Jensen Speaker Date Codes
There is an easy way to determine the date of your vintage Jensen speaker. On the edge of the speaker where the mounting holes are there will be a six digit number. The first three numbers will be 220 which denotes the manufacturer as Jensen. The next number is the year of manufacture and the last two numbers will be the week of manufacture. So if the number on your speaker is 220947 it will read as follows; 220 is the Jensen manufacture code, 9 will be the year and 47 is the 47th week of the year. The problem is the number 9 does not determine which decade (i.e. 1959, 1969). To determine the decade the speaker was made try to base it on what year the amp was made that it is mounted in. If it is a raw speaker then you have to make an educated guess.
Here is a chart with original Jensen speaker specifications. Click to enlarge.