I have an infinity amp meant for a car model 610a. There is a guy in my area selling a custom built 15" passive sub for $75 in my area. From what he has told me it sounds like a decent speaker. I would check it out first of course. My question is, I would not be able to afford an amp for this but I do have that Infinity. Would I be able to use it for a home theater sub? What would I need to make this work? Thanks in advance. Here is a link the the amp I have.
The cheapest way for you to do this will be to get ahold of a free/cheap stereo receiver, maybe like one from the 90s or even older, and use that. You won't get a ton of power but you can get some bumping for cheap.
"Vintage" is good for wine, not for A/V equipment.