Bass Coupler Notation ( the dots )

[wirralaccordion]

Having bought an accordion with 7 bass registrations which are described in dot notation, I am anxious to know what they mean.
There are three lines within a circle ( giving four spaces ) with dots in the spaces ranging from one dot in the top space to dots in all four spaces which I suspect is equivalent to the master.
The accordion is a Brandoni Super Musette, Model 68.
For example, would the spaces be 16ft, 8ft, 4ft and 2ft?

 

[JIM D.]

https://en.wikipedia.org/wiki/Stradella_bass_system
(See register switches)

 

[wirralaccordion]

Thanks Jim. Yes, they're all there except that the soft bass/bass piano and master/bass forte registrations both have an extra dot on the middle line. I can't imagine what this dot stands for means if the dots in the spaces represent reeds!

 

[donn]

Note that in the wikipedia version, the reeds represented by a dot on a line start on a different note. Dots in spaces are octaves starting on C, dots on lines start on F#. So more generally, that round diagram with its four divisions represents a four octave stack of reed ranges, and reeds that overlap their neighbors are positioned accordingly.

 

[Glenn]

I always thought any printed notation on the bass couplers as pointless as you can't read them whilst playing. Best you can hope for are notches the you can feel. The rest is down to your ears.