The Vienna Suite Limiter Pro maximizes the apparent volume within the available dynamic range by reducing the distance between average program levels and their associated peaks. Just the right amount of maximization will make your signal seem loud without ever exceeding the available dynamic range, whereas too much limiting will make your signal sound "flat" and unnatural.
Processing at 64-bit floating point resolution, which provides the highest fidelity with no added noise, the comfort of a real-time input/output waveform display combined with an auto-mode for transparent maximization makes it very intuitive to operate.
The Limiter Pro allows for fine-grained control over the linking between audio channels. A stereo limiter usually has its channels linked, not to shift its panorama when peaks occur in only one of the two channels. Surround limiting has different requirements since limiting all channels the same way as done in a stereo limiter would sound unnatural. The Limiter Pro offers a group section, allowing to link the attenuation of channels into groups.
To recreate the operation of a stereo compressor, one could thus set both input channels to the same group, then adjust the GROUP value to 100%, to achieve a full linking in the attenuation of both channels.
For surround purposes, it can be beneficial to link speaker pairs. In a 5.1 setup, you would then set L/R to the same group, and Ls/Rs to the same group, then adjust the GROUP knob to achieve the desired result.
The TOTAL knob acts as an additional group, which all channels are fed into. Combining GROUP linking for speaker pairs and TOTAL linking allows you to adjust your limiting for any surround format.
M/S processing is available for each channel pair (L/R, Ls/Rs etc.). Activating the M/S button for a channel pair M/S-encodes the channels before processing, and M/S-decodes the channels after processing.
Shows the levels of all available input channels. Clicking on the numerical peak displays above the meters resets the peak values.
THRESH: Threshold sets the point at which the limiter starts to affect the input signal. Lowering the threshold setting has the effect of raising the output gain of the signal. The average level of the signal is increased while the limiter assures that the signal will not exceed the ceiling level.
GROUP: Group link. Controls the extent to which channel compression affects other channels within the same group. Assign and select groups in the group section window.
TOTAL: Total link. Controls the extent to which channel compression will be globally linked between all groups.
RELEASE TIME: Controls how long it takes for the limiter to recover from attenuating the signal after it has dropped below the threshold. Values: 10–5000 ms.
AUTO RELEASE: Enables / Disables the manual release slider and lets the limiter control the release time depending on the input signal, resulting in the most transparent limiting possible.
TRUE: Enables True Peak envelope detection - a 16x oversampled detector for more accurate limiting.
Shows the current input (I) and output (O) signals, the applied attenuation (A) as well as the attenuation graph. Each signal can be individually switched on and off with the buttons to the right (I/O/A).
If you need to reduce CPU load, you can reduce the update rate of the attenuation graph (1-240 frames per second).
CEILING: Sets the maximum output of the Limiter Pro.
CLIP: Always clip the output level to 0 dBFS.