First things first: you're going to hear this a lot from me as we discuss how to get great drum sounds, but don't underestimate how much processing a natural drum or cymbal sound goes through to come out of your speakers or headphones. You might think of it as raw metal ore going through the processes to become a car. That being said, you must start with great "raw" sounds to get great results.
The kick drum is the heart of your kit - and your sound. If you have a great kick sound, you're well on your way to sounding great and feeling comfortable.
There's quite a lot we could talk about regarding the dimensions and material of the shell, and how many lugs and other attachments it has, but that's a discussion for another time. For now we'll focus on two basic differentiators in heads, number of plies, and finish of the head - oh, and muffling, for good measure.
How many plies?
A ply is a single layer of plastic - usually mylar. There are different thicknesses of plies, usually a thin and medium. If you want a really thick head, you're usually going to get two plies. In addition, you can get a single ply head with an extra ring around the edge, so you end up with two plies around the edges to dampen some overtones, but a single ply in the middle. In addition, there are numerous additions to heads like pinstripes, but we'll talk about that in a second.
So what's the difference in sound? For kick drum, you probably have different sound goals depending on what you play. A two-ply head will give you a shorter sustain, darker tone and more "punch." A single-ply gives you longer sustain, brighter sound and more tone.
Here are a couple of generalizations: Single ply is for jazz and recording. Double ply is for rock and live sound. Good luck with that.
Coated or clear?
Essentially, the more you add to a head, the less overtones you get, the less resonance you get, etc. So what gets added to a head (besides plies)? First is a coating. Coated heads provide a warmer tone, less crisp attack, and the texture makes brush playing possible on snare and tom heads. I guess you can play brushes on the kick, too!
Aside from coating, all manner of strips, stripes, dots and etchings have been tried to create a certain tone, response or playability. Luckily, you' don't have to try absolutely every head to figure it out. Most of the head manufacturers have a chart that will guide you to the kind of head you should try based on the sound you're looking for.
I also recommend some sort of patch for the kick head right where the beater contacts it. No matter how softly you play, you'll want to reinforce that spot so that the head lasts longer. The effect on tone can be an issue, but you can usually get what you want with tuning and choosing the right beater.
Alright, this is getting long. More on heads next week! Let's continue the discussion in the comments below.