I tried out a plugin called Maxxbass from Waves that I like.  Does anyone know if Sonar Platinum has any include plugins that do something similar?
 
Tanks!

MaxxBass rocks ... S-Plat includes a ton of really sweet tools, but I don't think you'll find anything bundled with Sonar that does the same thing as MaxxBass.
 
 

Although not using the same technique, I think the closest dedicated plugin included in SONAR is probably Bark of Dog:
https://www.cakewalk.com/Documentation?product=SONAR&language=3&help=ProChannel.13.html
 

You can possibly do something similar using a Send or Aux Send, Tube distortion on the receiving track and some surgical EQ to sharply boost multiples of the original frequency you wish to fatten up. Ill have to give this some monkeying around with, but could possibly do something like what MaxxBass does. Otherwise, catch it on-sale!!
 

The Renaissance Bundle goes on sale often, it has Renaissance Bass which is kinda similar, as well as the invaluable Renaissance Vox, Renaissance Axx, Renaissance Comp and the sometimes useful Renaissance EQ, DeEsser and Verb. Unless I'm mistaken itt also comes with IR-L with its 5GB library of impulse responses. I'm a fan.

I got it in a crazy cheap Gold bundle deal last year.  Gold was like $163US or something like that

It would be difficult to emulate MaxxBass or RenBass.  It actually looks at to lowest frequencies of the audio and boost the harmonics of these frequencies while decreasing the fundamental frequency.  It will change its boosted/enhancing dependent on the pitch of the program material.  This makes the bass sound louder/fuller without having too much low end boost.  This process keeps from eating up mastering volume space.  Bass can take up a bunch!!
 
Gold is a great buy on sale!

MArwood
It would be difficult to emulate MaxxBass or RenBass.  It actually looks at to lowest frequencies of the audio and boost the harmonics of these frequencies while decreasing the fundamental frequency.  It will change its boosted/enhancing dependent on the pitch of the program material.  This makes the bass sound louder/fuller without having too much low end boost.  This process keeps from eating up mastering volume space.  Bass can take up a bunch!!
 
Gold is a great buy on sale!

What he said - well said!    Every once in a while, 'either' single plugin goes on sale.  I think I got Max for 49, and Ren for 39 a while back.  I can't afford a ton, so I save a bit at a time then pick up what I need. 
 
There are some pretty cool things you can do with both - and its not just to bass guitars.   I had an unruly bass drum last week.  DEEP and LOW,  it resonated into the next song (or whole note anyway).   I squashed the bass drum front mic track fast and fairly hard with a sonitus  compressor (love these plugins), then added MaxxBass to reduce the fundamental, and add a bit to the upper bass register.  What was a so so BAWOOOOOM sound, ended up punchy, percussive and full thwackboom sound.   My favorite bass drum sound this week!  
 
LL 
 
   

Thanks ! 
Lots of good info in the above posts
Kbrodog

I've made no secret of the fact that I don't like Waves, and am fond of saying there are plenty of suitable alternatives. I have to admit, however, to one exception to that claim: Renaissance Bass and MaxxBass (two versions of the same plugin, with RenBass offering a bit more control).
 
These utilize a patented algorithm that's also rented out to boombox manufacturers to provide an illusion of more bass. While there are plenty of distortion effects around that can come close, to the best of my knowledge nothing exactly duplicates what these plugins do for bass and kick. RenBass is the only Waves plugin still on my first-string roster.