hi guys,

i was checking out the gain-before-feedback levels of a mixer/mic
combo. i got it to where it was about to howl, and then backed the mic
input level down just a bit so it was in the "safe" zone.

then i brought up the power amp level. i thought it would tip it back
over the edge and start to get the "about to howl" situation. but it
didn't.

how come i could bring the power amp levels up more without feedback,
but if i barely increased the gain on the mic channel, it would
proceed toward feedback?

i thought once you were at the edge of feedback, any increase in gain
anywhere in the signal chain would tip it over the edge. but i seem
to have gotten away with some extra "gain without penalty" from the
power amp.

why?


my next related question is this: if you are trying to get a PA
situation set up, should you turn the power amps way up and then keep
the gain controls on the mixer comparatively low to get a better
gain-before-feedback ratio?