I have my mazda that I bought last year. I want to change out the speakers, but I don't know what size they are. Could anyone help? Please!! Thanks!!!

 

5X7 unless you have the Bose System, 6X8's will fit in the hole though.

 

So 5x7 non-bose and 6x8 bose.

 

As I understand either size will fit in either system.
I would go w/the 6x8's for convenience, or 6.5" components if you are will to play around a bit. It can be done as I have seen it... and stereo/amps/speakers are probably the last things on my list.

 

My brother has 6.5 X 5 infinity speakers that are just sitting in thier boxes in our basement. I would like to know if these would fit. They are 6.5 left to right and 5 top to bottom. I dont know if I'm explaining it correctly. That's what the pictures show on the box.

 

They sound like your basic 5x7's to me and should fit.
It has been my limited experience that Infinity's are jusssttt a little smaller in the cone measurement than many other speakers though, and don't usually offer a whole lotta' bass.
If you've got 'em though, you may as well try 'em. They would certainly be an upgrade in clarity over the OE's at the very least.

 

first of all before i answer your question... although everyone else has said it. wtf is a mazda3 COUPE? anyway as they all said 5x7's and 6x8s however if you have a smaller speaker it may work if you have the right fixture for it

 

I want to change my speakers in my Mazda 3 Sport edition - 07. Does anyone knows how you change it? I tried to take off the plastic shield but it got trashed.

 

Ummmm. The speaker grill (plastic shield?) is part of the door panel, therefore you have to remove the whole door panel to get to the speaker.