RME HDSP 9632 [21/87] Operation and usage

User's Guide HDSP System HDSP 9632 © RME

12. Operation and Usage

12.1 Playback

The HDSP system can play back audio data only in supported modes (channels, PCM) and

formats (sample rate, bit resolution). Otherwise an error message appears (for example at 22

kHz and 8 bit).

In the audio application being used, HDSP must be selected as output device. This can often be

found in the Options, Preferences or Settings menus under Playback Device, Audio Devices,

Audio etc.

We strongly recommend switching off all system sounds (via >Control Panel /Sounds<). Also

HDSP should not be the Preferred Device for playback, as this could cause loss of synchroniza-

tion and unwanted noises. If you feel you cannot do without system sounds, you should con-

sider buying a cheap Blaster clone and select this as Preferred Device in >Control Panel

/Multimedia /Audio<.

The screenshot shows a

typical configuration dialog

of a (stereo) wave editor.

After selecting a device,

audio data is sent to an

analog or digital (ADAT /

SPDIF) port, depending

on which has been se-

lected as playback device.

Increasing the number

and/or size of audio buff-

ers may prevent the audio

signal from breaking up,

but also increases latency

i.e. output is delayed. For

synchronized playback of

audio and MIDI (or simi-

lar), be sure to activate the

checkbox ‘Get position

from audio driver’.

The HDSP system’s ADAT optical interface allows sample rates of up to 96 kHz using a stan-

dard ADAT recorder. Single-channel data at this frequency requires two ADAT channels,

achieved using the Sample Multiplexing technique. This reduces the number of available ADAT

channels from 8 to 4. Under Windows MME, channels are routed to ADAT devices in double-

speed mode as follows:

• Only stereo pairs (1+2) and (3+4) of the ADAT port are available

This kind of implementation allows a problem-free usage of the ADAT port in both Single and

Double Speed, as the routing doesn't change. However, the hardware spreads the data differ-

ently: Channel 1 is transmitted via channels 1 and 2, channel 2 via 3 and 4 etc.

Please refer to the diagram in chapter 18.2. Routing for record and playback is identical.