Most hondas, including my Integra, have 5.25" paper cone speakers
installed on the front doors.  They are normally super shallow, and
covered with a plastic shield on window side of the door to shield the
driver from moisture.

Most if not all cut through or remove this plastic shield.  If your
drivers are still too deep, it is normally very easy to make an 0.5"
MDF baffle that is installed on the door, and then the speaker on the
baffle.  This gives the speaker depth, as well as allows you to
install larger (ie 6.5") drivers.

It's best to pop the door panel off and see what you have to work
with.

Gordon

I have not installed Infinity speakers in an Accord, but I have
installed 6.5" Sony speakers in a Civic. The holders in the front doors
were too shallow for the speakers, but I was able to get a pair of
adapter rings that moved the speakers out about 4 mm. I got the adapter
rings at a local car stereo place, and I think I paid $5 for the pair.
On my car there was plenty of space between the speakers and the speaker
grille in the door, so moving the speakers out a bit did not cause any
problems.