Originally Posted by ruthrj
He was saying that the chassis ears have been inconclusive to date on trying to find or isolate the noise, especially on the wheel bearings. I asked him, well, since the vibration and hum is such occurring at such a low frequency, are the chassis ears even designed to detect a noise/vibration of that frequency? The frequency of the hum is so low it would likely take a subwoofer to replicate it. He responded that he honestly didn't know and wanted to ask the Field Service Engineer the same question.
You know, that may actually be the problem. Hate to quote myself, but I just had an epiphany. I've never seen or used chassis ears, but it sounded like a technician uses them with a pair of earphones. The frequency of the hum is so low I don't think earphones would be able to reproduce a sound of that frequency even if the microphone was able to detect it.....
I think a subwoofer would be needed, or a very very nice pair of earphones.
Somebody please correct me if I'm wrong: If the chassis ears were detecting said low frequency vibration, you wouldn't even know it was detecting it because earphones couldn't reproduce that sound. Voila, can't detect the hum?