24 bit lossless to mp3 using lame, For best quality, do I normalize it first? Options

[mezzanine]

I want to convert a 24 bit FLAC to v0 mp3. (the source is not vinyl, I'd like to avoid that conversation)
Currently its highest peak is -9dBFS which is pretty quiet. Should I normalize the 24-bit file so that it peaks at the maximum value first?

An alternative way to word this question:
Does lame truncate 24 bits to 16 bits before encoding?

I'm also curious about dithering. Should I dither to 16 bits using a high quality algorithm like SoX and then feed that to lame to encode?

Thanks!

[DVDdoug]

An alternative way to word this question: Does lame truncate 24 bits to 16 bits before encoding?

No.

Currently its highest peak is -9dBFS which is pretty quiet. Should I normalize the 24-bit file so that it peaks at the maximum value first?

If it "feels" too quiet, then yes I'd normalize. Since you are probably going to crank-up the volume during playback, you might as well make it more convenient by "permanently" cranking-up the volume.

I'm also curious about dithering. Should I dither to 16-bits using a high quality algorithm like SoX and then feed that to lame to encode?

In this case, you don't need to downsample.

Whenever you downsample to 16-bits, it's up to you if you want to dither or what algorithm/application you want to use... At 16-bits, the dither is somewhere around -90dB and nobody is going to know if you dithered or not, or if you used a "good" dither algorithm.