speakers pulsate at any volume

i hooked up an amp for my 6X9s and, its a 20$ amp, and i hooked up all the wires correctly i thought, but when i turned on the radio all i hear is thud thud thudthud thud thud, really quick. so i turn the volume down to 0 and i hear the same, and its not fromthe speakers, its from the amp, what could be the problem? i have it hooked up with rcas, not sure if it would matter if i switched those up,

maybe, just maybe because its a $20 amp...

Are you saying your amp is making a thud noise? Please explain. Remember...you get what you pay for.

the speakers make that frequency sound, and thatswhen theradio has any other volume other thannothing, ifits at 0, i hear the same frequency coming from the amp, but much quieter

Ok maybe you ran your signal cables(rca's) too close to your power cable. You should have at least about 2.5 feet between them.

i dont know why but i have always had problems using RCA outputs from a headunit, even when i run the completely seperate from my power cables, i have had that thud sound in my subs before and i solved it by ripping an rca wire and connecting my positive speaker out put into the center wire of the rca, it works well, but who knows if its the right way to do it, im happy with it, maybe you will too, i dont know abolut your amp but i have been running mine like this for half a year and nothing has happened to it

amps don't make noise, it's impossible for an amp to make noise, there's no diaprham in an amp. sounds like you have a bad ground or bad rcas. buy some good rca's, good power cable, and for goodness sakes, spend more then $20 on an amp. good luck.