I have had 2 different people say they can hear a high piched tone when my diesel engine is at idle or one click at speed. At higher speeds they say the tone goes away. The high pitched tone does not slowly go away with increased throttle movement. It is there, or not at all. I have the LocoFi 3 on two differnt locomotives. Same issue on both locos. I don't hear anything unusual, but the people that do hear the noise are much younger than me. Any one else have this issue?
top of page
bottom of page
This is actually our third case that someone has reported and bothersome.
What you are hearing is the base 16kHz audio that the microcontroller is playing the sounds at. It's usually not audible as it's on the borderline of human audible range. Only a select few (mostly younger people) can hear that high frequency. We conducted some in-house tests and 16kHz seems to shift higher towards 20kHz at around notch 3 and beyond making it completely inaudible to even the most sensitive human ears.
We already have this on our "to-do" list. But, now that it has been reported once again, we will give it a higher priority and see what can be done in the software to minimize it and/or if any external components (e.g. a low pass filter) can help.
Thank you for bringing it to our attention.