PreSonus FireStudio - Manual (Page 26)

CONTROLS AND CONNECTIONS
23 | PreSonus 2008
3.1.2 Launch Window
From the Launch Window, you can set all the basic controls for your FireStudio.
 Sample Rate Selector
Changes FireStudio Sample Rate
You can set the sample rate to 44.1, 48, 88.2, or 96 kHz. A higher sample rate
will increase the fidelity of the recording but will increase the file size and the
amount of system resources necessary to process the audio.
 Buffer Size Selector Changes the FireStudio Buffer Size (Windows PCs Only)
You can set the buffer size from 64 to 4,096 samples. The buffer size determines
the latency, which is the roundtrip time it takes audio data to be converted from
analog to digital and back to analog. As a general rule, the higher the buffer size,
the better the system performance, but the less playable virtual instruments
become. In general, 512 samples (11 to 12 milliseconds) will provide you with a
buffer that is large enough for optimum system performance, but small enough to
be unobtrusive. You should set your buffer size and sample rate prior to
launching your host applciation.
On Macintosh, the buffer size is set from inside your host application.
 Operation Mode Changes How the FireStudio Driver’s Buffer Size is Set
 Normal Mode. Input and Output buffers are both identical to the Buffer
Size setting.
 Safe Modes 1-3. Increases the Output buffer size for added stability.
 Clocksource
Changes the Clock Source for the FireStudio
The clock source setting will determine the port from which the FireStudio is
receiving word-clock information. This keeps the FireStudio in sync with other
digital devices. You can choose between Internal, BNC, S/PDIF, ADAT 1, or
ADAT 2.
In general, you will want the FireStudio to be your master clock, in which case
you should set the clock to "FireStudio - Master." This setting also means that
your FireStudio is generating word clock and sending this information out of its
digital outputs.
If you want the FireStudio to receive sync from an external device, choose the
digital input to which the external device is connected (i.e. S/PDIF, ADAT, or
BNC Wordclock). The FireStudio's sync light will flash from blue to red. When
the FireStudio is in sync, the light will be blue.
Please note: When slaved to an external clock, the FireStudio will not
automatically change its sample rate to match the external clock. As a result, it
may fail to sync to the clock source. If your FireStudio is not syncing to an
external source, make sure that both your master device and the FireStudio are
set to the same sample rate.