technical MP3 VBR setting min quality encoding options

[usenfixit]

Hello,

 

I wish to convert wav files to MP3 in the most "lossless" encoding, but I wonder about setting the mimimal bit rate

 

Therefore I put in the encoder options

Encoding mode : joint

CBR: checked

VBR

Quality : 0(highest)

max. bit rate : 320 Kbps

 

Now, the mimimal bit rate can be set as low as 32Kbps or as high as on wish.

 

After some test with the same input wav file, I wonder about the true loss of setting the min bit rate to a low number such as 32 Kbps or a high one as 224Kpbs in the terms of true hearable quality difference. Indeed, if there is a moment of near silence, when setting a min to 32Kbps or 224Kbps, files size will differ significantly, but not the experience.

So my question is what does Switch Sound File Converter really do ?

Is it really important to set a high min bit rate ???

Could a developper explain what

 

Thanks.

 

Phil