These are frequency response and impedance plots. They don't convey how the various diaphragms actually sound on the various
horns. They are used to aid in the development of passive filters.
Yuichi A-290, a 290hz with a hyperbolic flare - it's a clone of the TAD TH-4001
These are some of the last measurements I took. The impedance curve of the 2445 core just looked weird. I thought it might be the felt instead of the foam in the back cap so I swapped the felt 2445 back cap with the foam 2446 back cap and ended up with pretty much the same deal above ~ 500 Hz.
The 2445 and 2446 have different phase plugs but it doesn't appear that the 2446 has any better top end response.
The plots are 1/2 octave.
