I know it's a lot easier said, than done, but it is possible to train yourself to speak in a low(er) bass voice. I started doing it at about 12-13, and by 14-15 it was my voice. Not sure if it just gradually deepened with puberty or not, but by the time I was 14 everytime I answered the phone EVERYONE thought I was my 16 yr old brother.
I started hormones just about 6 months ago, and the Dr thought I had been on T prior, because of how deep my voice was. It really hasn't gotten any deeper since I started T, and I was told it probably won't. Will power is a bad bitch!