Hi!
Having wires to control the elevator and side-ruder doesn't mean that you have to tighten the wires much!
I have used this technique on most of my models, F3D pylonracers, aerobatic and scale and I can assure you that all my controll surfaces are dead stiff but the wires are not particularly hard tightened, because you don't have to! Ceartainly no "twang" sound in my wires.
The clue to a strong and stiff controll surface is to use as long control horns as possible and as short servo horns as possible.
And naturally using good control linkage. See picture of the Easton aluminum arrow shaft I use in my Great Planes GEE- BEE R-2 to link both elevator halfes.Wire is thinnest possible fishing wire.
Regards!
Jan K
Sweden