in the rear they are 6.5 inches and in the dash it is 4 inches.
The front dash speakers in the 89 Mazda b series pickup trucks are 4".
Both dash and rear panels use 4x6 in speakers
a 1991 buick skylark has 4" speakers in the dash and 6x9's in back
Attached in the links below are diagrams for the factory radio and the related dash panels to remove it. I've also posted some additional links for future reference.
For the front speakers you need to take off the dash pad and the rear speakers you need to take off the rear speaker panels.
Remove the dash pad, then remove the speakers from the dash frame. For the rear speakers, open the trunk and remove the brackets, that hold the speakers in place. not for the back speakers ..you have to remove the lower rear seat then remove the seat belts then the rear seat back then remove the header panels in the back seat then remove the deck cover ..the rear speakers are bolted in from the top down under the rear deck cover....and the front speakers i believe are mounted in the door panels in the front doors ..you have to remove the door panels to remove them .some do have them in the dash also if they are there u do as the person stated before me.
4x6" speakers in the dash. 6 1/2" round speakers in the doors and 3x10" or 3x12" in rear panels if ext cab
Remove speaker grill covers on dash to expose tweeters then remove door panels and you will se the rest of speakers
What is the size of speakers on the dash of a 1991 gmc single cab
Chevy speaker size1988 has 4x6 in both places.
Peace, The front speakers are located under the front dash panel. To gain access to the speakers you will need to take the side panels and the dash out, this is fairly easy to do. First grab the side panels near the top and pull, there are keepers holding it in and no tools are needed. Once you have one side removed go to the other side and pull the panel off. Next will be the dash and it is also held on with keeper clips. Start in the middle and pop the panel loose. At this point you should have the side panels and the dash panel removed. The speakers are held in place with Phillips screws.
4" in the dash and 5.25" in the rear panels, rumor has it that you can fit up to a 6.5" in those rear panels or a 6x9" with some trimming.