Plug-in upsampling on bounce/freeze/export

Some plug-ins that can produce unwanted artifacts when running at lower sample rates. This typically applies to plug-ins and virtual instruments that don’t oversample internally. Amp sims and synths are affected the most, but so are dynamics processors and some reverbs.

While you can work around these problems by using higher project sample rates like 88.2 kHz or 96 kHz, doing so can also add CPU load to the project due to the higher data bandwidth.

SONAR provides another solution, which lets you specify whether a VST or DirectX plug-in effect or instrument should be resampled at 2x the project sample rate when bouncing, rendering, freezing, exporting, etc., or during playback. This allows you to gain the benefits of running at a higher sample rate in a standard 44.1KHz project. This process happens automatically and behind the scenes.

To globally enable/disable upsampling for a plug-in, click the FX icon in the upper left corner of a plug-in window, and select Upsample on Render or Upsample on Playback on the drop-down menu. These options globally persists for all instances of the plug-in in all projects, so it only needs to be set once per plug-in.

When selected, SONAR will upsample the incoming audio to 2x the project sample rate, process the plug-in at the new rate, and downsample the resulting output to the project sample rate.

Upsampling provides several benefits:

Allows plug-ins to process the source material at a higher level of precision.

Drastically reduces the likelihood of intersample clipping when you maximize the level.

Undesirable digital artifacts are shifted much further outside the range of human hearing.

Phase shift is drastically reduced.

Benefit from 96kHz processing without the hard disk and CPU strain that recording at 96kHz produces.

Non-linear processors, such as EQ and compressors, benefit from upsampling to lessen aliasing of high frequency components.

Upsampling settings

The per plug-in upsample settings are stored in the Audi.ini file, under the key [PluginUpsampler] like this:

[PluginUpsampler]

{141AC902-4357-626C-424F-4F5354317E31}.EnableFlags=1

{141AC902-4357-626C-424F-4F5354317E31}.SampleRate=96000

A plug-in is only listed in the Audi.ini file after you have toggled its Upsample on Render or Upsample on Playback option. The long number string is the plug-in’s CLSID, and is unique for each plug-in.

The {Plug-in CLSID}.EnableFlags= variable specifies whether resampling is applied. It corresponds to the Upsample on Render and Upsample on Playback settings in SONAR’s UI. Valid values are as follows:

0 = Disables upsampling

1 = Enables upsampling at render time

2 = Enables upsampling during playback

3 = Enables upsampling at render time and during playback

The {Plug-in CLSID}.SampleRate= variable specifies the per plug-in upsampling rate. It defaults to a value of 0 (zero), which means “resample at twice the project sample rate”. The max sample rate is 384000 Hz. This variable is not stored in the Audi.ini file by default, so it must be manually added if you want to change a plug-in’s upsample rate (Tip: copy the CLSID from the corresponding EnableFlags= variable).

To globally bypass plug-in upsampling

To globally enable/disable plug-in upsampling for plug-ins that already have upsampling enabled, click the Enable/Bypass Plug-In Upsampling button in the Control Bar’s Mix module. Upsampling is enabled when the button is lit.

Figure 372. The Mix module.

 

See:

Effects parameters

How to use real-time effects

Applying audio effects

Applying MIDI effects

Bypassing effects globally

Using the Plug-in Browser

Effects chains