Kicks are a bitch.

My only words of vague wisdom on this are that some samples are inherently crap. No amount of polishing will help them, however much you like the attack if the tails crap it's gonna be a real pain the arse.

I've got about 600 kick drums on the computer here because I spent the best part of a year looking for the right ones, and of the 600 there's only about 6 that I'd ever really use.

There's a lot of layering of drums goes on but you have to be quite careful not to introduce a bit of weirdness and phasing that you don't want that creates an ugly hole in the kick as it plays.

f you are layering kick drums on top of each other then timing differences can make the sound completely different - if you are triggering from a sampler layered kicks will sound different every time - this will suck for repetative fast beats so either record loads of different ones and pick the one you like or record the layers separately and sort them out on some audio tracks where there won't be any timing issues

That said there's lots of tracks out there that sound good with really quite dubious kicks.

Also, thinking about it ...

Worth zooming right in in a wave editor and looking at the waveforms and trying to decide ifyou can see and edit out any wierd bits or quiet bits. you can do a lot more with a wave editor on this front thatyou can fix with plugins.

Don't overdo the compression on them you can make a dramatic difference to a kick with ratios less than 4:1.

ou probably don't need the gain reduction meters to be reading much more than 6-8db of cut or so normally otherwise the attack of the sound will be way in your face. (at 6db of reduction the attack will start about twice as loud as the rest of the kick sound ...)

make sure your compressor release time is set such that the compressor returns to 0db gain reduction in between each kick otherwise your first kick drum will sound different from all the others ...

Don't boost stuff with an EQ unless you really have to. Usually kicks need a bit of a cut in the mid if they aren't sitting.

Sometimes they have a really hard top end that makes the mix sound small and cluttered and a 6db cut using high shelving eq makes a massive difference to the mix.

Sometimes they have a shit load of sub bass that doesn't help at all, use a hi-pass filter to sort this out (about 30-50Hz probably). You can sometimes hear this in headphones but probably won't be able to tell the difference on monitors unless you've got gods own monitoring system. it'll sound far less muddy on a rig if you get rid of any excess sub bass.

if you're really struggling to fine tune a sound then maxbass from waves can help. it make a very full and middy sound if you want that ... often a bit too much, more usefully you can also add the bottom octave with it (use the dies bassum preset for a starter) ... use maxbass with care.

EQ, Maxbass and filter before the compressor normally. if it sounds good the other way then go for it, but generally best EQ and Filters then Compression.

Once you have the perfect sound, bounce it down and load it back into your track this time with no effects.

Zoom right in again check two things:

Firstly that the wave forms first big peak goes upwards, this will sound subtley more upfront (assuming your speakers and cables are wired right) as the cone comes towards your face first creating a pressure wave as opposed to sucking the air away from your ears which does sound different.

Secondly zoom right in again and check that it actually starts on the beat and that none of the processing (or the original sample) has left a gap at the beginning. Kicks sound better when they are dead in time. It's much more difficult to guarantee this if you're triggering them from a sampler so I always run the important percussion from audio tracks.

All this stuff applies equally to bass, especially the cutting unwanted sub stuff which can often mess up a bass track badly.

if you've got a lot of bass activity in your track you can use a shorter kick drum sample (just zoom in and chop the thing and then fade the last few cycles of it), if you've got an emptier or middy bass part then having a longer deep tail to the kick can be useful.

But above all start with a half decent sample that has the right kind of attack, harmonics and tail.

That's what I do anyway but i like a really clean tight sound, you might need to do something different if you're doing nastier hard stuff..

That's quite a long list of stuff (i was only going to say don't use a crap sample to start with) ... hope it makes sense.