Backing up stems at highest possible quality

[TheElement]

Hi guys,

I need to back up like 50 stems of a project. I will have to solo each channel and export them.

What would be the best quality to export a stem at? (Master chain will be off on each export)

I have a few file options:
Wave
AIFC
AIFF
Windows Media Audio
FLAC
OrggVorbis
Wave 64

Which one would be best quality?

Many thanks!

[andygabrys]

WAV or AIFF at the same bit depth (likely 24) and same sample rate as your session.

all the other formats are compressed formats.

[Cruciform]

What Andy said.

[TheElement]

Thanks. ok went with wave at 32 float. Same as session. However I have a lot of synths running 64bit.

darn edit that..I see session was running at 24 bit but I could have selected 32 float.

[andygabrys]

Best do some research on a 32 bit mix session vs a DAW running running plugins in 64 bit memory addressing mode.

Not the same thing.

Although some plugins do internally over sample, the best you are going to hear them as is the 32 bit depth that your mix session is running at.

[TheElement]

Yeah did some research apparently cubase runs internally at 32 bit whether you select another option or not. don't know why they have it set up like that. Will have to read up on that some more.

I run 64 bit plugins..

[andygabrys]

Yeah did some research apparently cubase runs internally at 32 bit whether you select another option or not. don't know why they have it set up like that. Will have to read up on that some more.

I run 64 bit plugins..

as I know it - what you just said is the collision of all the different worlds of "bit depth".

Session bit depth - the number of steps of resolution in the possible dynamic range of the project. Each bit = 6 dB of dynamic range (don't ask me why, it just does). So 24 bit = 144 dB of dynamic range, which is really more than we could ever hope to use, even for a really sensitive orchestral recording that had incredibly loud and soft parts. And for all modern mixes, we barely use 10 dB of range. For VI's the information is passed around the session at whatever is chosen as the bit depth - Logic is 16 or 24 bit. Pro Tools is 16, 24, or 32 bit. But for audio recordings, unless you have incredibly rare (at this writing) esoteric convertors that work at greater than 24 bit, the audio will also end up as 24 bit audio. Most DAW's convert on the fly for the next part.

Session floating point calculation - most modern DAW's calculate at floating point 32 bit. The theoretical dynamic range of a 32 bit calculation is over 1,000 dB - so that is why unless you are using modeled plugins that have a input and output volume "sweet spot" it doesn't matter if you see red lights on any channel except for the master outs - its not really distorting. There is so much headroom, its just never going to be an issue. except for the master outs. And except for modeled analogue type plugins that are going to sound funny if they are hit with the wrong levels (usually the input level being too hot). Plugins that run at 64 bit might be "oversampled" where the audio stream (at 24 bit or 32 bit) is converted on the fly to 64 bit, the calculations done in the plugin and then the audio is down sampled to 32 bit / 24 bit again to continue its path through the mix engine. Or it could be the next point as well....

Session memory address capability - up to about 5 years ago, all DAWs were running on 32 bit OS. Windows and OS X. Over that time, most manufacturers have recoded their apps to run at 64 bit in 64 bit OS with the resulting apps able to address a huge amount of memory. A 32 bit app could only address a maximum of 4 GB (in Os X and its likely the same in Windows). That meant the maximum size of a project including RAM use for samples plus calculations was 4 GB, and this meant that the actual RAM load for samples was about 2.5 GB (in OS X). Now with 64 bit OS and 64 bit memory address, that ceiling has been lifted. The machines themselves are now able to address virtually unlimited amounts of RAM if its possible to stuff it into a machine. I think the limit is up about 512 GB.

So that is what I was talking about.

[cassmcentee]

Session floating point calculation - most modern DAW's calculate at floating point 32 bit. The theoretical dynamic range of a 32 bit calculation is over 1,000 dB - so that is why unless you are using modeled plugins that have a input and output volume "sweet spot" it doesn't matter if you see red lights on any channel except for the master outs - its not really distorting. There is so much headroom, its just never going to be an issue. except for the master outs.

Andy you are a blessing!
I've wondered about this and now you just answered it for me.
Thank You!
Cass

[mojobone]

Yep, Andy's explanation is on point; 32-bit operating systems meant that people running massive orchestral mockups needed multiple networked computers to represent even a 16-bit sampled orchestra of as little as sixty-odd players. Multiple 8-Port MIDI interfaces were the norm. MOTU made 'em, mostly and powerful MIDI sequencers dominated computer music, whilst most of the serious recording still involved microphones and acoustic spaces.

As a point of order, if you're breaking out every track in your mix, can you still call them stems? To me, a stem is a group of tracks, bussed together for the convenience of either effects processing or mix balance. Maybe also archiving or remixing, but groups, still.

It's important to understand when increasing bit depth buys you something and when it doesn't; I could spend another two hours typing, or you could go buy or borrow Bob Katz' book, Mastering Audio; The Art & The Science.

[VanderBoegh]

Hey Gav, just curious why you'd want to turn off all master bus processing when exporting the stems. Is it for a library, or are you sending the stems to a remix producer? If it's a library, I've always sent the stems complete with all processing on, including the master, so someone on the other end can just stack the stems to create an identical version of my final product. Taking the master processing off wouldn't allow them to do that.

But if you're sending the stems off to another producer, I can see why you'd want to strip them off, so that person can have more control over the mix from their end.

Just curious what the end use of the stems will be!

~~Matt