Once you get the head on the bass drum, it's time to get it sounding good. If you play it as soon as you get the head on, it isn't going to have a great sound. As with the other drums, lets start with the resonate head. In this case, that is the front of the drum. Lay the drum down, front side up. Whenever I tune a drum, I like to muffle the opposite side so it doesn't interfere with what I am hearing as I tune. In order to do this, I just slip a simple pillow under the drum.
I start tuning by loosening all of the tension rods and then retighten each of them to a barely snug feel. This insures that all of the tension rods are relatively evenly tightened. Now I use my finger to tap the drum a few inches from each of the tension rods. As I do, I listen to see which of the tension points are higher and which are lower. The more you do this, the more your ear will develop and you will be able to better hear the differences. The key is to pick which of the tones you like best and adjust the other tension rods to match that tone. Once I get the head tuned where I want it, I turn it over and start on the batter side.
The steps for tuning the batter head are almost exactly the same as the steps for tuning the resonate head. The difference is that you also want to pay attention to how the drum feels when you play it. As you gain experience as a drummer, you'll develop your own ideas as to how a drum should feel. I like a somewhat tighter feel to the drum, so for my first pass I tune all of the rods to the higher pitched tones. Once I've got the drum adjusted where I'm happy with it, the next step is to attach the pedal and see how it sounds in actual use.
With the pedal attached it's time to adjust the muffling that I use. About a year ago, I started using a piece of foam along the inside bottom of the drum. I allow the foam to lightly touch both heads. After adjusting the foam, I find that still don't like the sound. The next step, for me, in muffling is to place a towel that I've folded up and duct taped together against the batter head. To my ear, that really sounds a lot better, but still needs just a little work. To finish things off, I use a muffling ring. There are many varieties of muffling out there. Each one is going to affect your sound in different ways. You really need to experiment and find what gives you the best sound for your ear and your style of music.
We also have an entire section based on tuning your drums, and achieving that perfect sound that you are going for, or click here to learn how to tune your snare drum.