Talking to people reveals, that people believe in things that marketing has unleashed and that is repeated on "YouTube & Friends" one after the other .. but still being nonsense ...
About sound holes, soundhole covers and covering the soundhole at all there are myths going round, that just show, that people have no clue of instrument physics, sonic and other other basic knowledge of their instruments.
| Every gas-filled chamber (usually air) with a hole to the outside is a Helmholtz-Resonator. |
This physical explanation (by Hermann von Helmholtz, 1859) matches with quite a lot of instruments mankind has invented.
Guitars, violins, celli, acoustic basses, contra basses, etc., etc. ...
The soundhole is what makes all instruments that match with this phsyical description a Helmholtz-Resonator with its typical properties.
Chiefly this is the Helmholtz-Resonance-Frequency that is implied with all of such instruments.
For the details of Helmholtz-Resonators see the InterNet ...
Myth #1 ...
"The sound is coming from the sound hole ..."
Wrong!
The soundhole only provides a somehow better 'bass projection' - effective only in small rooms and at small distances ...
The sound is coming from sonic that the swinging 'sound board' generates - to the outside air-space as well as to the inside air-space of an acoustic instrument ...
Sound that a human ear (or a true microphone) hears is nothing but moved air molecules that is called 'sonic'.
Myth #2 ...
"The bigger the sound hole the more bass you get ..."
Wrong!
Infact a smaller soundhole shape gets you more bass. Or did you ever see a contra-bass with a 30cm (~15 inch) sound hole diameter?
... to be continued ...
