Midrange horn upgrades

The biggest improvement in the sound quality of the Klipsch Heritage series is to improve the mid-range "Squawker" horn. Here are a couple of suggestions about how to do that.

The very best option:

Totally replace the old stock exponential horn with a new printed symmetrical Tractrix horn from Dave Harris of FastLane audio!

LOOK HERE!

An economical option:

The least expensive option is to add damping material to the OUTSIDE of the midrange horn. You wouldn't think this would make any difference, but it DOES! The material is stick on asphalt sheets available from automotive parts stores like Pep Boys or AutoZone. The best known brand is called Dynamat. It helps on any horn, even the Altec VOT horns.

The aggressive option:

Make your own Bruce Edgar Tractrix horn!

The Edgar horns sound much better then the stock Klipsch squawker horns.

A free Windows Edgar horn design program.

(Click to enlarge either example)

The program is a Windows "console" program that will run on any version of Windows by simply double-clicking on it from Windows explorer. You can download it here:

TRACHORN.EXE, Version 1.8b for 32 or 64 bit Windows

Trachorn.exe program has several command line options.

• Enter a new length in Inches to see the effect on the horn throat. It's not good for anything practical as you want a perfectly square throat.
• (S)-Square adjusts the length to return to a square throat.
• (F)-File generates a text file (trachorn.txt) that tabulates the dimension X and W/2 dimensions describing the curved sides and dimensions required to make the assembly jig.
• (M)-Macro will generate a macro file for either (A)-AutoCADD or (G)-General cad to make a precise template of the curved sides.
• (Enter) will exit the program.

The program also gives the horn low end cut-off frequency and the thickness of the motor board that correctly tapers the square throat of the horn down to a round hole for the driver.

With thanks to VolvoTreter, the original article by Dr. Bruce Edgar describing his midrange horn and how to make them is available:

The Edgar midrange horn

For the nerds among us, here's the math involved:

Enlarge