Audio Setup - E-Mu ProteusX Operation Manual

Sample Buffers
This control allocates the amount of RAM that will be set aside for Proteus X (in other
words, the number of the largest complete samples in the bank that can be kept in the
RAM cache). As samples are played, they are loaded from the hard disk into RAM. If you
play those samples again and they are already in RAM, they don't have to be reloaded.
This control sets the size of the RAM cache that will be kept and lowers disk access at the
expense of RAM.
To Optimize the Performance and Polyphony of your System:
The polyphony of the Proteus X is dependent on a variety of factors including:
• The Pre-roll setting (if streaming is enabled).
• The Sample Buffers setting (if streaming is enabled).
• The CPU Cap setting.
• The bit depth of your samples —16 or 24 bits (24 bits = fewer voices)
• The sample rate of the audio hardware—44.1kHz, 48kHz, 96kHz.
• The speed of your computer —CPU speed, RAM and hard disk access time.
Begin by choosing 44.1kHz or 48.kHz as your output sample rate.
The software-based filters can eat up CPU cycles and reduce polyphony.
Cost of Filters on Voice Count
No Filter No additional CPU load.
2nd Order Additional CPU load comparable to playing another 1/2 sample.
4th Order Additional CPU load comparable to playing another 3/4 sample.
6th Order Additional CPU load is comparable to playing 1 more sample.
(polyphony is divided by 2)
12th Order Additional CPU load comparable to playing 2 more samples.
(polyphony is divided by 3)
Synthesizer parameters also use CPU cycles. When creating presets, feel free to use
modulation cords as needed, but don't leave cords half connected if you aren't using
them since these patch settings waste CPU cycles. Turn off both the source and desti-
nation of unused cords.

Audio Setup

These controls let you set audio quality parameters related to Proteus X and your sound
card.
Type
You have a choice to use either Direct Sound or ASIO audio drivers. If you have another
high quality sound card installed in your system, it will be shown in this field.
ASIO (Audio Stream Input/Output) is a cross-platform, multi-channel audio transfer
protocol. ASIO is fast and supports 16-bit and 24-bit data width. To use Proteus X with
the E-MU Digital Audio System, select the E-MU ASIO driver.
Selecting Direct Sound uses the audio output device specified in the control panel of
your computer. In general using Direct Sound is not recommended because of speed
and latency issues.
E-MU Systems
1 - Introduction & Installation
Setting up the Preferences
17