User`s guide

User's Guide DIGI32 © RME
9
8.4 Recording Digital (Windows MME)
Unlike analog soundcards, which produce empty wave files (or noise) when no input signal is
present, digital I/O cards always need a valid input signal to start recording (this includes the
correct sample frequency as well).
To take this into account, RME has included three unique features in the DIGI32 series: an
error LED for the active digital input in use, a comprehensive I/O signal status display (showing
sample frequency, lock and format) in the Settings dialog, and the protective Check Input func-
tion.
The error LED indicates whether the card gets power and a valid digital input signal. Whenever
an error occurs (wrong input, invalid data, signal transmitting device delivers nothing), the LED
will light red. As soon as a valid input signal is present the LED will turn off. The display of the
sample frequency (see chapter 9, picture Settings) in the Status display offers a similar functi-
on. If no sample frequency can be recognized ‘Out Of Range’ will be shown, in case of an error
detection ‘No Lock’.
If a 48 kHz signal is fed to the input and the application is set to 44.1 kHz, Check Input stops
the system from recording. This prevents faulty takes, which often go unnoticed until later on in
the production. Such tracks appear to have the wrong playback rate - the audio quality as such
is not affected. 'Check Input' may be switched off for vari-speed purposes.
Therefore configuring the software to perform a digital recording is child´s play. After selecting
the required input DIGI32 displays the current sample frequency. This parameter can then
be changed in the application’s audio attributes (or similar) dialog.
The screenshot to the right shows a typical
dialog used for changing basic parameters
such as sample frequency and resolution in
an audio application.
Any bit resolution can be selected, provi-
ding it is supported by both the audio hard-
ware and the software. Even if the input
signal is 24 bit, the application can still be
set to record at 16-bit resolution. The lower
8 bits (and therefore any signals about
96dB below maximum level) are lost entire-
ly. On the other hand, there is nothing to
gain from recording a 16-bit signal at 24-bit
resolution - this would only waste precious space on the hard disk.
It often makes sense to monitor the input signal or send it directly to the output. The DIGI32
series includes a useful input monitor function, which can be set in the RME DIGI Settings
(Output/Automatic). Activating Record or Pause in the application causes the input signal to be
passed directly to the digital and analog output. However, some applications block monitoring
by constantly activating playback, even if the played back track is empty. This is often required
by programs to ensure that timing and punch I/O will work correctly.
8.5 Record while Play
DIGI32 allows the playback of audio data during the recording of further audio data, even at
different sample frequencies. This feature, known as Enhanced Full Duplex or Record while
play, is a must for multitrack harddisk recording, but it has to be supported by the recording
software.