Autocom Engine Noise

[Fullchat]

Hi. 15 GSA with Autocom SPA fitted. All hard wired. Unit fitted under rear seat tail. I've just replaced both passenger and rider headsets which have the round speakers as opposed to the oval ones. The improvement in sound quality and volume is massive.
However I can now hear the engine through the speakers. Stationary or on the move. Engine off no noise. It's not an ignition click or alternator whine. If I cup my hands over microphone it reduces. I've swapped headsets and connection leads with no change. Noise is there in either rider or passenger headsets. I've not noticed this Noise before and it's only there with an open mic. I've adjusted sensitivities and volume controls.
Spoken to Sam at Chainspeed and he's not heard of the issue. Said I would try a couple of other things to eliminate everything including checking all baffles present in the microphone. Advised me to get back to him if no improvement and he would speak with Autocom.
Anyone else noticed anything similar?

 

[madmechanic]

Stupid idea but you have not got the setting turned on so you can hear your own voice , I used to have a Starcom unit (same company) and some times
it was turn on by default I think and as well as hearing your own voice it picked up ambediant noise as well

 

[Old Den]

Had a Similar problem when changed the Auto comb to GS LC. Ended up wrapping the radio(icom)and autocom box and leads under the seat in heavy aluminium foil. Worked for me.

My radio and autocom where under the seat

Cheers D

 

[Fullchat]

Stupid idea but you have not got the setting turned on so you can hear your own voice , I used to have a Starcom unit (same company) and some times
it was turn on by default I think and as well as hearing your own voice it picked up ambediant noise as well

Thanks so far.

I don't think there is a choice to turn hearing my own voice on or off on the Autocom??? I think they call this the 'side tone'. It allows you to regulate your own voice and you can hear that you are actually transmitting.
I can hear my own voice with what I believe is the engine noise in the background. All tests carried out counting 1- 10 ( and backwards ) with engine running.

 

[vincentrapide]

I had a vaguely similar problem where road noise was transmitted via the Autocom SPA although the VOX was not triggered. Returned it to Autocom. They determined that the rider/passenger leads were faulty. Replacing them fixed the problem. I had previously tried wrapping the unit in foil as I had thought the noise was somehow being transmitted via the SPA case.
I hope this helps.

 

[ShakeyGS]

You seem to be saying that your microphone is open and picking up all ambient sounds. I'm not sure what else it would do but maybe some additional foam over the mic would help?

Some have mentioned wrapping the unit in foil. This creates a "Faraday Cage" which, as long as it's earthed, will conduct any stray electromagnetic safely away from the unit. However, back in the day when I still used Autocom, they used to supply an isolating lead that also eliminated this effect by taking out any electrical earth loops between the audio and the power systems. Might be worth investigating.

 

[Fullchat]

Just to clarify. The 'engine noise' is only there when VOX is activated it's just in the background whilst talking and then much clearer when speech has finished and before VOX cuts out. It is not there when listening to Nav or music.
I have fitted the open five mic covers although I use a a Schuberth flip front.