Anyone ever installed a Quarterman QD2 cone? If so, what was your assessment of the differences in tone, power from the standard cone?
Edited by - SamCy on 06/09/2024 22:00:58
Frank Harlow installed a Quarterman cone and a #14 spider in my Regal Black Lightning which I travel with.
Much improved!
Do not know the model number.
Frank used Quarterman cones in all his guitars.
The QD2 is the only one showing as being currently available for a reso guitar from Rob @ Blue Note Woodworks in Oregon.
I have never used one of these, but the fact that he even has any tells me this style isn't particularly popular, since it has been a few years now since any new cones have been spun by John in Southern California due to equipment and supply issues.
https://bluenotewoodworks.company.site/Quarterman-QD-2-2-Step-Inverted-Res-o-Cone-10-9-16-p84148826
Interesting that the cone with the mid-radius fold was patented earlier, while the one with no mid-radius fold was patented later. As Mark points out, the earlier design is much preferred. According to the description at Blue Note, the cone with no fold has fewer overtones, like a National cone. This supports the idea that the purpose of the fold was to produce a fuller compliment of high harmonics.
Edited by - SamCy on 06/12/2024 13:02:30
I acquired and installed a QD2 to see how it sounded. I can confirm the description at Blue Note, that it is missing the high harmonics over the whole range of the Dobro that are present with the standard Dobro cone. As they said, it sounds like a biscuit-cone National.
This suggests that the mid-radius fold acts like the angled tone-bars on a steel string guitar, causing the sound board to subdivide into higher frequency modes, to better produce treble response.
