Yes the board I am standing on closes the waveguide, and yes I also have a solid version as well (no hole over the speakers), experimenting with both.
Obviously different results based on capturing sound from the back of the speaker. Closed has more bass, which honestly I don't need, because I am getting so much from the waveguides. Open is noticeably loader (can't remember dB difference). The soundboard itself will also have a version with standard hole, and no hole. Amazing how trying different combinations of both changes the volume, tone, and which frequencies levels are favored.
Again the chamber divider must be fully closed and pressed hard against the body to get great results. I am only getting some feedback from a mic, and also a little with pressure transducers when I mount them within 4" of the speakers. That is where they pickup too much vibration and feedback, beyond that no feedback. The under saddle piezo zero feedback, at least with another guitar, so not a great test, but encouraging. The "chamber divider" I am standing on is very easy to make, so I can try many different types. 1/4" Baltic Birch, just cut/sand the outside/inside shapes at home.
I want to screw this and the top soundboard onto the guitar, no glue, so they can be removed easily. This is where the banjo construction influences me, and also the soundboard/skin that moves so easily on a banjo.
Since the maple is 1/4" thick, I can easily use #5-40 stainless steel screws. Brass looks better, but not strong enough. Dovetail programming should be complete this week, pretty easy, then of course waiting for machine time at work to cut it. After that I can assemble/fit.
I don't know why I decided to stand on the chamber divider, but it is pretty amazing to feel the vibration in your legs. I know not useful, but fun! I keep telling myself bottom rigid as possible so it rings like a bell, and top as thin/strong as possible so it moves like a driver cone. Have you checked out Electrophonic Innovations with the amp/speaker in an electric guitar? What do you think? I believe the amp is rated at less than 20 watts. Thanks JJ!
Obviously different results based on capturing sound from the back of the speaker. Closed has more bass, which honestly I don't need, because I am getting so much from the waveguides. Open is noticeably loader (can't remember dB difference). The soundboard itself will also have a version with standard hole, and no hole. Amazing how trying different combinations of both changes the volume, tone, and which frequencies levels are favored.
Again the chamber divider must be fully closed and pressed hard against the body to get great results. I am only getting some feedback from a mic, and also a little with pressure transducers when I mount them within 4" of the speakers. That is where they pickup too much vibration and feedback, beyond that no feedback. The under saddle piezo zero feedback, at least with another guitar, so not a great test, but encouraging. The "chamber divider" I am standing on is very easy to make, so I can try many different types. 1/4" Baltic Birch, just cut/sand the outside/inside shapes at home.
I want to screw this and the top soundboard onto the guitar, no glue, so they can be removed easily. This is where the banjo construction influences me, and also the soundboard/skin that moves so easily on a banjo.
Since the maple is 1/4" thick, I can easily use #5-40 stainless steel screws. Brass looks better, but not strong enough. Dovetail programming should be complete this week, pretty easy, then of course waiting for machine time at work to cut it. After that I can assemble/fit.
I don't know why I decided to stand on the chamber divider, but it is pretty amazing to feel the vibration in your legs. I know not useful, but fun! I keep telling myself bottom rigid as possible so it rings like a bell, and top as thin/strong as possible so it moves like a driver cone. Have you checked out Electrophonic Innovations with the amp/speaker in an electric guitar? What do you think? I believe the amp is rated at less than 20 watts. Thanks JJ!
