State of inputs...

Sound4FM2 has three inputs (Digital, Analog and PCI).
 
The triangle present on the left side of the inputs indicates the input currently use (here it is the Digital input that is used as the first backup, since there is no longer any modulation on the principal Analog input).

Wide Band AGC...

In Sound4FM2, the first processing function is the “Wide Band AGC”: it is an automatic gain control operating in broad band. Its main purpose is to “level out” gaps of levels applied at the level of the processor.
 
The algorithm specially developed for this AGC is of the predictive type. It authorises very high sound variations without any sort of pumping. Compared with other processors, the facility of control of the input gain is incomparable. 

The Tone FX...

The “Tone FX” makes colouring of sound possible before dynamic processing. To do so, it groups together two types of processing functions:

 

• A 4-band parametric equaliser;

 

• An effect system making it possible to strengthen low frequencies and high frequencies.

The two functions offer results that are entirely different, which is why they are gathered on one single screen.
In “Easy”, use of the four parametric equalisers is simplified to the maximum. Only the gain for each correction is accessible. For “FX Bass” and “FX Treble”, there also only dosing of the effect is made accessible.
 
In “Full” mode, you have access to all of the parameters of the parametric equaliser (gain, frequency and Q factor). 

The Stereo FX...

Sound4FM2 has a true stereo enlarger, 100% mono compatible. Its role is to sublimate the existing stereo image. It will thus never create stereo on mono sources.
 
In addition to embellishing the stereo image, it has a stereo image limiter acting on the control of the energy transmitted by the stereo sub-porter at 38 kHz. This unique functionality thus limits annoyances currently occasioned by the traditional enlargement processes. The stability of reception in areas disturbed by multiple routes is thus very greatly optimised.

The "2-Band Process"...

The “2-band Process” is the heart of the dynamic processing of Sound4FM2. A single algorithm guarantees the gain in each of the bands in order to complete sound stabilisation. “Colouring” is controlled by the Fidelity parameter: thus, it is possible to have a purist and coloured sound texture.
 
The “2-band Process” is provided wit the revolutionary algorithm S.I.S (Sound Impact System), which makes it possible to maintain the authenticity of the original sound attacks.
 
The “2-band Process” is extremely powerful, which is why it is not always necessary to make the input AGC operate, it being capable all alone of absorbing very high variations of sound.

The "2-Band Limiter"...

The first purpose of the “2-band Limiter” is to prepare the work of the final limiter. It is also provided with a very powerful predictive algorithm, which has been simplified to the maximum in order not to be encumbered with useless parameters.

The "Final Limiter"...

The “Final Limiter” groups together three limiters:

 

• The “HF Limiter” for controlling energy in the high frequencies. It has an adjustable Drive which makes it possible to improve perception in the high frequencies.

 

• The “HD Limiter”, specially designed for high-quality digital applications (HD / DAB / DRM), involving a limiter of the Look-Ahead type. Its delay time is also adjustable. In this mode, outlets are not limited to 15kHz.

 

• The “FM Limiter”, intended for FM applications. This is an extremely powerful clipper operating at a sampling frequency never achieved: 1.5 MHz!
  

Assignment of outlets

the outlets of Sound4FM2 are fully assignable. Here the analog outlet replicates the signal which is applied on the analog input, the digital outlet delivers an HD signal, the TX1 outlet delivers the MPX signal and the TX2 outlet the 19kHz pilot signal.