I have been using several different programs to rip CD's this past week (EAC, CDex, dBpoweramp & Audiograbber) to see which one I preferred. One thing that did not vary was that I used LAME 3.97 final on all of them. I had been using WMP 11 as my main library to listen to and sync. I decided to try Media Monkey, which is quite similar, but uses less resources. When I imported the files to MM, I noticed that the bitrate showed was vastly different from what was displayed on WMP. An example is Coltrane's "A Love Supreme" ripped using dBpoweramp - track #1 on WMP: 192/kbps, on MM: 145 - track #2 on WMP: 160/kbps, on MM: 151, track#3 on WMP: 192/kbps, on MM: 148. Except for track #2 those differences are rather alarming, but not as much as the results from the next disc (Soul Trane by Coltrane). ON that one, WMP showed 160, 128, 128, 128, 160. MM showed 83, 81, 83, 80, 82. These were ripped using EAC. How is this possible, and how do I know the true bitrate? I'm also confused about while using LAME set to VBR 3 on 4 different rippers, I get different results. Generally VBR5 on dBpoweramp seems to give similar bitrates as EAC set to VBR3.

IIRC, WMP's bitrate estimations simply have no basis in reality. It sounds like it's just grabbing the bitrate of the first frame, while everybody else does the right thing and average the bitrate over the entire file. It's easy to do the latter yourself to double-check: Divide the size of the file in bytes by the length in seconds and divide by 256.

Thanks, I figured it had to do with Microsoft. The bitrates on Winamp were identical to those when imported to Media Monkey. I think I'll choose between those two for my main library and forget about WMP.

Just a minor correction, 1024/8 = 128, so you have to divide by 128 not 256.
Well, I just tried this on a LAME 3.96 128kbps CBR file and I got a result of 125.1 kbps, which is somewhat strange... (Foobar2k indicates length of 3:35.267 and the file is 3'445'654 bytes long)

3:35.267 == 215.267 sec
3445654 * 8 == 27565232 bits
27565232 / 215.267 == 128051,3594745130465886550191158 bits/sec
1280051 / 1000 ~= 128 kbps

Sorry, but I thought that "kilo" = 2^10 = 1024 in computer terminology... So it is the same crap as with hard disk/CD/DVD media capacity then.

In telecommunications a kilobit is traditionally 1000 bits.

http://en.wikipedia.org/wiki/Kibibit

Just some trivia: WMP 11 does finally update the bitrate in it's library/display once a non-FhG VBR MP3 track is played to end. If you want to see it: Start a track, jump to the last 10 seconds or so... and when the track ends, a more correct bitrate is displayed and stored in the library. For some reason, Microsoft never updated the WMFSDK code to deal with LAME-like VBR MP3... you get the same 'wrong' average bitrate in Explorer shell, since it calls the same API WMP uses.