Sonnox Fraunhofer Codec Toolbox - Manual (Page 13)

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6.1.6 Internal Buffer Sizes
For most codecs, the plug-in uses internal buffer sizes of 1024 samples for up to 48kHz operation
and 2048 samples for 48kHz. We recommend that the buffer sizes of the sound card, and thus of
the host application, are set to match these figures. Buffer sizes for the HE-AAC and HE-AAC v2
codecs are twice these figures (so 2048 samples for up to 48kHz operation).
The plug-in runs most efficiently and smoothly when supplied with sample buffers of 1024 samples
or multiples thereof. Smaller buffer sizes than 1024 samples can cause CPU spiking, which
different hosts may have a different tolerance to.
6.2 Creating your Final Mix
When working on finalising your mix or master processing, insert the Toolbox plug-in as the last
insert on your master output.
The Toolbox plug-in should be placed after your final limiter and dithering processor.
Use the NMR METER to help assess the areas of your mix that may be affected by the effects of
lossy compression. You may adjust areas of your mix, or adjust your Codec, Mode and Bit Rate
until you find a suitable balance between audio quality and amount of data compression.
(Remember, lower bit rates equate to greater data compression).
Play your mix or master from start to finish.
It is important to pay attention to the bit-stream OVERS meter. If this meter registers greater than 0
dBFS (red), it indicates that your mix or master has the potential to clip the DAC of the end-user’s
playback device, leading to undesirable distortion.
The sound of hard or soft clipping can be desirable for certain programme material. However in
such cases, it is much wiser to impart this desired sound by using a suitable clipping processor
prior to your final dither processing. This will ensure sonic consistency across various playback
devices.
To accommodate for bit-stream OVERS, simply reduce signal level prior to your final dither
processing, by enough to prevent the Toolbox plug-in OVERS meter from registering greater than 0
dBFS.
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