Since more people seem to like this section, I'll repost here... Recently the ring terminal for my ground (sub amp) broke and I got this other weird connector that looks like an amp speaker terminal with a ring. I noticed that it sometimes starts to get really hot and causes my system to cut in and out. Also, that amp's ground is connected to the same place as my other amp's and they are touching - is that a problem also? Any advice's appreciated. Thanks!
Why use two different grounds? A common ground is one of the easiest ways to avoid a groundloop. If two grounds are used, the devices being grounded may see a different resistance. This discrepancy in resistance can lead to unwanted noise in the system. Idealy, every component in the vehicle should be grounded through a distribution block to a single point on the frame, with appropriate gauged wire of course. At the very least, ground them in as close proximity to each other as possible. just my 2 cents.
Just make sure you have a good connection to the frame. Use a wire brush to clean the area around the hole the bolt will go through. Use two star washers on either side of the bolt. If you feel your ground is insufficient, find another place for it. Where the seat belt attaches to the frame is generally a good place to put a ground if it is convienently located.