2001 Mazda Millenia

I believe there either 5x9s or 6x9s

Basically something that sounds like a regular subwoofer.

The ones that go into the door.

door speakers aren't subwoofers and won't ever sound like subwoofers

so i'm confused as to what you are wanting...just new door speakers?

Yes

Basically upgrades. to get a louder bass

how much $ you have to spend?

do you already have an aftermarket head unit?

No clue

and about 50-100$ a pair

This post was edited by Pamida on Jul 18 2013 06:59pm

http://www.amazon.com/Rockford-Fosgate-T1682-Full-Range-Speakers/dp/B002G9DO92/ref=sr_1_5?ie=UTF8&qid=1374198783&sr=8-5&keywords=Rockford+Fosgate+T1692
http://www.amazon.com/Rockford-Fosgate-T1692-Coaxial-Speakers/dp/B002G9MHHC/ref=sr_1_1?ie=UTF8&qid=1374198783&sr=8-1&keywords=Rockford+Fosgate+T1692

on the "style" thing for the 6x9 just leave it at 2 way.

How loud will these get?

well since you haven't said if you have an aftermarket head unit or not idk

speakers don't get loud by themselves. without power they just sit there.

How do i know if i have a aftermarket head unit?

because it will be sony/pioneer etc

if it was factory it would look like some old crappy thing.