Just partially installed my new HU today after going thru 3 sets of adaptors that were WRONG

Finally after 3 trips to the stereo shop got the right ones and installed the new unit. Problem is that I seem to have a constant minor distortion sound even without any music playing

Oddly enough I found that there were 2 wires that needed grounding - one for the main power supply and the other came off the speaker bundle of wires

Since I only had one pre - exisisting ground - I grounded the main ground & speaker ground together to the factory ground off my power adapter connector

I am wondering if that speaker ground should have been grounded seperately The first two connectors did not even have a seperate speaker ground on the connector !

Also in order to power the factory amp - I had to use the attena pwr wire as there was none for the amp. Maybe I should have ran that with the main pwr supply for the HU ??

Any help is appreciated