Now that I have finalized the design (almost anyway) and got into the garage to start working, figure I'd post the details up here for kicks.
B.O.T. stands for Bucket Omni-directional Three-way. It uses a 5 gallon bucket for the bass bin, and seeks to radiate almost equally in all directions. The drivers I've chosen so far:
- Woofer: Usher 8945A. I picked these up for a steal used, and have yet to try them in anything. From what I've heard of the Usher line though, I have high expectations. This driver uses the bucket for the bass bin, making it a vented 19L enclosure tuned to about 40hz.
- Midrange: Vifa TC6FC02. Tiny neo driver, I measured these a while back and they are very low distortion. They sound quite nice too. There are two per speaker in this design, bipolar arrangement. While I've not down the xo work yet I imagine they'll be covering 800 to 5k.
- Tweeter: This is the big question. It faces upward in the design, so excellent off-axis is a must. I am making a plate to be changed out, and I plan on first trying the SB19ST again. I wasn't sold on its sound in the Iron Driver challenge, but I'll give it another shot. Another possibility is the SB26STCN, which has stunning off-axis for a 26mm dome.
These are all smooth drivers, and because they will be acoustically centered/time aligned I expect a very minimal crossover network. Here is the concept:
Very nice concept. I am yet to hear any omni
The port pipes that support the mid/tweeter assembly are 1.5" PVC. Above you can see the two fittings installed into the top plate, just on either side of the mounting hole for the Usher. The whole design with be able to be broken down and moved and assembled with minimal tools. I'll be doing this at Dakota.
Maybe try the TB 13-1761s, https://www.parts-express.com/tang-band-13-1761s-1-2-silk-dome-tweeter-pair--264-841
2 pair is CHEAP!
or opposing tweeters would work.
Good Lord, this hobby always has me buying something... found this Vifa tiny tweeter at... digikey? Who knew: https://www.digikey.com/product-detail/en/peerless-by-tymphany/OC16SC00-04/OC16SC00-04-ND/6211112 *ordered*
Hmmm... nice find, JP. Has my wheels turning for sure. We had spoken in the past about the cool drivers Tymphany has made available but not necessarily through traditional outlets frequented by DIY'ers. I always thought Digikey limited themselves to shitbox speakers for computer cases and industrial beeper applications - turns out they are a Tymphany distributor as well, how cool is that?
Now we know where we can get that little Peerless woofer
Low, but not to low for most woofers these days. Specs claim 100W noise power 2.5k and up. Though I can't imagine how the little assembly could sink all that heat.