Sounds like as easy question, but.... I've got a 67 Coronet convertible. The only factory opening is one in the dash. It's got an all new interior so no hacking holes in the door panels. Has anyone done this? Under the seats? Under the dash? Subwoofer behind the rear seat? I'm thinking 4 speakers with a amp and subwoofer? Any help would be great!

Never tried them myself but another member with a 67 Coronet R/T vert was using a under seat enclosure... I think it was the one in the link below but I'm not certain..

http://www.vintagecarradio.com/store/product_info.php?products_id=12

I'm not Shure how far you want to go with it , I have a 66 coronet convertable and plan on installing a good sounding stereo but couldn't find anywhere to mount speakers. You can make a bracket and put to small speakers in the middle of the dash, I bought some used front kick panels and plan to fiberglass some wood speaker rings and finish them off really nice, bought some old beat up rear interior convertable plastic side panels and plan on doing the same with them, also a subwoofer and amp hidden in the trunk. I'm trying to do it in a tastfull way so it doesn't look out of place so no strobe or led lights flashing (pimp my ride style) my car would fit in the custom category, so if your car is all stock than I would agree that its probably not for you then I guess your best bet is the speaker that hides under your seat, but I've never heard any of them sound really good, yes you will hear some music but the quality ain't quite there.

I have a 66 Newport convertible. I mounted a 6x9 dual voice coil under the dash in the factory mount and a 5x7 dual voice coil in the middle of the back seat backrest. There was a factory spot to mount one. The speakers have two tweeters and share the bass. Not much if any seperation on the "stereo", but I didn't have to cut up any of the interior. They sound good at low power, but don't like high volumes. I plan to try adding some type of amp to see what happens. I believe they are from custom audio sounds or something like that.

I used the dual speaker replacement for a 6X9 by Custom Auto Sound in the front, standard 6X9's in the rear.

something will have to give. either sacrifice the all stock look inside, or sacrifice sound quality.

for good sound imaging, you want some tweeters that are spread out to create your sound stage. that means something on each door, kick panel, or corner of the dash...because you also want it in front of you, not behind you. rear speakers are just for "fill"

now, if you don't care about the stereo sound then some small tweeters side by side in the big center hole with a custom bracket would give sound quality without the stereo imaging, then a sub in the rear somewhere.

Best plan I can come up with so far is the Custom Autosound underseat subwoofer mentioned above (they do another model with 8" woofer) and one of these up front
http://www.retrosoundusa.com/products/details/id/68


Probably some other tweeters out of the way would help, but in a vert, with a honkin V8, sound quality IMHO is always going to be compromised!

Any more info?
I just replaced my old Pioneer Head unit with a newer JVC one in the convertible, but I still just have four used 6x9 speakers sitting on the rear floorboards.

my old skylark vert had a the 6 speakers from an old surround system hidden everywhere I could in the car and a 10" tube sub in the trunk