Any science geeks here? I'm new to the resonator thing. Intuitively, I would think that the best kind of cone would be one which provided a domed chamber, so I really don't get the acoustic properties of something like the "lightning" cone, or even less something like the anglefood pan. Anyone?
This link gives the history regarding regular resonator guitars and the types of cones used
The reason for the domed design is so that the thin, fragile cone has the strength needed to take the downward pressure of high gauge strings. This was so that they gave the maximum volume possible. Now electronic pickups are easy to get, a lower volume isn't an issue if you are after the tonal quality of a reso guitar.
To use a "proper" cone needs a sound well, making sure you have the bridge position fixed at the start (unable to change it later) and the string angle balanced over the bridge saddle to stop the cone getting damaged. The cone has to be protected by a cover as it is so fragile, they are ugly and cost $$.
Many people on CBN and elsewhere have tried various items to develop their own resonator and because maximum volume was no longer a design necessity cheaper alternatives of thicker, stronger metal tried including license plates, paint tin lids, cookie tin lids, upturned pet bowls, tin cans etc. A group within CBN was set up specifically to share information on this
One of the early members on CBN (Bairfoot Cajun) produced his own hand spun cones which were thick and strong enough to not need a cover. They were built to be dropped into a hole in the box lid and so easy to use, the centre remained level with the box lid so setup of the strings was easy (see the building a dobro link above). Other designs have followed which follow the same principles.
So your thoughts are right if you are after maximum transfer of energy to give maximum volume without a pickup and amplifier. Part of the charm of CBG building is finding alternatives that will do the job, are easier to build with and are cheaper :0)
Joe, the post by David L. has a lot of good links for you. Here's some of my experiences. I first built a dog bowl resonator, which was cheap, fun to design the git, a good building experience. Sounded real tinny and muddy at the same time. I never considered it more than a novelty build after playing it a bit. I had high expectations, but it just didn't work out well for me. Others have had similar outcomes, some were much better. I've built two lighting cone reso's, and they were much better players. I probably built 15 gits between the dog bowl reso and the Lightning cone, and I think my building skills were much improved. As in the advertising parlance "your results may vary". I assume your question is a precursor to you building a reso git, so go for it. Build it as economically as you like, and prepare to learn and improve. Often the journey is more fun than the destination. Share your experience and photos, for veterans and newbies alike can benefit. Good luck.
I've tried many different resonators including pot lids and cat bowls, steamer lids, and commercial cones of different materials including, bronze, aluminum n such.,.,I found "cones" are not the only shape that works.,many people use square or other shapes of "resonators".,.,my favorite is thin steel.,.,such as a bake pan, pizza pan .,.,my absolute favorite is the toaster trays that come with counter top toaster ovens.,they fit a cigar box great.,.some are aluminum .,,.some are thin steel.,.,.oh and paint can lids and can bottoms "hammered out" work well too.,.,"bairfoot cajun" has some great examples.,.,as well as Maddog.,.,
Taking it one step further this discussion from 2012 is about the "rezobro"
To get the reso sound instead of a cone, large metal plate or bowl pickups are used to transduce the sound from the small springy metal bridge.
I built a tricone resonator last year using the bottoms of large drink cans (another in the works right now) and learned quite a bit about the concept in the process.
You can take a look at the post if you're interested, but here's my take on the resonator concept. While the cone or cones do make it a "resonator", it's not just the cone that you hear. The cone serves as the coupling to the top and "colors" the sound on the way there. Of course, the guitar materials matter some here too, but single cone, triple cones or even a paint can lid do the same thing. String vibration goes through them to the guitar.
This may be a big "duh" for everyone, but it was a minor revelation to me and changed the way I did a couple of things along the way.
Good luck with your build! Hope to see pix!