Bit-Rate and Sampling Frequency change of a session???

[Patill]

Hey,

I would like to change the bit-rate from 16 bit to 24 bit and the sampling rate from 44.1 kHz to 48 kHz, since this is recommended when you record a CD. I thought I go woth the CD defaults, but I´m propably wrong .


I can re-record the audio material, so what´s left in the sessions is just instrument tracks with some RATS instruments (Battery and Xpand2).

Is it possible to change it easily? How do I do that?

[JonesH]

I'd create a new session @ 24bit/44.1 kHz and then use Import session data. Don't runt 48k sampling rate when the end product is going to CD, you just need to make sample rate conversions from 48k to 44.1k.

[1ace1]

You can also go to the 'Save Copy As' function and change the settings of the session there (the new settings will be in the saved copy).

A

[Patill]

ah ok.

I´ll try that, but somebody´s gotta help me out, I once tried saving a copy and some stuff was gone after .

I´d like to have it as a copy so I can delete the original without loosing stuff.


Now a very important question:
Is there any quality loss when I do that??? I mean saving a copy with 24 bit?

[1ace1]

the bits shouldn't make a big difference (it just will be representative of a 16 bit recording) but upsampling just adds samples that are already there to fill in the gaps so it is destructive to the raw data. resampling would be the best way to go but again would be somewhat destructive. rerecording would be ideal!

A

[allstaar]

Originally Posted by Patill

I´ll try that, but somebody´s gotta help me out, I once tried saving a copy and some stuff was gone after .

I´d like to have it as a copy so I can delete the original without loosing stuff.

If you were saving a session copy at the same bit depth and sample rate, you'd need to make sure it copies all audio files as it is an option for it to reference the audio files in the current session. To avoid this, check "copy all audio files" in the save session copy window.

If you're creating a session copy in either a different bit depth or sample rate, Protools has to create new files so always copies all audio files. In your current scenario, this is what would happen.

After you've done a session copy, it may be worth moving the old session to the trash temporarily and then opening the new one to make sure it has all the audio files it needs. Protools cannot reference audio files in the trash, so this is a way to check, if you're at all worried.

[albee1952]

Excellent advice above. I also agree that recording at 44.1 saves a sample rate conversion(although there are some that feel the conversion can smooth off rough edges). I usually work at 44.1K and always(unless someone else started a project) record at 24 bit for the increased headroom. That allows you to be more relaxed with your record levels(good for avoiding clipping with that singer that has no mic technique). Just remember that a 24 bit file will need to be dithered to 16 bits for burning audio CD's.

[Patill]

Thank you everybody, have big work to do now

Originally Posted by 1ace1

the bits shouldn't make a big difference (it just will be representative of a 16 bit recording) but upsampling just adds samples that are already there to fill in the gaps so it is destructive to the raw data. resampling would be the best way to go but again would be somewhat destructive. rerecording would be ideal!

A

Yes, I´ll rerecord the audio files, that´s no problem. But what about the instrument tracks? They shouldn´t have any quality loss at all right? Or do I have to change something there, too?

[1ace1]

They SHOULD be fine as far as I'm aware.

A