making wooden sounding blocks for hitting with gavels

[Robert Haines]

This probably counts as one of the odder projects ever posted on MIMF, but here goes: I'm a Freemason and we use gavels on sounding blocks to mark certain points in the procedures of our meetings. Typically, the three officers of a Lodge use solid wood sounding blocks more or less 6" in diameter and 1" thick, of solid wood such as oak, which produces a sharp, bright tone.

I want to make new sounding blocks for the Lodge I'm currently the Master of, out of some beautiful old-growth, quarter-sawn, clear-heart redwood planking that's just come into my possession, which is about 7/8" thick by 15" wide and 16 feet long. The effect I desire is a deep, resonant tone rather than the as a solid sounding block produces. I'm thinking that the design of a slit drum might be effective, but I'd be interested in anyone's thoughts.

[Bryan Bear]

No idea really, I would guess that the small size of the block contributes more to the bright tone than the actual materials used. Think of marimba bars getting longer as the tones get deeper. I would also expect redwood to get dented more easily when pounding it with a gavel.

[Robert Haines]

...I would guess that the small size of the block contributes more to the bright tone than the actual materials used.

Yes -- the size, and the fact that sounding blocks typically are solid, resting directly upon a podium. I would expect that even the most resonant tonewood like rosewood would still just produce a sharp, bright tone, if it was resting flat atop a surface. I should've pointed out that, like a slit drum, I want to build hollow boxes with the tonewood on the top, using the chamber below it to produce resonance from the bottom of the tonewood.

These are the variables that I'm uncertain of:

* Should the tonewood striking surface be attached to the resonant chamber on all 4 sides, or just on one, so it can vibrate freely?

* How large should the tonewood striking surface be to produce the optimal tone? (I would assume that the larger it is, the deeper the tone.)

* How large should the resonant chamber be to produce the optimal tone? (Again, I would assume that the larger it is, the more resonance would be produced.)

* How would openings in the resonant chamber affect the tone produced? In other words, if the only opening was a slit along the 3 sides, would the sound be significantly different/better/worse than if say, one or more sides of the chamber were open?

* Are there any finishes (say, tung oil, wax, shellac, etc.) that might be applied to any surface which would affect the tone, as opposed to all surfaces being left unfinished?

Think of marimba bars getting longer as the tones get deeper.

Right, or slit drums.

I would also expect redwood to get dented more easily when pounding it with a gavel.

True. But we don't whale on them; we just strike them with the face of a gavel to produce the desired sound. I figured that I'd need to demonstrate the new ones to the two other officers who use them, so they could get a sense of how little impact was necessary to produce the desired volume.

[Bryan Bear]

I have no answers to those questions but I do hope you post back with your results!