I use the free Lame encoder because I render my projects as .wav files and use Ozone 7 standalone for mastering. The program is available in both source code and in binary form, and it's actually the core for most MP3 encoders on the market today, including, I believe, Sonar's. It's really easy as pie to use, assuming the pie you like uses cryptic commands and requires downloading zip files from an obscure web site.
You can get the source code and lots of information about it at:
http://lame.sourceforge.net/ But if you're like me you don't want the source code, you want a ready to run program. You can download a binary at:
http://www.rarewares.org/mp3-lame-bundle.php Note that they have a 64bit version on that site, and that's what I use. The latest version is 3.99 and the name of the version I download on that page is
LAME 3.99.5 64bit Once you've downloaded the zip file, extract everything and put it in an easy to remember location, like
c:\lame or
c:\program files\lame. Then you can add the location to your path, or type in the full path every time, or better yet, put it in a batch file. Here's the content of a simple batch file I use. Copy it from this post and stick it in a text file with a .bat or .cmd extension. For example, assuming you name the batch file "runlame.cmd":
runlame "My input wav file" will result in a file labled, "My input wav file.mp3"
Here's the batch file:
"c:\program files\lame\lame.exe" -b320 --ta "Artist Name" --tl "The album name" --tt %1 --ty "2016" --tg "Rock" --ti "A250x250pixeImageToEmbed.jpg" %1.wav %1.mp3
Those extra parameters specify things like artist, title, year created and even a photo to embed in your mp3 that mp3 players will display while your awesome song is playing.
--tt %1 The command uses the first argument on the command line (which is the name of the wave file without the .wav) as the Title MP3 tag. If you want to change that, change the --tt parameter to something else.
-b320 tells lame to encode at 320kbps. You can change this to any one of several supported bit rates.
--tg identifies the genre, which is selected from a known list of genres. To find out more, google mp3 genre to get a list, or check the lame help document in the folder where you dumped everything, index.html.
--ti is a path to an image file to embed. There's rules about sizes images, check the help docs. It's easy for me to remember 250x250, which is what I use.
When you're checking out the help docs, one thing to keep in mind is, generally speaking, if you don't understand what the heck they're talking about, you probably don't need it.
You can also add lame as an external tool to have Sonar run it at export time. Use the external tool configuration dialog to enter this command line:
"lame -b320 %I %O"
Check out the help docs on the external configuration tool, and check out the Lame help docs too. It's quite powerful and very flexible.
One other thing; if you want to put more stuff in your mp3 file ID tags than lame supports, there's a great freeware tool called Mp3tag, which is a great tool. The version I'm using of that little baby is 2.78.
Good luck!