Help With a Buzzing Noise

[JCPDS3]

Hey everyone, my NSX has a buzzing sound I'm having problems troubleshooting and I hope you can give me some assistance. The buzzing sound seems to come from the door speakers, and I've noticed my stereo makes a "thump" noise when I turn the car on. The pitch of the buzzing changes by the RPM of the car, starting off low and raising in pitch as the engine revs higher. I've tried a couple things detailed below and hope you can give me some advice as to what to try next:

1) I tested to see if it were the aspirator fan even though the sound seems to come from the speakers. The sound only occurs when the engine is actually on, not when the key is set to the "ignition" setting so I don't believe it's this. I also tested the method in the wiki, which suggests starting the car, turning it off, then switching the key to "ignition" and the sound did not come back.
2) I removed the fuses for the speaker amp and the radio/center console, and the noise still occurs even after I've verified the radio is not getting any power and cannot turn on.

As a side note, my antenna also does not go up when the radio is turned on.

Thanks in advance for any assistance you can provide.

Jon

 

[Briank]

The thump noise from the speakers tells me your speaker amps are at the end of there life and need repair. If the speaker amps are powered down there is no way you are getting any thing out of the speakers. I am thinking you have an aftermarket amp?

 

[JCPDS3]

The thump noise from the speakers tells me your speaker amps are at the end of there life and need repair. If the speaker amps are powered down there is no way you are getting any thing out of the speakers. I am thinking you have an aftermarket amp?

I don't think I have an aftermarket amp. So far as I can tell, the car has a stock radio. I didn't see any amps mounted behind the seats or in the trunk of the car.

Jon