when converting wave files to MP3 files, my encoder gives me the option to select bit rate modes, variable bit rate or constant bit rate modes , variable is preset at a bit rate 192 with a quality of 5 and unable to change while constant bit rate can be changed from 16 to 320 ... what settings are usually used and does the use of the MP3 determine the settings ? most of the time, I will be uploading my songs to say sound cloud or reverbnation and can you hear a difference in the audio from one to the other ...
 
I appreciate any information on this ...

VBR lets you create smaller files, and most of the time you won't hear any difference.
 
MP3 data is created in short chunks. VBR lets the encoder determine the lowest acceptable bitrate for each of those chunks independently. Any portions of the song that don't require a high bit rate can then be encoded at a lower rate to save disk space.
 
Typically, a VBR MP3 of music at the highest quality level will have an average bit rate comparable to between 192kb/s and 224kb/s. IOW, perfectly acceptable quality for most things.

Thanks Bit ... Don't know a lot  about all the technical details involved in this ... but thanks to all of you guys, I'm learning .. I hear a difference in the audio between wave and MP3 but not much between different MP3 settings ... didn't know  what was the popular setting for encoding MP3's and why....
 
I like your music by the way .... sounds good ..
 
 

Obsessing over encoder quality settings falls under the "re-arranging deck chairs on the Titanic" category. Here's a blind ABX test that demonstrates the point. Use whatever settings get you the necessary file size. If file size is not a concern, just set it to 320kb/s CBR and forget about it.

I have been using 160 on Sound Cloud as someone posted that they will change your sample rate to this anyhow,, or was that sound click? Anyhow, seems to work without artifacts.