It's been while since I've posted any content here. Let's see if any server maintenance has made things any easier...
In another thread I posted about saving drivers from a really old pair of Monitors that had been abandoned: 4X Gauss 4385A 15" and a pair of TAD TD4001. My original thought was to recreate something like a Westlake large format 2 or 3 way design using the Gauss & TAD drivers. Then I stumbled onto a batch of TAD TW-1601a 15s and started thinking more along the lines of Exclusive 2401/TAD TSM-1 2-way systems. It's a pretty straight forward large 2-way and having built Yuichi A290 radial horns in the past nothing in the build is beyond our doing.
But being me I can't keep it that simple. For HiFi use I'm not a fan of mid horns with vanes for dispersion enhancement. The TAD TH-4003 horns are supposed to have improved dispersion without vanes. While there are pictures of them, there's remarkably little technical info or drawings available on them. And that horn is made for the smaller throat 40mm of the TD-4003.
Studying what info is available I designed an APAXIAL (Asymmetrical Pattern, AXIs And Level) radial horn based on the TH-4003 but for the larger 50mm throat of the TD-4001. I am guilty of hubris. Initial tests look pretty good. The traces attached here are raw with no smoothing. Tests are crude as I am in a civilian air traffic pattern and it's noisy here.
Based on this I now need to try to design the AFAST (Acoustical Filter Assisted System Tuning) which is really a Helmholtz resonator in the upper horn surface. While working out the general idea for this project I happened to meet a former TAD R&D engineer who is digging up some of the tech data on the TH-4003 for me...
But overall, the initial results look promising.
eso