aubiexx

2006 Audi A3 Audi Smyphony with Bose

I have been using this as a guide: https://www.audiworld.com/forums/sho....php?t=1771631

I am connecting the high level inputs off the head unit. It seems that I have the correct positives located for the left and right rear speakers, however, I am unsure about the ground for each speaker.
This guide seems to show a single ground for each of the speaker outputs...initially, my thought is, "this can't be right!"

So, it powers up correctly, but there is barely any sound coming from the sub.

It is currenly configured with high right and left outputs connected to Line 1 and Line 2 with both grounds connected to Line 3 on the diagram.

Please send any help you may offer. Thanks in advance.