So, what are the main differences between the Bacophone offered by Stew Mac and the Dobson rings offered by Balsaam? I can't seem to find any previous threads on this...
This may be oversimplification ...
Dobson and Bacon have "similar" radial cross sections but the concavity of the Dobson faces rearward and the Bacon forward.
The shape and metal are probably the primary difference. The Dobson and Bacon rings I've seen have had significantly different profiles and they're made of different metals.
A Dobson ring is made of brass, and it bends down and away from the head towards the center of the circle. A Bacon ring is made of a steel hoop with brass spun over, and bends down at first but then it bends back up to create a "pocket" between the head and the ring. Dobson rings also tend to be shorter than Bacon, as measured from the top of the rim to the top of the ring.
Edited by - KCJones on 05/16/2022 11:58:28
Above are descriptions of the differences in design. I haven't done sid-by-side comparisons, but I have some idea of what they do to the sound, and I strongly suspect that they're very similar in that regard. Even though the metal is thin, it's a substantial flange in the radial direction. So, I imagine that they contribute similar stiffening to the rim. Likely more important is that they restrict air motion right under the head near the rim. That systematically reduces very high frequencies -- because it's at the edge that those are preferentially radiated, e.g., see http://www.its.caltech.edu/~politzer/bacon/bacon-ring.pdf for more than you probably want to know. Also, there's http://www.its.caltech.edu/~politzer/mylar-flange/mylar-flange.pdf (rather like Remo "Powerstrike" drum heads) and http://www.its.caltech.edu/~politzer/bacon/internal-res.pdf -- and even more stuff if you back up the tree to .../~politzer .
Comparing tone rings. to me, seems a little incomplete without comparing the rims they were attached to. The Dobson ring was invented prettyy early on and made for a thin rim. The Bacophone came later and was intended for a different rim and banjo altogether. While one or the other might work okay on some other banjo, it may be that the chosen ring (Dobson or Bacon) won't supply what one wishes if attached to a different sort of rim than the inventor(s) intended.
Is the Reiter “Bacophone” ring a clone of the old Bacon rings of that type, or is it Bart’s version? Same question about modern “Dobson” rings. Do the modern versions come from multiple maker?
quote:
Originally posted by Bill RogersIs the Reiter “Bacophone” ring a clone of the old Bacon rings of that type, or is it Bart’s version? Same question about modern “Dobson” rings. Do the modern versions come from multiple maker?
Bill:
Bill Rickard makes a Dobson style ring. It is sized to fit Keller drum shells which are slightly under-size (10 7/8" and 11 7/8" respectively). Dobson Tone Ring – Rickardbanjos
Pisgah banjos makes a Dobson style ring too. Im not sure of the specifications. Dobson tone ring (balsambanjoworks.com)
Bart Reiter used the Stew-Mac Bacon tone ring in his bacophone model. It is a reproduction of the Bacon FF type spun "donut" that sits on a brass hoop atop the wood rim.
Edited by - jbalch on 05/17/2022 08:29:03
Thanks, John. I’ve never had a banjo with either, hence the question.
If anyone has good set-up recommendations for a banjo with Bacon-style tone ring let me know. I have an older Ramsey with that ring and it always seemed quiet. I love it while playing alone, but it gets lost in a jam. I currently have a frosted head on it, but I have tried skin heads and Renaissance heads.
