I am ripping some older music which was recorded in mono (early Rolling Stones, Beatles, Al Green, etc) with RazorLame using Lame 3.90.3 at --alt-preset standard. They all encode at 128 kbit/s. Why is this? Does not a mono file still contain a great deal of musical information to encode?

My stereo files encode at the expected range (~190 kbit/s, typical 180 ... 220)

Thanks!

John

Yes, of course, but less then TWO sets of musical information, although correlated.

Edit: and beside that those older recording are probably lacking in spectrum...

Edit2: and you'll probably want to enocode them as MONO (-m m)

Sergio

Yeah. Basically its a combination of low fidelity of early recordings plus the fact you only have one channel to encode.

Keep in mind that --alt-preset standard is set to a minimum bitrate of 128 kbps. It will only go lower for digital silence, which it will encode at 32 kbps.

If you want it to go lower than 128 kbps, you'll have to lower the minimum bitrate with the -b switch. Example: --alt-preset standard -b 64, where 64 kbps is your desired minimum bitrate. Make sure you use a lowercase b, an uppercase B sets the maximum bitrate.

Edit:

I just realized that you seem surprised that the bitrate is so low. I originally thought you were surprised that it was not lower.

Also, I should clarify that I am not recommending 64 kbps as the "desired" minimum bitrate for a file encoded in mono. It may be safe to let it go that low, but I make no guarantees. Personally, I use -b 96 on all of my --alt-preset standard encodes, regardless of whether or not they are mono. I see it as a compromise between caution and efficiency that accomodates both files that require high bitrates for transparency and files that encode well at a lower bitrate (mono, for example).

Yes, I was suprised they were all exactly 128 kbit/s. I was thinking they might vary in bit rate like the stereo LAME aps encoded files do.

I am assuming that the regular alt-preset standard is fine for mono recordings. I am not really concerned with file size for mp3s.

John