Alesis Hammerfall DSP System manual Operation under Asio, Known Problems

13. Operation under ASIO 2.0

13.1 General

Start the ASIO software and select ASIO Hammerfall DSP as the audio I/O device. The 'ASIO system control' button opens the HDSP's Settings dialog (see chapter 11, Configuration).

Hammerfall DSP supports ASIO Direct Monitoring (ADM). Please note that currently Nuendo, Cubase and Logic either do not support ADM completely or error-free.

Using emulated MIDI driv- ers often causes a drift and delay between audio and MIDI. You should use non-emulated (MME) MIDI ports in such a case.

At a sample rate of 88.2 or 96 kHz, the number of channels available at the MADI input and output is halfed.

13.2 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. We recommend to deactivate all PlugIns to verify that these are not the reason for such effects.

Additional hard disk controllers, both on-board and PCI based, aften violate the PCI specs. To achieve the highest throughput they hog the PCI bus, even in their default setting. Thus when working with low latencies heavy drop outs (clicks) are heard. Try to solve this problem by changing the default setting of the controller (for example by reducing the 'PCI Bus Utilization').

When using more than one HDSP system, all units have to be in sync, see chapter 15. Else a periodicly repeated noise will be heared.

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 Hammerfall DSP must be properly configured for Full Duplex operation. As long as SyncCheck (in the Set- tings dialog) only displays Lock instead of Sync, the devices have not been set up properly!

22 User's Guide HDSP MADI © RME