Anyone installed these speakers? What’s the difference between the two?

 

SI are shallow mount, CF aren't.

Regardless, both are coaxial speakers and would only be used in replacing the rear door/rear side panel speakers, which I don't recommend anyway. To do things right (and inexpensively), put good components (where the tweeter is separate from the mid-range speaker) up front and don't bother with anything in the rear except for a subwoofer.

 

What speakers you recommend for the front and rear doors? I’m limited on budget so no high end stuff. If I install subs in the back doors how will the passengers hear the music?

I have Infinity reference amp (forget the model number) for the front and rear speakers and separate 12” subwoofer with Kicker amp.

 

Not subs in the back doors, in the trunk.

Passengers can hear stuff from the front just fine. Three feet further distance from the front speakers won't kill them. Either it's loud enough that it fills the cabin, or quiet so you can enjoy conversation.

I am a pretty solid advocate of the front soundstage setup - left and right up front and sub in the back. It's cheaper to build with quality components, sonically more like how you experience a concert, and music is mastered in stereo - not four-channel audio.

It sounds like all you need are front components - bridge the 4 channel infinity amp to 2-channel mode and just run a good set. For the price, I haven't heard anything close to the $180 Image Dynamics CTX65-cs. I have them in my wife's car and the much-praised $300+Boston Acoustics Pro60se in my own (both cars are G35 sedans), and the CTX65-cs's are about 95% as good with the vehicle stopped. When wind, tire and other ambient noise from the vehicle being in motion come into play, I probably couldn't tell you which is which, but the CTX65-cs are half the price (or less than 1/3rd the price from authorized dealers that will have warranty coverage).

 

The image dynamic speakers looks great. The tweeter fits where the OEM tweeter sits right now? Do I need a spacer for the door?

 

Yes, you need a spacer. The tweeter fits where the OEM tweeter does, you can either bend up the factory tweeter brackets to accommodate the new ones or just cut up some metal and make your own. You can modify the factory door speaker spacer, but I advise against it. It's cheap plastic that would almost definitely rattle with a well-powered speaker in there, plus the CTX65-cs speakers weigh a bit more, so I'd either cut your own spacers or pick up the ones made by zenclosures if you want something quick and clean.

 

Thank you for your help!!