help with ground for system

[1990crx]

i have a system in my car. just put it in my 89 crx and i wanted to know where i should put the ground at cuz i am getting bad feedback.

 

[1990crx]

any one at all. plz help
i need it

 

[Beelzebubba]

On a CRX I am not certain but usually in the spare tire well there is a bolt poking up from the floor.

It is there you will find your ground Lemmywinks.