Any MP3 encoder should be capable of 320 kb/s CBR. It's just a matter of figuring out how to set it up. LAME is free, works well, and can be set up to work directly from your SONAR projects.

Guitarhacker
Always try to work with waves up until that final conversion to MP3... then choose 320kbs as the conversion rate.
 
The file sizes you mentioned are way out of line for what you are talking about.  Something there doesn't quite seem right.
 
Sonar exports wave.... you convert the wave to MP3.... if you import it to sonar again and "boost the levels" and then export it (as another wave) and then convert that, you have done some serious degrading of the bit rates through those conversions.  It will sound bad.
 
So go back to the original project in Sonar, and export it as a wave. If the levels are low, use something like a wave editor to normalize the WAVE to 94% or there about and THEN you convert to MP3.  With a decent output level from Sonar, if you have done your work correctly, the amount of boost needed should be slim to none. This is the process I use.
 
Audacity and WavePad are good (and free) wave editors that do the job nicely.
 
A closer read of the OP does not say you created the MP3 from a Sonar project.... so if this is the case.... simply import or open this file in WavePad or Audacity as MP3.... use the normalize function and play it back to listen. This should boost the level and introduce no bit reduction. The music should still sound as good as the original MP3, but just a bit louder. Click the SAVE AS button and save it as the SAME bit rate as the original or higher.
 
 

Thanks Guitarhacker,
Yes, you got it on the second look at the OP.
The original mp3 is a music mix downloaded from an audio website, i didnt create it, just trying to boost the level of it. It plays back at about -6db. It has a picture attached to it, and apparently Sonar won't import it as such. Does Audacity care if it has a picture?
 
Thanks again also Bit.

Thanks for the links scook.

FWIW, Waveshop will import audio files with embedded graphics. Does normalize. Does 320b/s with the extra lib. Is 64bit, works inside SONAR too. Quick and free.

I use WAVEPAD.... NCH makes it and it's free.   Always check the sample rate of the original MP3. Saving higher is OK but don't save lower if you can avoid it. And WavePad asks you for the rate.... well when you set it, it defaults to that rate until changed.

Another solution to consider http://sourceforge.net/projects/mp3gain/

scook
FWIW, Waveshop will import audio files with embedded graphics. Does normalize. Does 320b/s with the extra lib. Is 64bit, works inside SONAR too. Quick and free.

Hi scook, I installed Waveshop and it's working well, thanks for suggesting it.
 
I just imported an mp3 recording of a jam into Sonar to tweak it a little with some stuff.
How do i open Waveshop in Sonar in order to just export the mp3 when I'm done?
Thanks

I would export the wave file out of SONAR and open the wave in Waveshop to do the conversion. The reason is, usually when working in SONAR, everything is happening non-destructively so if you thrown a clip in an external editor, SONAR passes the raw clip. If you want to launch Waveshop on the track with all of your changes applied, you will need to bounce the track first (just as easy to export). Then open the bounced track in Waveshop.
 
That said, Waveshop can be integrated into SONAR like any editor using these instructions http://www.cakewalk.com/Support/kb/reader.aspx/2007013099 If you wish, copy the lines below into a file with .reg extension, right-click and merge will add the file to your registry. The execPath below uses the default install path for 64bit Waveshop, if installed somewhere else, update the path.
 
[HKEY_LOCAL_MACHINE\SOFTWARE\Cakewalk Music Software\Tools Menu\WaveShop]
"ExePath"="C:\\Program Files\\WaveShop (x64)\\WaveShop.exe"
"MenuText"="&WaveShop"
"StatusBarText"="Run WaveShop"
"Type"="WaveEditor"

HAPPY THANKSGIVING EVERYONE!  :)
 
Thanks scook. The installation path you provided will be very helpful. I wasn't sure where to find it. Thanks for the Cakewalk link. I was assuming to put the Waveshop .dll into one of Sonar's fx folders and rescan. I have some more reading to do...
 
I thought the reason for opening Waveshop in Sonar was to avoid converting the mp3 file into a .wav and then finally back to mp3. Would the only way to accomplish that be by upgrading the Sonar to export mp3? Thanks again.
 
 

Waveshop is an editor with an integrated mp3 encoder, not just an mp3 encoder. If you want an mp3 encoder for SONAR, there is a link further down in the this reply.
 
Depending on what your are doing in SONAR, it might be just as easily accomplished in Waveshop. You initial post was about increasing the volume of the mp3 file. That can be done directly in Waveshop without SONAR. FWIW, all programs that manipulate mp3 files have to convert them before processing because mp3 is a compressed format.
 
In your specific example, the initial problem with SONAR was it's inability to handle mp3 files containing images. That meant the file had to be converted to a wave prior to importing into SONAR. Waveshop does not need the file converted prior to opening, it does the conversion while opening the file.
 
Then comes the volume adjustment, both SONAR and Waveshop have tools to normalize the audio.
 
Next is mp3 export; mp3 files can be created three ways with SONAR:

• The integrated mp3 encoder (a one time fee good forever on all future Cakewalk DAWs).
• An external encoder, here is a post on how to get the latest version of LAME and integrate it into SONAR (the integration steps have not changed since the post). One thing about this method; there is no convenient way to adjust the encoder parameters on the fly. The integrated encoder has a popup dialog, the external process lacks. It is possible to create several predefined export entries to handle most situations though.
• Export a wave and convert after export (what your are doing now).

Waveshop provides an integrated mp3 encoder.