Ok, I'm feeling pretty good about getting my tracks so they don't step on each other. 
IOW minimal frequency masking, some ducking and aggressive slip editing so no more than a few tracks are playing at any one time means I now hear all tracks distinctly.
I tend not to use reverb and only some subtle delay on the odd track (vox, lead guitar).
The problem is they now sound too distinct. Disconnected in fact. 
Interestingly, it's obvious on my Bose/Harmon Kardon stereo but not so much on my KRK 6's/10"
I need some advice in making them blend again without losing the distinction.
I sure you know what I mean.
I'm assuming it's done in the various busses and master?

X1d Pro Exp

Mike Senior (Mixing Secrets for the Home Studio) advocates the use of a specialised verb for blending purposes.

Very short, no tail (ER's only) and quite a bit rolled off the Hi & Lo ends, then add it a send to every track you think could benefit and adjust send level to taste.

If you run the bus solo, you can hear the contribution each track makes as you fade it's send level up from -INF

That is a good problem to have.

From your description I'd probably put a reverb on the vox - I usually do.  It fills in the cracks between your sounds but subtlely.  Turn it up until you hear it plainly, then back off.  When the vocals stop and the reverb dies, your music should ring out nicely.  If you have a break for lead guitar, put some similar reverb on it to fill in the cracks and see if that doesn't work.

It is easy to get heavy handed w/ reverb.  Once you learn to control your instints, you can use it as a patina tool.

@

Good bus compression can really help glue the track together.  

+1 to Bristol_Jonesey.  Mike senior's book is well worth the read in general.
 
I also use the PC4K bus compressor on the master bus, but very subtly.  I adjust the input so that the needle peaks between 2 and 4dB, and then adjust the output so that it's at the same perceived level as the uncompressed signal.  We're not using the compressor to increase the level, it's just a subtle glue.
 
Then a little light EQ on the master bus too.

"Gluing" really means filling in the gaps, e.g. bringing up bass guitar tails so they bridge individual notes better. That can be done with reverb, but it's a meat-axe approach that can get away from you very easily. It's best used with sparse arrangements. 

For dense rock mixes (which may not require gluing at all), bus compression is a finer tool. Low ratios (1.5 to 2), slow to medium attacks (5-20ms), low thresholds and 1 or 2 db makeup gain. Bass-heavy genres may need a multi-band compressor.

Lots of folks rave about various "bus compressors" such as the various SSL emulations, but honestly I don't know what makes a compressor a "bus" compressor. Seems to me any versatile compressor can fill the bill. I use the same one (FabFilter Pro-C) that I use for vocal and bass leveling, de-essing, and peak control.

M_Glenn_M


Ok, I'm feeling pretty good about getting my tracks so they don't step on each other. 
IOW minimal frequency masking, some ducking and aggressive slip editing so no more than a few tracks are playing at any one time means I now hear all tracks distinctly.
I tend not to use reverb and only some subtle delay on the odd track (vox, lead guitar).
The problem is they now sound too distinct. Disconnected in fact. 
Interestingly, it's obvious on my Bose/Harmon Kardon stereo but not so much on my KRK 6's/10"
I need some advice in making them blend again without losing the distinction.
I sure you know what I mean.
I'm assuming it's done in the various busses and master?

X1d Pro Exp

I also think this is a good problem to have. Instead of reverb, I'd suggest impulses. The reason being, they are much more realistic than digital verbs. When things are too distinct, you have one of 2 little bumps in the road.
 
1. Direct recorded instruments: When you don't mic instruments and go direct on several things, you get "direct". A little room ambience can go a long way. The problem is, most people do not know what to do here and abuse it. Small rooms using what we call "transparent" effects will be the key here. "Transparent" means, clean, clear, not artifacts from the effect that degrade the sound. It's lush, realistic, and believable. Jonesey's tips about Mike Senior are good also. Keep it all in mind.
 
2. Panning: The number 1 issue for "disconnection" is excessive pans that are too wide. The wider you make something, the more disconnected it becomes. It will always be a matter of opinion, but wide mixes sound terrible to me. I don't care who mixes them or how many awards they have. Nothing sounds worse than a drum kit that is all over the mix with toms and cymbals that pan onto the guitar tracks that are panned outwards.
 
Set your pans up like you would watch a show. Draw a stage or better yet, search the net for "stage map" and you will find online free programs that allow you to create your stage and place your instruments on that stage. From there, approximate what the pans on those instruments would be by having 100 all the way to the left of the stage, and 100 all the way to right of the stage with 0 in the middle. Now try panning your mix and see how much tighter it sounds.
 
Watch for stereo imagers and effects that have "widening" like Sonitus reverbs etc. Anything over 100 in the width area is beyond the stereo pan field of 100L/R. Too many stereo effects that are not width controlled will disconnect instruments as well depending on how much effect is used. Always control how wide your stereo effects go. By default, they are set to 100L/R. Use a Sonitus Phase to control how wide they spread if need be by just using the width control to tighten things up.
 
Also, a gentle low pass on your entire mix can also sort of "glue" things together and snap out some of the cleanliness that may be making your mix sound a little too pristine in the high end so to speak. Try not to do that unless you have to though. The last thing you want is that great mix you've done to be too dark and sort of lifeless.
 
Personally, though everyone is entitled to their own opinions, I'd stay away from any sort of bus glue or compression on the master bus. The reason being, not many digital plug compressors (in my opinion) do this the right way. Prime example....
 
"Ok, so my question is, I'm using a compressor on my master bus. How do I know when enough is enough Danny?"
 
Answer: Well, you shouldn't really hear it...if you hear it you're using too much. "Yeah, but Danny, why should I use it if I don't really hear it?" Exactly...and now you have your answer. :) Do this with a hardware compressor to where you mix INTO it, and it's an entirely different ballgame. :) You hear "color" as well as actual glue taking place where the entire mix is sort of patched together as an entity. You don't get color out of plug compressors unless you use a UAD Fatso in my opinion. That is the only compressor I mix into. You literally put it on your master bus and THEN mix your song. You don't put it on after.
 
Don't get me wrong, you could use a compressor lightly like the advice you've been given, but to me, that will NOT glue a mix that is "disconnected".
 
Anyway, those are the things I would think about. Try anything and everything if you must...but the above will definitely get you results. :) Good luck!
 
-Danny

I'm one of those beginners who was drawn in by the concept of "magic mix glue" compressing through reading tutorials and watching videos etc, so I ended up slapping it on the master bus of everything I'm working on, very gentle settings etc, forgot about it, then took it for granted. Then recently, it occurred to me that I didn't really know what in the hell it was doing, or if what it was doing was better or worse (I really couldn't tell), so I stopped using it. 

Because what I do is almost all soft synths, I figure I can control the dynamics on a fine level through velocities, synth settings, volume automation etc. Although I can see how master bus compression could be more beneficial in the case of recordings of real instruments. On the whole though, I'm leaning toward less compression on individual tracks as well. 

This all seems like excellent advice and has given me lots to try.
I have been assuming compression would factor in and have been using it in 4 db increments in a series. (On the original recording, the track before EQ, the buss and the master) this certainly brings up the levels but I wonder if it is actually contributing to the separation?
The extreme panning I am also guilty of and backing off a bit makes good sense in my case.
As said, I have tended to avoid reverb lately due to the tendancy of pushing the sound back where I have worked hard to get an up close and personal sound. (Singer/songwriter style)
But this does make sense too, done subtly of course, and thanks for the suggestions of settings.
Would any of the stock reverbs be good enough or have I arrived at the point where I should consider an outside purchase?

Since we're talking about Cakewalk, I put a piece with 15 very distinct tracks all on the Neve emulator in Pro Channel, and it accomplished a subtle gluing effect--perhaps some similarity of coloration that they have in common now. I doubt this would fix a mix with more than subtle 'gluing' needs, but I'm happy with what it does for mine.