Known Problems; Using More Than One Hammerfall Dsp - RME Audio DSP System Multiface User Manual

10.3 Known Problems

If a computer does not provide sufficient CPU-power and/or sufficient PCI-bus transfer rates,
then drop outs, crackling and noise will appear. Raising the buffer size in the Settings dialog of
the HDSP system helps in most cases. It is also recommended to deactivate all PlugIns to verify
that these are not the reason for such effects.
Another common source of trouble is incorrect synchronization. ASIO does not support asyn-
chronous operation, which means that the input and output signals not only have to use the
same sample frequency, but also have to be in sync. All devices connected to the Multiface
must be properly configured for Full Duplex operation. As long as SyncCheck (in the Settings
dialog) only displays Lock instead of Sync, the devices have not been set up properly!
The same applies when using more than one HDSP system - they all have to be in sync. Else a
periodically repeated noise will be heard.
RME supports ASIO Direct Monitoring (ADM). Please note that not all programs support ADM
completely or error-free. The most often reported problem is the wrong behaviour of panorama
in a stereo channel.
In case of a drift between audio and MIDI, or in case of a fixed deviation (MIDI notes placed
close before or behind the correct position), the settings in Cubase/Nuendo have to be
changed. At the time of print the option 'Use System Timestamp' should be activated. The
HDSP system supports both MME MIDI and DirectMusic MIDI. It depends on the used applica-
tion which one will work better.

11. Using more than one Hammerfall DSP

The current drivers support operation of up to three HDSPe AIO. All cards of the HDSP and
HDSPe system use the same driver, therefore can be used at the same time. All units have to
be in sync, i.e. have to receive valid sync information either via word clock or by using AutoSync
and feeding synchronized signals.
• If one of the HDSP systems is set to clock mode Master, all others have to be set to clock
mode Slave, and have to be synced from the master, for example by feeding word clock.
The clock modes of all units have to be set up correctly in their Settings dialogs.
• If all units are fed with a synchronous clock, i.e. all units show Sync in their Settings dialog,
all channels can be used at once. This is especially easy to handle under ASIO, as the ASIO
driver presents all units as one.
Note: TotalMix is part of the hardware of each HDSP system. Up to three mixers are available,
but these are separated and can't interchange data. Therefore a global mixer for all units is not
possible.
22
User's Guide HDSP System Multiface II © RME