As Shawn says, Boost 11 is the down and dirty way to compress bass. A basic, easy to use visually self explanatory tool (brick wall limiter).  I know you probably don't want to hear someone tell you that a solution to your problem is something you don't currently own, but for a multitude of reasons, one of which is the beautifully executed multiband compression, get Ozone.  I fiddled with the Sonitus compressor for a long time and was never satisfied with it, then, in order to do mastering, I got Ozone, and now I use it everywhere, not just on the master buss.  The compression is simple to dial in, and it sounds fab.  Once you discover the benefits of multiband, you'll never go back.

Poco
Once you discover the benefits of multiband, you'll never go back.

Don't overlook the LP-64 Multiband in SONAR. It really is linear phase.

cowboydan

• Step 2 – Insert a compressor and a phase flipping plug-in on this track (We will call this “track 1″)

Couldn't you just use the 'phase' switch on the track in Sonar ?
 
Great stuff guy's, you can pick up a lot of stuff from reading in these forums, and it's mostly free from all the ego and elitism etc that you can find at other places, another reason why I love using Sonar now days :)

I seem to get best result when starting with the slowest possible attack and fastest possible release, and proceed to slowly shorten the attack, until I start to lose the attack and the sound dulls out a bit. That's where I pull it back a little.
 
Then I do the opposite with attack, work your way to a slower release which times well with the song.
 
That's the default setup I use on all my compressors and it works well for me. But for some people, the opposite (as suggested by Wicked) may be a better option. I guess the idea is to spend time trying all kinds of setting and experiment with it. You won't break anything.
 
On a bass in particular though, I'm still inclined to work with LA-2A models. It just seems to make things a whole lot easier. That being said, there's usually a lot going on on the bass track in my songs - compressor, EQ, Wave's Bass Rider and/or limiter. It's also one of the few places where I sometimes use multi band compression.
 
All that with a grain of salt - these are things which help me improved but I have yet to mix anything as impressive as my favorite records. ;)

LA-2A models are indeed very easy to use and sound amazing, however they don't suit all program material and uses. But for "leveling" they just sound great. 
 
Personally I have a thing for 1176 type compressors right now. They're especially wonderful on guitars and vocals and again, very easy to dial in a great sound. Took me a while to get used to the backward attack and release controls though (in fact I still have to think about it, same way I have to think what high-pass and low-pass mean for a second every time lol). I have the Native Instruments VC-76 and use it a lot. 
 
One thing I've found about compression is that sometimes I can't really hear what's going on unless I turn the volume way down. It must because the ears are more sensitive to dynamic changes at low volumes or something. Try it - next time you can't hear what the compressor's doing, turn the volume down. 

This is a good read:
 
http://forum.cakewalk.com/How-to-set-up-a-compressor-properly-m2116921.aspx
 
Also I posted the original article on using the null method to test compressors:
 
http://forum.cakewalk.com/How-to-test-your-compressor-plugins-Which-one-is-really-best-m2282782.aspx
 
The null approach is interesting. What you are wanting is the sound to smoothly come in and go away when compression takes place. 

and don't be afraid to use hard LIMITERS to do compression work...
 
and the way you would use them there, is where the meters hardly even kiss the signal,
and use your ears....... not the reduction meter, to hear a change.
it is different than typical compression.
 
it 'colors' the sound in a different way than regular (non limiting) compression
 
 
it almost works as a 'compander', and you have to mix INTO it for it to really work well.
 

sharke
One thing I've found about compression is that sometimes I can't really hear what's going on unless I turn the volume way down. It must because the ears are more sensitive to dynamic changes at low volumes or something. Try it - next time you can't hear what the compressor's doing, turn the volume down. 

Just as an FYI, the human ear has a harder time with amplitude discrimination than pitch discrimination; and at high levels, the ear tends to act with a sort of built-in limiter. This is one reason I mix at low levels then do a reality check at higher levels just to make sure it will sound good if people crank the volume up.

One of the things about using limiters for compression is that they are fast and designed to be.  A limiter has a quick attack.  As a result it will always attack the fast transient edge of any mix and start messing with it. Usually in a way I don't like.  Especially when I start comparing the unprocessed (premastered) sound to the processed (mastered) sound at the same volume.  When you start doing this you remove the level change and expose the mix integrity change a lot more.
 
(PSP Xenon allows you to alter the limiter attack time a little more than most and I like the fact you can dial the snap back into a mix again)
 
Compressors on the other hand are more adjustable in the attack region and it is the reason I like setting the Attack part of a compressors first especially with a mix. You need to keep the mix integrity intact all the time while mastering.  Altering the mix attack transients is one sure fire to ruin a mix.  I like the idea of the compressor in the middle of the effects chain grabbing onto the rms part of the sound more and being a little slow in doing it too.
 
I do agree with Bats in relation to not limiting hard and just getting the limiter to tickle the signal.  Xenon sounds its best under those conditions.  With care in the earlier mastering processes it is possible to only ask the limiter to do another 2 or 3 dB of rms level raising at the most.  If you are pushing your limiters for lots of loudness, you are asking too much of the limiter and it is damaging the sound more so.

FYI - Boost11 is one of those plugins not meant to be used during recording, it will add a bunch of latency - so wait until you are ready to move on to mixing before loading it into your project.  (if you already have it there you can power it off until you are ready to mix)
 
Bob Bone