Hello, I too am a newbie that has recently started a vinyl digitizing project. Things are going well except for one problem. When I convert from wav files to mp3, the resulting mp3 file sounds about half as loud as the wav file. I am using Audacity to stereo record as 32 bit float files at 44.1khz, no editing except for splitting tracks, exporting as 16 bit wav/pcm files, normalizing those files using "Normalizer10" for archiving onto disk and then opening those files (either from disk or the hard drive) using Audacity to export as mp3's using LAME v.389 encoding at a bit rate of 128kbps. I'm very happy with any version of the .wav files but the created .mp3's just don't sound quite "there". Do I need to use an mp3 normalizer on those? Oh yeah, the sound card is a Sound Blaster Audigy something or other, but I think the problem is farther on down the process. Again, I'm a rank amatuer just learning about this stuff and I may be using some incorrect terminology, but I was hoping someone out there might have some experience/ideas/suggestions with what may be going in this scenario. Thanks in advance for any help.

How do the WAV files sound after you've normailzed them, the same volume as before or quieter?

If they are quieter check to see if this "Normalizer10" that you mentioned ( is it a plug-in? ) has any volume settings ( dB ). If it has and it's set at arround -90dB change it to -97dB and see if that is any better.

Well for one thing 128kbps mp3's just don't sound very good or 'there' anyway. Do you have some reason for such a low bitrate?

If you burn your newly created WAV's as an audio CD how do they sound?

I would not normalize the WAV's. I would take the WAV's and use CDex (free),no normalization, to convert to mp3 using LAME set to '-alt -preset standard'. I would then finish up the mp3's in MP3Gain (free) set at about 92db. MP3Gain will normalize and also eliminate any clipping. Although the file will be larger than your 128kbps mp3's the end result should sound identical (to these old ears at least) to your original WAV.

Thanks for the quick responses. To answer MJB first, the wav files sound the same, normalized or not. I don't believe "Norm10" is a plug-in, and it has no volume setting that I can tell - just a percentage setting which I believe is to set just how much change you can allow for. How's that for saying "I don't know"?
Thanks also MysticEyes. I thought 128kbps was a normal bit rate for mp3's. File size is not a problem so if I continue to use the same method, I should jump up to 256 or more? I did try one conversion at 256k and I don't think I could tell the difference, but it was still different than the .wav file-I can guarantee that I am not blessed with great ears so I am surprised I can hear a difference that would matter to me anyway. So far my focus has been getting the vinyl digitized and have been archiving the wav files as data rather than burning as audio. Sounds like I better investigate that step too. I thought normalizing the .wav files was important to keep levels uniform between different sources of music? In the meantime I shall take a step back from my approach and try the process you suggested using CDex and MP3Gain. Thanks once again for the replies and suggestions; I'll let you know if it makes a difference.

Taken from our MP3 FAQs, this gives you some idea of bitrate values:

16kbps - Telephone
24kbps - Shortwave Radio
32kbps - AM Radio
64kbps - Voice
96kbps - FM Radio
128kbps - Tape Cassette
160kbps - Hi-Fi
192kbps - CD
256kbps - Studio

128kbps is great for portable MP3 players as the files are smaller so you'll get more on the memory. Personally I tend to use 192kbps but only for playing at home on the PC. Our "audiophiliacs" on here who like to cut, splice and edit will probably recommend no less than 256kbps.

I'd strongly recommend my iPod standard rips - EAC Lame VBR with ubernet.org [sorry Boss] settings. This gives you an average bitrate of 198 which is the lowest rate that still gives good sound quality but also gives a compact file [around 50/60MB per album].

The Lame -alt -preset -standard, VBR (bitrate varies from 128 to 320 when needed), joint stereo plus various tweaks, will always sound better than 256kbps CBR, while providing a smaller file size.

The Ubernet boys advise against normalization. Why have all your music at different levels? MP3Gain not only gets all your audio to the same level, a good thing, it also eliminates the clipping which always seems to be present in far too many mp3's regardless of how they were procured/encoded.

"Our "audiophiliacs" on here who like to cut, splice and edit will probably recommend no less than 256kbp"

Na! m8 we're goin@ 24/96 and hopefully in the near future 24/192 - mp3s're fer wimpz