People, IT IS ALL IN THE CORRECT TWEAKING OF THE SYNTH!
First of all, write your KBBB line! write the BBB as 1/32 notes but over 1/16 positions. This is made so that the small tail of every bass note (it holds the major part of those lovely fat subfreqs) is not mixed totally with the next note and thus we can hear them 3. if not they mix into each other and its like a continuous subbass-rumble. Try with notes of the 0 octave, like from F0 to B0, later you will adjust them more precisely.
Now the Synths
if you use Cronox2 (I recommend it eagerly, its very fat and crunchy this synth):
First of All, turn off all types of effects on the synth you might have, slide down until 0 all the ADS(F)R both of the filter envelope and the amplitude envelope. At this stage you will not hear anything. now you go to the OSC section. in Cronox there are 2 OSC. Choose the upper one (it has a nice Saw wave), you choose it moving the MIX button, up is OSC1, down is OSC2, and of course you can mix them but for now we dont need this. (notice there are also FM and AM switches, Dont use them for now, Use the MIX)
Now you have to choose the clean SAWthooth wave (the one that looks like a peak and not the triangle

you will notice also a Detune, and Spread buttons. we dont need them for now.
On the filter section choose LP24, also put the buttons TRACK and DEPTH in the middle. Now push play of your DAW. Still nothing, and sure we have both ADSR turned off.. and here starts th real tweaking.. try pushing up a little bit the S (sustain) both of the filter and the amp envelopes, also on the amp envelope push just a lil bit the A (attack) too. WOW there is a SOUND already! and nice fat one! so now you can continue tweaking the DEPTH and the TRACK buttons a little but until you get a bass line you like. also you can try other notes than B0, could be G0 or anything else. Remember, the main tweaking is in the S button but just if the rest is down. you can try also to move a little bit the Release of the Amp Filter. but really A Bit! otherwise you will get continuous and distorted bass. So this is the basics for the Cronox2, once you have made this you can try experimenting with the other parameters but always very slightly or you will ruin everything.
For the VB1
the same for the notes, short notes on the 0-1 octave depending on what do you want to make, melodic or crunchy bass... or maybe both

The trick with the VB is to NOT to use its original GUI, it is very frustrating and also VB1 has a decay and release parameters that are not shown on its original GUI, so you will have to tweak them via Automation or via Standard GUI (live and logic permits this, in Cubase you will have to access them via Automation).
so you will see 6 parameters:
decay, pickup, pick, volume, release, harmonics.
slide them all to the left except the volume of course and leave the release to 100% or 98% for a small tail and thats ALL!!! now you have to search for the best note and you will need some good eq to shape it.
other verrryyyyy nice one is the tritium but again, use it carefully!! it can sound horrible or it can sound great.
trylogy is also DA MONSTER but i assure you, dont use the presets!!! you have to build the bass from scratch, but what is great about trylogy is that it has recorded the best SAW WAVES out there from the most legendary analog synths, juno, moog, etc.. so we build the bass in trylogy the same way as in cronox! but using some of the saw-waves from it.
NOW THE EQ, DISTORTION and COMPRESSION.
once we have achieved a good bass without any other help but the synth himself we can shape it furthermore. a lot people use rbass, or a bass maximazers etc.. dont use them...! you can achieve great subs from the synths themselves and from a good EQ. Here is a Major Trick! For transparent sculpting use EQs that proof to be good analog emulators of old vintage EQs. this is because they treat the bass much more smothly, but with more definition and contrast. I can recommend the Stillwell EQS, 1973 and the vibeEq. but of course to use them you will need a little bit of understanding.. most of them have HPs, LS, MIDs, HSs,
HP - highpass, LS - lowshelf, HS - HighShelf.. just learn there particular functoins (look in google) and than go back to sculpt your bass. with an eq of this kind you dont need no rbas, subbas, mega-doomic-subbasic-madness or whatever other vst that claims this...
for compression and sidechaining use the TC - Native bundle. its so easy and so transparent. a lot people use izotope trash and me also have recommended it, but it is used to boost a weak bass, if your bass is fat from the beginning no use of it is needed. another very good dist effect, very simple, but very clean and contrast giving is the Oligarc-Drive


i hope i have helped somebody out there.
hugs to all FREAKY=TWEAKERS and chek my psyport profile for some tunes

http://www.psyport.net/profile/Oxidelic