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Introduction
I've been doing quite a bit (well, in fact a lot) of reading on the Internet recently about "tapped horns" and I thought I might give the concept a try by building a "proof of concept", to (1) see if actual output match the simulations and  (2) if the results were actually worth it. So, I downloaded a copy of HornResp (an application that seems to be the best utility available online for designing horns), and in trying out different alignments using a spare driver I had on hand, I came up with a related alignment that's typically referred to as a "tapped pipe".

First, a few definitions that may help to clear things up a bit...

A "tapped horn" is basically a horn that physically consists of the driver mounted part of the way up the horn, rather than at the throat as is commonly the case.  The advantages of this configuration are increased response at the low end (a lot less dependency on mouth size) and a smaller box, compared to a true horn with the same cutoff frequency.  The disadvantage of a tapped horn is lower sensitivity and power handling compared to a true horn with the same cutoff frequency due to increased driver displacement within the pass-band.

A "tapped pipe" is basically a tapped horn where the cross-section of the horn remains constant from the throat to the mouth.  An early example of a tapped pipe is the "Jensen Transflex", information about which can be found elsewhere on the Internet. Tapped pipes are a bit easier to build than tapped horns (because of the constant cross-section), but the ability to "tune" the response by adjusting the change in cross-section is lost.

• Design

• Construction

• Results (1)

• Results (2)

• Conclusions
   

• Discussion thread on the PE TechTalk Forum

Brian Steele
30 August 2009