Squeak underhood

I have an annoying squeak under the hood. I replace the belt often due to the glazing and the squeak drives me nuts. This normally does it. Now it is a new belt and the squeaking is still there. Something different this time is that it doesn't go away once the car is warm. And the squeak gets faster when I accelerate, you can barely hear the squeak when idle. Is it a pulley? alternator? any help would be great.

might be idle pulley and or belt tentioner, take the belt off and rock the edge of the pulley and tentioner toward and away from the motor there should not be any play.

it might be the bearings in one of the pulleys, maybe the water pump. Next time you have the belts off spin the tensioners and see if they squeek, they might just need some grease in the bearings.