Heres an easy way. Go to crutchfield.com and use the outfit my car option. you will fill out your vehicle information and the system will tell you what size speakers you need and list all items they carry specific to your vehicle, including install kits, wiring harnesses, and speakers.
the speakers in the dash are 4x6s, the speakers in the doors are 6.75in. and the back speakers are 6x9's
4x6 in the dash and 6x9 in the rear
The 1998 Chevrolet Blazer dashboard speakers measure four inches by three inches. There is a dashboard speaker on each side of the dashboard.
The 93 K1500 Blazer has 4 x 6 inch in the dash, and 4 x 10 inch in the rear.
5 1/4" I have the same year blazer and i just replaced all my speakers. At least it's 5 1/4" for the door speakers and i can't tell but there's places in the dash board for 4x6" speakers.
Dash = 4 in x 6 in Door = 6.5 in Rear = 6 in x 9 in
5 1/4 for the back doors and 6 1/2 for the front doors. I am not sure about the dash board speakers.
The speakers i put in the dash of my 98 were 3.5 inch speakers!
The dash speakers on the 1997 Saab 900 are 4 inches. The rear speakers and rear deck speakers are 4 inches by 6 inches, and the front door speakers are 5-1/4 inches.
The door speakers are 6.5" and the dash speaker size is 4."
6x9
4x6 in the front dash