to get the info. He used Hornresp to model the changes, and seems very happy with the results… Good job, Brad!
In the end, Tom’s design is a complete success. “Improvements” by all the builders did little to damage this rugged horn. One or two piece baffle, 3/4” or 18mm plywood, 5 1/2” or 8” corner brace, different access covers … all the horns worked fine.
Tom’s Drawings @ prosoundweb
http://web1.prosoundweb.com/lsp/labhorn1a.jpeghttp://web1.prosoundweb.com/lsp/labhorn2b.jpgBrian’s Drawings @ prosoundweb
http://web1.prosoundweb.com/lsp/horn_asm_1.dxf http://web1.prosoundweb.com/lsp/horn_asm_2.dxf http://web1.prosoundweb.com/lsp/horn_asm_3.dxf http://web1.prosoundweb.com/lsp/horn_asm_4.dxfPeter’s Website
http://home.comcast.net/~labhorn/Jeremy’s Drawings @ prosoundweb
http://web1.prosoundweb.com/lsp/LAB_18mm_drawing_1.dwghttp://web1.prosoundweb.com/lsp/LAB_18mm_drawing_2.dwghttp://web1.prosoundweb.com/lsp/LAB_18mm_drawing_3.dwghttp://web1.prosoundweb.com/lsp/LAB_18mm_drawing_4.dwgBrad’s Website
http://www.geocities.com/hulkss/index