I looked around and settled on the Hi-Vi B4N woofers because of their low cost and good looks, the bronze cones representing quite a departure from the traditional black paper or polypropylene ones. The response graph of the B4N looks pretty ragged beyond 3KHz, so that frequency will be the determining factor for the crossover. Next, I picked the TN25 tweeters because its cost relative to its features: shielded neodymium magnet and ferrofluid for a mere $8.28. I feel that this tweeter is a good match for the B4N, since a crossover frequency of 3KHz represents one octave over its resonance frequency of 1,500Hz. I also particularly liked the idea of using square tweeters to put my wood working skills to the test.