The Hardware Settings dialog

The Hardware Settings dialog of the DSP24 series is used to control the basic driver settings of the audiocard. You call it via External Links [1] (DSP24, DSP24 MK II, DSP24 ADAT) or the Output Mixer [2] (DSP24 Value, DSP24 MEDIA 7.1). The Hardware Settings dialog is also used when you open the ASIO control panel from an ASIO compatible sequencer such as Emagic Logic Audio or Steinberg Cubase VST.

The upper section displays the current version of the driver that is installed. Also you can see the current latency that has been selected for the ASIO 2.0 driver. Below that, you can see the resolution of the converters that are used in your hardware installation. At the moment only solutions with 24bit converters are available from ST Audio. If you use the DSP24 card with an older H-BUS [3] converter unit from Hoontech [4], a lower number might be displayed here. If the DSP24 card is used without any external box, the display will be 24-bit anyway (because you can play and record 24bit signals over the S/PDIF and AES/EBU I/O ports). The DSP24 MK II, DSP24 Value and DSP24 MEDIA 7.1 cards are using a 24bit converter anyway.

Clock Setting

The Clock Setting tab controls the samplerate and bit-deepth (resolution) the card operates.

Under Audio Data Handling you can determine if the card allows you to playback and record with a bit-deepth that us higher as the converter resolution (displayed above). As the converter resolution is usually 24-bit, it does not matter in most situation what is selected here. The default setting is Allow operation when data exceeds converter resolution. This might be important if your (older) external box just uses 18bit ADC/DAC chips for example.

The Clock and Sample Rates (Hertz) section allows you to select the source of the clock for the DSP24 card. You can select between Internal Master Clock and External Master Clock. Make sure to select External Master Clock only if you will be recording or monitoring from the digital input of the card (via the optional bracket of the DSP24 Value, via XG DB I [5] on the DSP24 / DSP24 MK II or via the external box on the DSP24 MEDIA 7.1). In that case, the device that is connected to the digital input will supply the clock for all operations you perform with the card. If you select Internal Master Clock (default), the clock generator on the card will generate the samplerate. You will have problems with noise and clicks in your audio signal if you have selected external clock without an active device (DAT, MD, digital mixer, etc.) on the digital input. Also you will have similar problems when you want to record a signal from the digital input with the card set to internal clock.

The section of the Hardware Settings dialog also shows the current samplerate of the card, which has been set by your application software. The samplerate selected here will be used for all functions of the card. This includes the digital output, so if you sync an external device (MD, DAT, digital mixer, etc.) to the DSP24 card, it will use the clock that is selected here. The Rate Locked option is used to force the card to a specific samplerate. It is disabled by default (which is also our recomendation) which automatically allows your application software access to all supported samplerates. When the option is enabled, your software will only work with the selected samplerate. This means that any application that attempts to use the driver at a different sampleate will show an error message. Reset Rate After Play should be selected when you want that the samplerate return to a specific setting when no software is using the card for playback or recording. This is especially important if your external device that is connected to the digital output of the card is synched to the DSP24 card. If you just use the analog outputs, the selected samplerate and the Reset Rate After Play option are not important when the card is not used by your software at the moment.

Device Setting

The Device Setting tab controls the options needed for playback and recording.

Under Waveout Driver you can select the MME/ASIO buffer size (latency). The smaller the selected value is, the smaller the resulting latency of the ASIO driver will be (and the other way round). You might notice the latency when you perform some action inside your ASIO application (e.g. you are using a VST instrument in Cubase VST): the result of your action will be audible with a certain delay - the latency. With the current drivers (v6.x for Windows 9x/Me), the latency can be lowered to 5.5ms at 44.1kHz when the smallest value (256) is selected. Older versions of the Windows 9x/Me driver allow you to lower the latency to 7.5ms at 44.1kHz. The latest Windows 2000/XP drivers (WDM) allow you to set even smaller values, however this might affect system performance. If you increase the samplerate, the latency will be automatically lower (e.g. 88.2kHz will give you exactly halve of the latency time as 44.1kHz with the same buffer size).

You have to keep in mind that a smaller latency also increases the PC utilization and might have some influence on the performance (very much depending on the PC configuration). A buffer size that is too small may result in clicks or drop outs in the audio signal. Larger buffers could prevent this. This buffer size should be set in the this dialog before you launch your music software. In some ASIO applications it is important to re-launch the software even if you have changed the buffer size via the ASIO control panel inside the application. We strongly recommend this for Logic SoundTrack24 [6] and other versions of Logic Audio from Emagic for example but it is also better for all other ASIO applications.

The WaveDriver setting under the MME/ASIO Buffer allows you to change the latency of the MME driver in ms for Windows 2000/XP and v5.x drivers for Windows 9x/Me. Not all versions of the driver will use this setting.

The MME drivers of the DSP24 card automatically synchronize the beginning of recording and playback for all audio devices. For some software applications that are using several MME devices simultaneously, you should select Single and In-Sync under MultiTrack Wave Drivers to ensure that all channels will begin playback and/or recording at exactly the same time. Otherwise select Independent - this allows you to use the cards MME devices with more than one application at the same time.

Multiclient Support (Device Mixing)

The DeviceMixing (MME/ASIO/GSIF) section allows you to assign individual stereo output pairs to a certain driver model to be able to use several different programs (e.g. GigaSampler-/Studio and a Audio-/MIDI-Sequencer like Logic Audio or Cubase VST) at the same time. Please note that you need at least revision 6.x of the driver for Windows 9x/Me to use this function. Under Windows 2000/XP, you need drivers that have been released after June 2002.

Multiclient support is available for MME drivers (e.g. usually used by WaveLab, Sound Forge, Cool Edit, Cakewalk, ...), the ASIO driver (e.g. used by Logic, Cubase VST, Reaktor, ...) and the GSIF driver (used by GigaSampler and GigaStudio). This even allows you to use GSIF software that was designed to run separatly on a system without other software parallel to other audio programs.

The example on the picture on the right shows a setup where the output channels 1~4 and the S/PDIF output channels are assigned to the ASIO driver. Channels 5~8 are assigned to GSIF. This setup is done before you start GigaSampler/-Studio and your ASIO application. It is not possible to change DeviceMixing setttings after you have launched your audio application(s).

The last column of the section displays the resulting channel numbers. In this setup, the S/PDIF output channel (which is usually 9,10) has been assigned to channel 5,6 of the ASIO driver. Also, the channels 5~8 are assigned to channels 1~4 of the GSIF driver. This assignment is needed, because the DSP24 driver simulates a normal audiocard interface in the different driver models for the applications. This prevents compatibility issues with certain audio applications.

It is not recommended to change this setup often, as the different applications will also save the channel assignments internally. If you change the settings in the DeviceMixing section, it is wise to double-check the soundcard setup inside the audio apps you are using after that. These options have been invented because of the demand from the users to be able to use GigaSampler/Studio simultanously to famous Audio-/MIDI-Sequencer software. We strongly recommend to use at least v1.64 of GigaSampler or v2.2 of GigaStudio in order to use the multiclient support under Windows 9x/Me. The performance may not be as good when using earlier versions of the software. GigaStudio 2.2 and above will give you best performance. Under Windows 2000/XP, you need at least v2.5 of GigaStudio. GigaSampler is not supported under Windows 2000/XP.

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last updated: 07/11/2002 author: Claus Riethmüller