the push Spring terminal broke off of my SA-12. Can I just use a small bolt and put ring terminals on the speaker wire or do I hand to order another push connector?
You can order those terminals from a couple places online. Can't remember where I've seen them recently but I have. If you strike out I may have a spare Sundown push terminal here though I'm not sure if SA series uses the ones I have. It may be tricky to get the nut back on the post tight with the sub assembled though.
Alternately with some patience and a steady hand you may be able to get what's left of the old terminal out of the hole in the frame and solder some 8 gauge cable directly onto the tinsel. Be sure you use some zip ties and/or glue to keep it tight in there though.