To Add Side Weight or Not?

[Mitch Lees]

I have attached the bridge to my current traditional classical build (Hauser type), and recorded a spectrum which has left me with a bit of a dilemma. By chance (!) the 2 major resonances fall nicely between scale notes: the first air resonance at 102hz falls between G and G sharp and the coupled top at 215hz between G sharp and A; however, the next major resonance which I think is the long dipole is 329hz - right on E, and then there is another reasonably strong multi-pole resonance at 392hz which is very near G. So I am not sure whether to make adjustments by adding side weight or not. Do I thank my lucky stars that the 2 major resonances are OK and press on, or do I degrade them in order to move the other 2?

Grateful for advice please.
Mitch

[Trevor Gore]

Side mass mainly affects the T(1,1)2 resonance due to the nature of the momentum equilibrium between sides and top in that mode. Side mass will have no effect on multipole top resonances as the momentum equilibrium for those modes is maintained within the top alone.

The first question when tuning modes is to ask yourself whether the notes played in that mode's frequency range are giving a problem, e.g. a wolf note. If not, don't worry about it. Multipole resonances (dipoles, tripoles, etc.) can give problems, but usually don't.

[Mitch Lees]

Thank you Trevor. I will wait until the instrument is strung up to make a final decision. However, I suppose the good thing about having built-in weight attachment points is that the decision does not have to be 'final'.

Mitch