Voicing a Soundboard

[TallDad71]

I know its a dark art and I know that there are no answers but ......... I want an answer.

I have build a soundboard with standard X-Brace spruce. I am pretty near my optimal point but I have an anomaly that I can't quite make sense of. The X is scalloped, as opposed to tapered with peaks around 70mm from the edge, this seems to give favourable results on previous builds. If I hold the left peak with a long clamp and tap the board I get lots of lovely and varied tones.

I deduce that this peak is happy acting as a node, which is good as it has more wood.

If I hold the other peak, the one that the tone bars emanate from, with a long wood clamp, nada, nothing, just a few dull thumps.

So I deduce that this spot is unhappy acting as a node, which is a shame as there is a lot of spruce mounting up around this point.

So I have there choices for a remedy, which would you advise?
1) If it doesn't like being still, remove some material to allow that section to vibrate a little more
2) Move material from other braces and see if that makes a more evenly responsive soundboard
3) Accept that bashing a loose board with your finger is a poor substitute for strings on a completed guitar and that it will probably be ok.

[Steve.Toscano]

In my opinion - "3".

But if you are wanting to play around and experiment why dont you try 1, and 2.

[kiwigeo]

I'd throw some tea leaves on the sound board and do some Chladni testing to visualize whats going.

[peter.coombe]

Chladni testing will give you lots of interesting information, but the difficult part is how to interpret it. How do the patterns correlate to the sound of the completed guitar? If you do get into that stuff I would highly recommend Alan Carruth's video. Otherwise "3", and read the Gore/Gilet books.