I was not sure where to put this since I have no current intention to build this. But you never know. If anything, it serves as a way to document in case I change my mind. Lately there has been a lot of talk about big and sensitive speaker builds. This because it is felt that these speakers are more linear and have much higher dynamic range than smaller less sensitive ones. I believe there is some truth to this. But for me the picture was incomplete. So I decided to design a large speaker with relatively high sensitivity. Right of the bat I found that it is hard to find even "pro" woofers with more than 101 dB sensitivity. Here is a list from Eminence which includes 18" monsters: https://www.parts-express.com/pedocs/buyer-guides/eminence-loudspeaker-selection-guide.pdf However, it is not hard to find a silk dome tweeter half-assed horn loaded that will reach 98 to 99 dB sensitivity for next to no $: https://www.parts-express.com/peerl...dymium-tweeter-with-waveguide-4-ohm--264-1390 In general, I've found that tweeters exhibit much higher sensitivity than woofers, even w/o consideration for baffle step. Anyhow. I also feel two way full range speakers fall behind in the mid-range, and so I decided to design a 3-way. This is what I felt seemed like a nice mid: https://www.parts-express.com/emine...-sealed-back-midrange-speaker-driver--290-661 It's got the sensitivity, and is sealed, which means there is no need for a mid-range dedicated internal box. Here is where it gets interesting. For the low frequencies I found this for little $: https://www.parts-express.com/goldwood-gw-1258-12-pro-woofer--290-382 The Goldwood is not only an inexpensive 12" PA. It may be able to cover sub-bass with high sensitivity. There is a catch, and I'll talk about it later as we go along.