Dayton ND25FW

dcibel

These aren't my measurement, just sharing some data that someone else has shared with me.

ND25FW is a low cost dome tweeter with a nice small waveguide. As of today, it's cost is USD$22 making it one of the cheapest waveguide tweeter options available.

It was installed in a bookshelf cabinet along with a SB PFCR series woofer:

Measured frequency response is very promising.

You may be concerned that the high Fs of ~1400Hz is a problem, but it is a fairly small peak as this tweeter uses ferrofluid:

For a basic crossover example, a simple 2nd order filter was built.

And here's the transfer function of that filter. As you can see, the impedance creates a bit of a bump in the knee of the response, but not enough to be too concerned about, especially at $22.

dcibel

Screenshot of the crossover got shrunk down. If you can't read it, it's a 10uF cap and 0.25mH inductor.