Door speaker mounting depth
 

Anyone know what the max size I can get away with without any mods in the door would be? Also, seen a lot about 6.5s not fitting as it is.

Looking at a 6.5 component set and the woofer has a 2.9" depth

I added some really shallow mount subs in the door, and even then, I had to modify the speaker box in the door to make them fit.

How did you modify it and how did it sound?

You're running those off the stock deck and amp?

I used PIONEER TS-A1675R 3-WAY easy fit and sound great.
no mods needed, just remove door panel, unscrew old and install new.
same screw holes. if you are hooked to factory amp you will get bass only.
if no amp or a custom amp you will get full range sound.

Right, looking to get something that has better bass response than factory without changing out anything else since it's not really going to increase the value.

If you're running off the amp why did you install a coaxial?

sorry for delay, I have been away. coax allows me to go either way with/without amp.
hooked up to oe becker system for now but will be installing a new head unit in spring
and will probably run doors in full range. bass only has worked fine and really
adds sound I was missing with oe speakers which must have been bad.
found them new on ebay for under $40 without grilles/hardware which I didn't need anyhow.
very easy upgrade.