The first crossover that actually measures

Copying a crossover from a thread is how you get a speaker that “sounds fine” and measures like a comb. This is the first filter you should build if you want the loop: model → cut → sweep → tweak.

Pick one published two-way with a documented target and a known baffle. Buy the exact drivers if you can; if you substitute, start over in the model. Do not “close enough” a tweeter with a different Fs and call it the same network.

Build the network on a board with screw terminals before you solder a museum piece. Sweep at 1 m, 0° and 15°, then look at the reverse-null. If you do not get a null, the polarity or acoustic offset is wrong — not your “room.”

Change one value. Sweep again. Write the date on the board. That is the whole editorial policy for this site: if you cannot show the before/after, it is not a build note.

When the curve is close, then talk about finish and stands. Paint does not fix a 6 dB hole at 2.8 kHz.