Large project, advise please

[powadha]

I'm converting a large amount of DAT tapes for a university. About 400 tapes need to be converted. On the tapes are interviews with children that need to be trancribed. The DAT tapes contain 60 minutes of speech which I want to convert to MP3.
I've been testing with different settings on LAME encoding but I just cant get it right (or small enough). As you understand I want to save as much space as possible without loosing too much quality. All the MP3s will be burned to CD-ROM so every bit won is great. MP3pro might be an option (I haven't had a chance to test it on the trancribe software if it can play that).
Do you have any suggestions what settings I could go for and what encoder would be best? I have power pack installed. The DAT tapes give a .AIFF file if I read it to pc. Best I could do was from 12.6MB, 5 minutes to 1.71MB on 48 kbps / 32 kHz, which would give me about 33 DATs on a 700 MB rom. As far as amount of DAT tapes to ROM this is good enough, the sound went a bit 'metal' though. A slightly higher setting gave a file twice as big and that's too much.
A very long post but I hope you have taken the time to read it and hopefully have some advice for me on encoding and settings.

Regards

[Spoon]

It is a tough one - you might first want to convert them to wave - scale the frequency right down, perhaps 16khz - use the 'Professional freq conversion' on dMC Configuration. Then go from there into mp3PRO, or mp3, or even Ogg Vorbis...

[powadha]

Thanx for your advise. I made some changes to my setup and started to test Sound Forge 6.0 to read in Wave directly from DAT true the line-out of the DAT and Line-in on the SB live 5.1. For now the results are quite good but I might try the optional SBIII (I think its called) that gives me a spdif connection to the DAT directly and might increase the quality (any ideas on that?) Since the recordings are done in mono only the left channel is used for recording.
I read some where that since my DAT records in 44.1 in need to read in the Wave at 44.1 as well. Is that true? I would be a time saver if I could go to say 16 at the first take and only convert it to mp3 after. I'm trying to find time savers more then space since it turns out that the project is going for a second set of interviews which means double the tapes (ahhhhh) I need to get this done really good since they are going to reuse the DAT tapes I converted to cd rom (right, no pressure at al, lol)
For now I try your settings and see what I get. Rotten thing is that I have to play all the DATs in real time (Why didn't they use MD???) since DAT cant play at higher speeds I think (anyone an idea on that one)
Again a long post but since there's a lot of knowledge around here I give it a go. I tried some DAT-forums but no help from there (anyone know a good friendly forum on DAT?)

Loads of regards!

[Spoon]

I always thought DAT was 48KHz

[powadha]

You can switch it from 48 to 44.1 (Tascam DA-P1) on most DAT recorders. The tapes are recorded on 44.1.