Lately, my sound from my ampeg cabinet has been giving me a horrible rusty distortion sound. I just changed the tubes in my Ampeg SVT 3 pro head, the only one I didn't change was the main one. Which the guy from Sam Ash said if it doesn't change, I will have to change that one. But, I'm now wondering if I blew a speaker in my cab. It's not really a distortion it makes like a growling noise almost evrey I play a note. If I did blow a speaker, I have an Ampeg SVT 4x10 classic cab. You can notice the noise more on lower notes, and the E string. How much do speakers usually cost?

Hmm im afraid i dont really understand your situation, a blown speaker should make more of a rattling sound like something is loose, rarther then a growling noise. You might want to see if something is wrong with the tube, or attach another head to it and see if it works (maybe just borrow from a friend if you dont have another). Speakers arent to much but it all depends on the kind of quality your looking for and if you want the same exact kind that was in the cab originally.
Some people say I might have blown a subwoofer do to it almost like breaking up the noise on deep notes. hm...
No, my bass is not maxed out. Plus, it just started doing it last show my band had. Do you have a feeling it's my subwoofers? Also, does Sam Ash or Guitar Center sell them?