ALESIS Hammerfall DSP System - Manual (Page 34)

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User's Guide HDSP MADI © RME
20.3 Supported Sample Rates
RME's Mac OS X driver supports all sampling frequencies provided by the hardware. Besides
96 kHz this also includes 32 kHz and 64 kHz.
But not every software will support all the hardware's sample rates. For example Spark does not
display 32 kHz and 64 kHz. The hardware's capabilities can easily be verified in the Audio MIDI
Setup. Select Audio devices under Properties of: and choose the Hammerfall DSP. A click on
Format will list the supported sample frequencies.
If the unit is in clock mode Master, selecting a sample rate will immediately set the device to
this frequency, which can be verified in the HDSP's settings dialog (System Clock). Format thus
allows you to activate any sampling frequency quickly and easily.
20.4 Repairing Disk Permissions
Repairing permission can solve problems with the installation process - plus many others. To do
this, launch Disk Utility located in Utilities. Select your system drive in the drive/volume list to
the left. The First Aid tab to the right now allows you to check and repair disk permissions.
20.5 PCI card and PCI slot compatibility
Unfortunately not every RME card will work in every PCI slot of an Apple computer. To our
knowledge, the current Hammerfall DSP systems can be used in any PCI slot of all G4 and G5
models. In case additional PCI cards of any manufacturer are used, it might happen that the
RME card is no longer found by the system. Swapping cards between slots can be helpful in
this case.
20.6 Various Information
The driver requires 10.2.8 or higher. Older versions of OS X are not and will not be supported.
Via >System Preferences/ Audio-MIDI Setup< the hardware can be configured for the system
wide usage. Programs that don't support card or channel selection will use the device selected
as Standard-Input and Standard-Output. (Soundstudio, Mplayer, Amplitube etc.).
In the lower part of the window, the audio hardware's capabilities are shown and can be
changed in some cases. On the record side no changes are possible. Programs that don't sup-
port channel selection will always use channels 1/2, the first stereo pair.
Since OS X 10.3 playback can be configured freely and to any of the available playback chan-
nels. This is done via Speaker Setup. Even multichannel playback (Surround, DVD Player) can
be set up easily.
OS X supports more than one audio device. Their simultaneous usage within one program had
been limited to Motu's Digital Performer until 10.3.9. Since 10.4 (Tiger) Core Audio offers the
function Aggregate Devices, which allows to combine several devices into one, so that a multi-
device operation is now possible with any software.
The Hammerfall DSP driver adds a number to each unit, so they are fully accessible in any
multicard-capable software.
Our experience so far is that using more than one HDSP MADI will work only on dedicated
server systems having multiple PCI busses. The PCI bus load of 128 channels plus the realtime
behaviour necessary for audio are critical parameters. A usage of two cards at full track count is
therefore difficult to achieve on current Mac computers. See chapter 30.7, PCI – Performance.