stock CD player has extra port?

[Blacdout96]

Well I just bought a stock factory CD player from a friends of mine. It came out of his 95 Z28, and is a bose series, just like what I have in my car, now I go to look at the back of both and for some reason it has an extra port just to the south of the main plug in on the right. Now Im wondering what it is, is it for A 6 disc CD changer or something? Like I said, we both have Bose so its not for that, and my car is a 96, so we have that funky faceplate look for our cars. does anybody know what its there for?

[Blacdout96]

Update: I installed it, itturns on, works, but theres is no bass!!! I hope that extra port isnt for it. now i definantly need some help wiht this, im not too keen on incar stereo systems. and yes i did turn the bass up, adn there really wasent anyhting.

[Blacdout96]

Another update: its not accepting CD's, neither regular CD's or CD-R's, Im gettign so fed up. anyone got a clue?

[Tru2Chevy]

Try posting up a picture of the back of your old one and new one.

Another update: its not accepting CD's, neither regular CD's or CD-R's, Im gettign so fed up. anyone got a clue?

Is it not pulling them into the unit, or just not playing them?

- Justin