How do YOU create long and sustained kicks?

How do you guys personally create those long and sustained kicks, to be exact, tracks with no noticeable bassline, only what seems to be kick mud and rumble in the whole 1/4 bar. Those drumcode kind of kicks (can't find any examples right now for some reason lol, but I'm sure you guys know what I mean).

EDIT: For the past day I have fiddled around with "stuff" and I have come to a clear conclusion. Convolution reverb is the way to go here. It has much more character and every space sounds different unlike conventional artificial reverb. Really has that warehouse kind of sound. Pair that with some distortion on the kick (D16 Devastor 2 works wonders for this), and you got a really great effect. Everything else I've tried sounded sub par compared to this technique.