Posted a couple teaser pics on pett and fb. Thought id give you gents a bit more info on this.
My friend Mike who was vice president of SP Technology and the one who designed their waveguide milling machine, has built a new and improved version. The guide here is 10" in diameter and about 2" deep. This gave me a nice boost to about 800hz or so. Of course this means using a tweeter with the cajones and fs that can handle crossing low. So I went thru quite a few, mostly looking at the specs, purchasing a few. For this first attempt, I did not want to spend a whole lot of money either.
So I gave the Tymphany dx25bg60 4ohm version a try. With its concave faceplate, it was a bit of a challenge to mount. We have that pretty well dialed in. Not long ago we acquired a very nice selection of Corian cutoffs and are using that for various fixtures and jigs.
The woofer is a Dayton dsa270 in a mltl. Though I have not placed the batting or even added the port yet. The enclosure is just a big sealed unit in this test. Bass is still very strong to about 50hz or so. The final will have an fb of about 35 and f3 of 36 or there about. I'm pretty sure the lack of the port and fill is why I have the distortion spike at 500.
The sweeps here were taken at 100db @1m
, on the tweeter axis I've adjusted the cross over a bit more and flattened out the dip at 1k as well.