How Do I Set My Software's I/O Buffer; Soft Limit; When To Use Soft Limit - Apogee Ensemble Thunderbolt User Manual

Apogee Ensemble Thunderbolt | User's Guide

How do I set my software's I/O buffer?

The I/O Buffer setting found in most audio software is one of the most crucial, but often ignored, settings in a
Mac-based recording system�
When choosing a buffer setting, a compromise between the latency through the application and the amount of
computer processor power accessible to the application must be made�
A lower Buffer setting results in lower latency but less available processing power. If the application can't access
enough processor power, processor overruns may occur, resulting in audible clicks and pops or error messages
that interrupt playback and recording�
A higher Buffer setting, on the other hand, results in greater amount of accessible processor power (i.e. less
chance of overruns) but increases the latency� Determining the best setting requires some trial-and-error in order
to find the best compromise.
Keep in mind that as tracks and plug-ins are added to a software session, processor requirements increase�
Thus, the buffer setting that works during the early stages of a session might result in processor overruns during
later stages�
The best strategy is to set the buffer to a lower setting during recording and accept certain limitations on plug-in
usage, and then raise the buffer during mixing to utilize the computer's full processor power when latency isn't
an issue�
With the processing power of today's Macs, you may find that adjustment of the Buffer isn't necessary, and you
can leave it at a setting for low latency and still access a sufficient amount of processing power when adding
tracks and plug-ins� If you do encounter clicks, pops or software errors, don't hesitate to experiment with the
Buffer setting.

Soft Limit

Soft Limit is Apogeeʼs proprietary analog process for taming transients before A/D conversion. By gently
rounding transients in a transparent manner, itʼs possible to maximize level BEFORE the A/D conversion stage
and prevent unwanted distortion from clipping�

When to use Soft Limit

Soft Limit is an analog process that instantaneously rounds transient peaks beginning at -4dbfs� For all intents
and purposes attack and release times may be considered instantaneous� As with any peak reduction device
working at such fast time constants, Soft Limit is most effective with signals whose peak information is much
greater than its average (or RMS) information, such as drums, percussion and plucked instruments� Soft Limit
may not be the appropriate choice for limiting signals whose crest factor (peak to RMS ratio) is low, such as bass
or organ�
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