The Multiband AGC section has two primary functions.

The first is to build RMS energy which increases perceived loudness and delivers a more "processed" sound when compared to the original source material.

The second is to provide spectral consistency to the processed audio. This is often called the "sonic signature" of a stream or station. Songs that are bass-shy (think 70's rock) receive a boost in the lower frequencies. Songs that are overly bright (think synth-heavy 80's pop) get their top-end smoothed out.

• Band Energy (B1 – B5): The primary method of achieving a particular frequency balance of the Multiband AGCs. Higher settings result in higher output levels from that band.

• Per-Band Compression Boost: Available by expanding the "More" menu, these controls adjust the drive and activity of the Multiband AGCs on a per-band basis.

Forza's controls can be roughly divided into six sections:

• Texture: High-level "smart controls" that alter overall density and texture by adjusting multiple background parameters with a single knob or slider.

• Wideband AGC: Adjusts the drive, density, and speed of the Wideband AGC.

• Multiband AGC: Adjusts the density and spectral balance of the Multiband AGCs.

• Bass: Contains the controls to adjust the amount of texture of the bass, including bass enhancement tools and bass clipper drive.

• Multiband Limiter: Adjusts the density and spectral balance of the Multiband Limiters.

• Final: Contains the controls pertaining to the output lowpass filter, Sensus® codec conditioning, final drive level, and ITU-R BS.1770 loudness leveler.

A full explanation of the controls in each section follows.

The Multiband Limiter section has two primary functions.

The first is to control audio peaks and transients in individual parts of the audio spectrum.

The second is to provide additional density and define the texture of the processed audio.

• Density: Intelligently adjusts multiple parameters including the Drive and Threshold of all bands of the Multiband Limiter.

  • Higher settings increase the overall activity and density while maintaining approximately the same level of perceived loudness.

• Spectral Tradeoff: Depending upon the nature of the program material (and of course various settings) traditional multiband limiters can significantly alter the "EQ curve" created by the multiband AGCs that precede them in an effort to produce additional density or better control peaks and transients to keep from over-working any downstream processing stages. Forza's multiband limiters can operate in this fashion, but also offer the ability to apply a varying degree of spectral correction to bring the balance more in line with what has been created in the multiband AGCs. The Spectral Tradeoff control adjusts how much spectral re-alignment occurs.

  • Moving the control to the right mimics the behavior of a traditional multiband limiter, allowing more overall spectral variation to achieve increased density and a cleaner sound but with more potential to change the frequency balance set by the Multiband AGCs.

  • Moving the control to the left reduces the amount of allowable spectral variation and better preserves the balance set by the Multiband AGCs but at the expense of density or cleanliness with some program material.

• Per-Band Density: Available by expanding the "More" menu, these controls adjust the Drive and Threshold of the Multiband Limiters on a per-band basis.

The Final menu contains the controls that manage Forza's final processing stages and output level.

• Bandwidth: Sets the cutoff of the output lowpass filter. Streaming audio typically relies upon the use of lossy codecs that discard bits of data in order to reduce the required bandwidth. The effects of such data compression, especially when using less capable codecs and lower bitrates, can become audible in the higher frequencies. Adjusting the Bandwidth control to filter out frequencies above a certain threshold can help minimize such artifacts, though at the expense of dulling the sound.

• Sensus Conditioning: Sets the frequency range of the dynamic conditioning applied to the audio to help mitigate audible coding artifacts, much like the "Sensus Frequency" control in the Omnia.11 processor.

  • Higher settings increase the available range to include lower frequencies, allowing the algorithm to react to more of the audio spectrum.

  • Lower settings decrease the range, allowing the algorithm to work on a narrower portion of the audio spectrum more limited to higher frequencies.

  • Setting this control to "0" disables codec conditioning altogether.

• LUFS Target: Sets the desired loudness target for the ITU-R BS.1770 LUFS/LKFS loudness controller. The main Forza algorithm provides very consistent output levels, but variations in the energy and texture of the source material can still cause variations in excess of what is tolerable on a particular streaming platform or service. The loudness leveler measures and adjusts the output level to ensure a consistent "set and forget" long-term loudness target.

• Peak Target: Sets the highest allowable peak value to prevent overshoots which can cause distortion at the output of Forza or at the input to downstream encoders.

• Final Drive: Adjusts the drive to the Bass Clipper and the Final Limiter.

  • Higher settings will result in increased loudness and density, but care must be taken when making adjustments here since the affected parameters are at the very end of the processing path.

The controls in this section are used to tune the level and texture of the bass.

The rule of "a little goes a long way" applies here, so make small adjustments and listen carefully over time using a variety of source material and a variety of speakers. Consider how your target audience will listen to your content. Boosting very low frequencies may sound good on higher-end home and car stereos, but tablets, mobile phones, and smart speakers are often incapable of reproducing these frequencies.

Bear in mind that changes to these controls can affect downstream processing stages and introduce audible artifacts in higher frequency ranges if not adjusted properly.

• Deep Bass: Applies a static boost to the lowest bass frequencies.

• Girth Bass: Adds subtle low-mid to upper-bass detail. The effect is program-dependent and is similar to the "Phat Bass" control found in other Omnia processors.

• Warm Bass: Applies a static boost to mid and upper bass frequencies.

• Bass Texture: Determines how much bass peak control is performed by the first band of the multiband limiters vs. the bass clipper. Settings toward "MB" will result in more bass limiting and a softer texture, while settings toward "Clip" will allow more peaks through to the bass clipper for more "slam" on low-frequency transients.

• Bass Clipper Drive: Adjusts the drive to the Bass Clipper. Higher settings can add "punch" and "slam" to the bass, but too-high settings can introduce audible distortion on some material.

Source input audio levels are often very inconsistent. Songs may have been imported into an automation system at different levels over the years. Modern music is mastered at much higher levels than material from 20 or 30 years ago. Live sports and talk formats are a challenge to mix well due to multiple microphones and phone calls.

The Wideband AGC automatically compensates for those variations and also keeps the levels in downstream processing stages consistent. It is often described as a "slow hand on the fader."

• Drive: Adjusts the gain to the input of the Wideband AGC. More drive results in more gain reduction which in turn allows low-level audio to be increased more. Adjust the Drive control so that the average program material puts the Wideband AGC meters around 0 (mid-scale).

• Normalization Power: Simultaneously adjusts the Ratio and Threshold of the Wideband AGC. Higher settings provide more source-to-source consistency and more overall Wideband AGC activity.

• Speed: Simultaneously adjusts the Wideband AGC Attack and Release rates. Higher settings will more quickly and aggressively attenuate high-level audio and boost low-level audio, but settings that are too fast can cause audible "pumping."

Forza features three powerful high-level controls that offer a quick way to alter the overall processing texture and density by changing multiple parameters in the background with a single adjustment: Thrust, Activity Balance, and Limiting Balance.

• Thrust: Adjusting the Thrust control is the easiest way to achieve more or less overall processing without having to adjust individual settings.

  • Thrust affects Multiband AGC drive, Multiband Limiter drive, the Bass Clipper, and the Final Limiter.

  • Small adjustments to the Thrust control will have more of an effect on the Multiband AGCs, while larger adjustments yield more changes in the Multiband Limiters.

• Activity Balance: The Activity Balance slider controls the amount of processing taking place in the Multiband AGC section compared to the Multiband Limiters.

  • Sliding the control toward "Compression" works the Multiband AGCs harder in comparison to the Multiband Limiters. Sonically, this tends to provide a more homogenized and compressed sound overall while allowing peaks and transients (such as the attack of a snare drum) to pass through. This can help create a more dynamic and "punchy" sound, especially with "peaky" material (think of well-recorded music such as Steely Dan).

  • Sliding the control toward "Limiting" relaxes the multiband AGCs and transfers more of the heavy lifting to the Multiband Limiters. This approach can make music sound less "squashed" and compressed overall but at the expense of attenuating transients.

• Limiting Balance: Though the Multiband Limiters and Final Limiter are designed to work together, adjusting the balance between them can have a very audible effect on the texture of the processing.

  • Sliding the control toward "MB" relies more on the Multiband Limiters. This approach ensures that high peaks in one band won't affect the audio outside of that particular frequency range, but can cause unwanted density or spectral compromise in the Multiband Limiter section.

  • Sliding the control more toward "Final" relaxes the Multiband Limiters and drives the Final Limiter harder. This avoids building up too much multiband density and the "busy" sound that can result, but controlling peaks in one frequency range can sometimes cause audible artifacts elsewhere in the spectrum. Driving the final limiter too hard can also flatten transients to the point of making music with a high peak-to-average ratio sound lifeless, so adjust with care.