Instruction Manual

1246 Dialog Reference
Audio Options dialog—Advanced
disk controller, or a disk controller that does not use DMA transfers,
enabling caching may improve SONAR’s audio performance. Note:
Changes to these settings only take effect when you restart SONAR.
• I/O Buffer Size—This value determines the buffer characteristics for
transfers to and from the disk. Changing this value does not affect
audio latency, but will affect the disk throughput for audio tracks. The
default setting is 128. A higher value causes more audio to be buffered
from the disk ahead of the playback cursor. If you are hearing
consistent dropouts/clicks in your audio and if your project contains
high bit depth (32/64 bit) or high sample rate audio (88.2K or higher), it
may be indicative of a too small I/O buffer size. If so try a higher I/O
buffer size like 256 or 512. If audio problems persist, reset to 128 and
try a different remedy.
Also, if you are playing a large file, and using maximum latency, a too-small
I/O buffer size may cause dropouts or crashes. Try increasing the buffer size
by blocks of 128.
Playback and Recording
• Driver Mode dropdown menu—Select from WDM/KS, ASIO or MME.
Consult your hardware documentation to determine which driver your
hardware uses. WDM/KS drivers are the latest available and typically
have very low latency. MME is an older driver type and has higher
latencies. ASIO drivers also offer lower latency. Your hardware may
have all three driver options. If so, you should try WDM first.
• Dithering—whenever an audio signal is converted from a higher-bit
resolution to a lower resolution, it is necessary to apply dither to avoid
introducing undesirable quantization noise or harmonic distortion into
the signal. The purpose of dither is to reduce the resulting distortion by
adding low-level random noise or “dither” to the audio signal. Different
mathematical calculations are used to generate dither, each method
has advantages and disadvantages depending on the particular
operation. SONAR features the Pow-r dithering process, short for
Psycho-acoustically Optimized Wordlength Reduction, which can
produce lower-bit files that sound indistinguishable from higher-bit
source files. When this option is turned on, SONAR uses dithering
when you export a higher-bit file at a lower resolution, or lower the bit
depth of a project’s audio files by using the Tools-Change Audio
Format command, or when you “render” audio (bounce, freeze, or
apply effects).
This option is turned on whenever the Dithering field has a value other
than None. You can choose bit depths for recording, importing, and