How one would determine polarity of Altec 808-8G ?

WARNING!!!DON'T DO THIS!!!!!(What was recommended by Joe A.) I'm sure he meant well, but isn't familiar with the Altecs. I have put low voltages through an Altec 802-8g, on the order of .5 volt and used a magnifier to observe displacement, and the terminal markings are correct - the red is indeed positive. Looking from the back of the driver this would be the left bottom push terminal. Hooked up accordingly, this would give the dome a positive displacement down the throat of the driver, out into the horn.

I was told to use a 1.5V battery, NOT a 9V battery for testing a speaker's "polarity" (phase).

Apparently this Altec speaker (I am not familiar with) is very sensitive to applied DC voltage so proceed cautionsly.

A safe approach involves use an ohmmeter set on the low [R X 1] scale, which was a nominal 1.5 vdc output. The output impedance of the meter helps reduce the applied voltage/current surge to the voicecoil. A 1.5V battery with a flashlight bulb connected in series should also be a safe current limiter if you have no meter, but do buy a at least an inexpensive DVM which is pretty much mandatory for speaker work anyway. Limit the time duration of the applied dc source voltage to only as short a time as necessary.
The aforementioned regarding polarity behavior is accurate.

Thanks for your inputs. I used 3 volts and observed the diaphragm moved forward. It easier to see diaphragm movements if you let the light shinning on the diaphragm at certain angle. I also noted that the metal nut/cap that clamping the speaker cable onto the speaker had an dash stamped on top. It looked like a negative polarity sign but it was on the positive speaker tap.

"I also noted that the metal nut/cap that clamping the speaker cable onto the speaker had an dash stamped on top."
After looking at different Altec HF drivers. I found that the dash was actually a number 1 and the other cap had a number 2 stamped on it. I gathered that number 1 is positive and number 2 is negative.