Article about Cubase Audio and some music questions. Published in Atari Magasinet #1, 1998 (swedish magazine). Translated into english by the author.


Learn some more about digital recording

This time I'll take care of a couple of reader questions and I'll describe the offline-functions in CAF, as well as taking a dip in the pool in cubase Audio...

First of all, I'll express my condolences and say that I'm part of the big lot of people who miss Dag Dao after his unexpected demise and I hope he's better off where he is now. Sad things happen from time to time, but life has to go on for the rest of us, regardless of how bad it feels.

Now, let's continue the article series where I try to teach some things about strange things in the music world. This time it's about Cubase Audio, just like last time, but focusing on other special functions in the program - but first over to some questions I've received.

-? Sometimes I get a sort of chorus effect when I record the synth (but it doesn't appear when I replay what I just recorded). What's wrong?

-! The chorus effect comes because you actually play the same note twice when recording (strange but true). The problem is that the sound is played once directly when you strike the key - but at the same time, the note is sent to the computer where it's sent back to the synth once more and gets played again at the same time.
How about a solution? Ok - either you have to find a menu item in the synth where you can choose "local on/off" (should be set to off when you're working with a sequencer, but on when you want to play live without a computer connected). An alternative is to go to the Cubase menu "Options" - "Midi setup" and choose to turn off midi thru on the synth's midi channel.

-? Why can't I choose 32kHz when recording audio? Many DAT's use this sample frequency to save place on the DAT tapes.

-! I suspect you haven't dared to try it since it's not available in the audio setup menu at analog recording. 32kHz is actually supported by Cubase Audio, but only if you have a digital input source which provides the correct clock (for instance a DAT). You can't choose 32kHz if you want to record analog signals with the A/D setting though.

-? Why do I get an error message saying "No (or instable) External sample clock!" when I start CAF?

-! It may be one of three causes; No incoming external clock is present and FDI (or an ADAT) input is chosen in the "Hardware setup" menu (if you've connected a DAT to the S/Pdif interface, you may have forgotten to switch it on - or forgot to connect a digital cable); You may have managed to get a digital loop by connecting both digital in and out at the same time (this is possible if your DAT doesn't break the connection automatically between the input and output); The third and least probable cause is that the S/Pdif interface is broken.

-? Why are negative values shown in the "Free events" info in CAF after I expanded the Ram from 4 to 14MB?

-! That's really a good question! I've told both the swedish distributor and Steinberg themselves about this bug, but it hasn't been corrected yet. Everything works nicely, but the value shown as free events is wrong - irritating but completely harmless.

So far the questions this time - now over to other interesting things, like the offline functions in CAF.

Offline
Offline means you make adjustments on the hard disk and not in real time. You have to choose the source file and a destination folder. When you've chosen the file you'll get some info about it, like for instance size, if it's stereo or mono and which sample frequency it's recorded with. If you need to, you're free to make new folders to get some structure in your work. What happens with the files when you use the various functions? Everything's shortly described in the CAF users' manual, but I'll try to explain some of them a little better here.

Timestretch
This is a function which may be useful in some situations, but first a word of caution. Timestretch doesn't work well with all hard disks for some reason and on some it doesn't even work at all! Besides, it's a perfect way of destroying a good recording if you don't make very small adjustments. What's the meaning of the effect then? It's used when you want to make a recording a little longer or shorter without changing the pitch. The parameters that may be given are time, tempo (in PBM) and samples. I guess it's most useful if you work with drumloops that are located on a sampling CD but have the wrong tempo. Then you just change the tempo to the needed one. The function is very easy to use, but often takes long time to process - typically about 2.5 times the original time.

8->16 tracks
This function converts all chosen files from uncompressed format to the compressed 16-track format, so you can continue if you run out of tracks.

16->8 tracks
Like the previous, but the other way around. An example of the usefulness of these two functions is if you record a lot of backing vocals in the 16-track mode and want the lead song in the full DAT-quality of the 8-track mode. Then you'll simply mix down the backing tracks to a little fewer tracks and convert those to the 8-track format. Then you can continue with your work and record the lead vocals. The backing vocals are normally mixed a little further back in the mix than the lead, so the small difference in sound quality won't be noticeable in the final mix.

Stereo->mono
Just what it says - it mixes the left and right channels in a stereo recording into one mono track.

Copy
Hmmm.... What could it be? You copy the chosen file to another location. This may be useful if you want to use the same recording in more than one song and want to have all audio files for a song collected in the same folder - and you won't have the risk of loosing that file if the originating song is erased at some time because you decide not to continue working with it...

Sample rate convert
This function converts between sample frequencies. Preselected are 44.1kHz and 48kHz, but others may be chosen as well if you want to. If your master mix has been recorded at 48kHz, you must convert it to 44.1kHz before you'll be able to burn it on an audio-CD.

Tapepitch
Here you'll get a two-octave keyboard and a fine-adjustment figure. What happens is the same as if you increase or decrease the speed of a tape recorder. That is; at a higher pitch, you'll get a faster speed and at a lower pitch, you'll get a slower speed.

Reverse
Not much to say - it makes the recording replay backwards.

Dither
This function is intended to be used for example after you've made a fade-out, where the sound gets very weak and in the end of the fade, it gets a little strange. The dither function adds some random noise, which actually makes the result sound clearer.

Fade in/out
Here you set the time for a fade, as well as the type of fade you want to use and how accurate it should be.

Normalize
If a recording is too weak, you can use normalization to increase the volume. What happens is that it's first searched though for the highest peak and then the whole file is amplified so that the highest peak gets maximum level and everything else is equally amplified. One thing to keep in mind is that also the noise in amplified to the same amount, so to get the best possible sound quality it may be better to redo the recording rather than using normalization - but if it regards marginal adjustments, the noise increase will probably be neglectable.

Auto to 16
This function takes all 8-track audio files in the source-window and converts them to the 16-track format, placing the new files in a folder named "sixteen". The Pool's references to the audio files is changed to the "sixteen"-folder too. However, you have to activate the 16-track mixer yourself in the arrange-window, but in the "Hardware setup", the mixermap is automatically changed to 16-track.

Select all
What do you think it does?

New folder
Creates a new folder in the destination window.

Delete
Deletes files or folders in the destination window.

Start
The normal operation is that it starts the chosen function...

Cancel
To cancel an ongoing operation, click on the cancel button several times. The destination file isn't deleted automatically - you have to do that yourself with the delete function.

Now all the functions in the Offline-window have been dealt with and it's time for a quick dip in the Pool - should be rather nice in the summer heat... ;)

The audio pool
What is the pool in CAF? Well - here all audio recordings that belong to a song are kept. If you want to listen to a specific file, you can click and hold the small speaker icon in front of the filename (if no speaker is present, you click the small triangle in front of the name and it'll drop down).
If you've used waveforms, you can also click anywhere in the waveform that's seen to the right of all other infor about the recording. You can see various informations about the file, like where it starts, its length and sampling frequency. If there's a file present that doesn't belong to the song, it can be removed by pressing Delete or Backspace. If you want to remove a file completely from the hard disk, you press and hold CTRL and press Backspace. You can also import more audio files if you want to. If you often use the same recordings if different songs, you can save the complete pool to be able to load it into another song - then you won't have to locate all the files one by one. To get an audio file that's imported into the pool transferred to the arrange window, you simply drag it out of the pool window and drop it on an audio track at the right location.

That's about it this time - keep in touch if you have any questions (whether it's about hard disk recording or midi - or other music related things). It can be hard to think of suitable things to write about (especially when things are so obvious as they become when you've worked with things several years), but if I don't get other suggestions I was thinking of saying something about CD-burning in the next issue.
Feel free to take a look at my homepage if you feel like it - there may be some useful information.

Have a good time.
The show must go on!
Claes Holmerup
claes@holmerup.com
www.holmerup.com