I posted about a wierd noise I have with an EP175 recently. I guess actually I could classify the type of noise reproduced as a buzzer probably. Do you have this noise with low volume, or only when you start increasing the volume?. For me it sounded as an air flow generated noise, as compressed air escaping quickly producing this noise.
Axiom said they are going to send me a new sub, but I have my doubts if this is a failure or a feature...