i have a '94 honda accord with 98k - runs great

i'm noticing a deep wirring / humming sound around 2000RPM
anything above or below that and the sound is gone
it occurs with or without the transmission engaged

any thoughts?
thank you!

 

Noises and location of such over the net are very hard.

Can you pull the belts, spin the pulley's (alt, ac, ps). Feel for "free spinning". You can start the car for a short period without those installed, is the noise still there?