[Harp-L] low end frequencies

[Rafael Veggi <rafaelveggi@xxxxxxxxx>]

when I play two reeds at once, I notice an awful low end frequency that
comes from the harp
when I bend this double stop this monster gets shape and therefore gets
more noticeable
but when I play amplified, oh boy... it goes really nasty

I bet an equalizer would be helpful, I've never tried and would like to ask
my good fellows before buying one.
but which one? graphic or parametric?
and also Is there any tweak I could be doing in order to fix this problem?

thank you folks

ps I usually play on a sm58 straight to the mixer