Resonator guitar theory

[John]

If you treat the body of a resonator guitar like a speaker box, then plywood or laminated back and sides might be an advantage. Extending the ports or having a single port with extension could add more bass. A coaxial resonator might add top end.  Any thoughts?

[William F.Eden]

Give it a try John you never will no if you don;t I have did a lot of experments on the Insturment and have had some good luck.Bill..............

[Paul Verticchio]

The coaxial cone sounds intriguing.  Can you elaborate?

Thx,

P

[John Morton]

I went through a phase of cone research years ago.  One of my prototypes was a coaxial cone with biscuit bridge.  I used a normal 9 1/2" cone and suspended a 4" cone underneath.  I did this by putting the center screw through a small wood washer, then through the small cone, then on through the large cone and into the biscuit.  The 4" cone had no bead around the edge - no reason, it just seemed like a good idea at the time to encourage a response.

The result?  A persistent buzz.  Makes sense, thinking about it now.  I suppose if you wanted to pursue this, you could try building in a second concentric rim to support the inner cone, and devise a way for the saddle to load both cones.  Maybe a biscuit for each cone and a connecting screw (a la Dobro) to equalize the load.

You can send me a cut of the royalties ...

John

[John]

I could see a second rim working, I want to put the small cone on top but I'm not sure if that's what makes a coax arrangement work.

 I'm thinking stack 2 cones (small one on top)  on the bolt from the spider with a second set of nuts. Both cones could engage the spider and the bolt. Would the smaller cone produce more highs? I've read that the Macaferris with the internal resonator sounded good when they worked.

John as well

[John Morton]

Oh, by "resonator guitar" you mean spider system.  That complicates the picture.  Coaxial speakers have both cones fixed to separate support rims, driven by separate voice coils.  Of course you're not duplicating that system, but I don't see how you can provide rigid support for the rim of a small cone that sits between the spider and the main cone.

John II

[Russell Vance]

I was just thinking how a plywood packing crate full of car hubcaps and aluminium foil would sound.....pretty much the same I should think......Rusty (jus kiddin guys!)

[Donald A. Fortune]

Hey Rusty- I was reading a copy of Acoustic guitar magazine and there was a resonator guitar built that used an old Buick hub cap as part og the sound box so I guess you are not too far off .

Peace,Donald 

[Donald A. Fortune]

I have a plan for a resonator guitar and it calls for 1/4 inch laminated wood for the top and back so I would say its ok to use use it for that purpose.

Peace, Donald