Maybe someone can help.
I have a 28 track mix that sounds incredible when I play it direct from Sonar X3.
As soon as I export to a wav....it sounds terrible.   Nothing like "what I hear".
So to narrow down the problem I exported only a Synth Drum track and the Bass track.
Again, in the program sounds awesome.
 
When I export there are 2 problems I can hear.   One, is its very quiet....and when I raise the volume to hear it, the Bass overpowers the drums.  
If there was a way to attach the mp3 for you to hear, I would.
 
Any suggestions would be helpful

make sure there are no sends to other outputs on your sound card. They will all be added to your mix.
also, check the faders of your cards outputs and make sure they and on zero.
that is all I can say now based on the details you posted.

You can upload the MP3 to soundclick or soundcloud and post the link here. We can then hear it.
 
Hearing it is the best way to determine what you may be doing wrong.
 
First though, check all your routing assignments. The mix should sound exactly like what you hear. The low volume is a minor issue but the sound is what you need to work on and solve first.
 

Not really, if you hear your main outs 1-2 and you're sending 3-4 for your talent, when you export, sonar will add the 1-2 and 3-4 to your exported file. 
 

Guitarhacker
The mix should sound exactly like what you hear. 

I am using a laptop with an internal soundcard and a Roland Quadcapture interface with everything on the default settings.

Everything is being sent to 1-2.  Nothing to 3-4

check the console if your sound cards output meters are at zero…(after the bus meters)

Yes they are

Here is a link to the mp3
https://soundcloud.com/ba..weinberg/drum-bass-test

I also need to clarify, when I listen on my computer its mostly the overall volume issue.  The overpowering bass occurs when I move to a cd and listen on my home or car stereo, as well as the volume issue.