Overflow comb - noisy?!?

Hi,

Just ordering a new tank and desiding on the level my internal
overflow chamber should be built on. I'd like the water level in the
115g tank to be approximately 1" - 1,5" from the top of the tank.

For tuning and many other usefull purposes (saving fish from entering
the OF chamber) I have been planning on a comb placed around the edges
of the glass overflow. I'm worried about the possible gushing
waterfall noises the comb might make. Some 600g/h flow through. I
ungerstand, the woter runs smoother without the comb...?

What experiences you have on combs and their level of extra noise?

S