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Additionally, the control for the HP Filter (fm Turbo style only) is located in this menu. In most FM systems,
subsonic frequencies in the input audio program should usually be rolled off to prevent difficulties with certain
exciters and STL systems. The Omnia-3fm Turbo has a third-order (18dB/Octave) high-pass filter with five
selectable cutoff frequencies from 60 Hz down to 20 Hz. The factory default is "Out", which means that audio
frequencies to well below 2Hz are passed through the system without attenuation. You may select one of the
other values that may be more appropriate for your system.
One final control is the Phase Rotator bypass. Phase Rotators (also known as Phase Scramblers) are commonly
utilized to make asymmetrical waveforms (such as voice) more symmetrical. This ensures that clipping occurs
equally on positive and negative peaks, making better use of the symmetrical nature of the modulation process.
Phase rotation can make talent voice sound cleaner, but since it disturbs the phase integrity of musical signals,
music might sound more faithful to the original source if phase rotation is not used. Off can be chosen if
previous phase rotation has been performed in your system (in a microphone processor for example) or to
preserve the phase integrity of the original program as described above.
Bass & Warmth Enhancement
Deep Bass EQ: For those who demand thunderous bass, the Omnia-3 has it! Up to 12 dB of "thunder" can be
added to shake your listener's walls! This is not a simple bass boost, but a rather sophisticated concept that
takes into consideration the time alignment of the low frequencies as they pass through the entire Omnia
system. It allows a loud, clean low end, with absolutely no sacrifice to the overall loudness of your signal. We
won't tell you where the control is in the signal chain. But we will tell you that Deep Bass function is a shelf
boost at 90 Hz, utilizing a phase compensated 12dB/octave slope to emulate the EQ function.
Phat Bass EQ: Phat Bass is a unique enhancement that adds filtered harmonics of the lower registers to the
upper bass frequencies. The algorithm extracts information contained in the initial attack to do its work, and low
frequency texture is therefore emphasized. Older recordings sound fuller (or phatter) with the added illusion of
loudness. Phat Bass EQ also helps radios with small speakers sound like they have more bass than they actually
do. A little of this effect goes a long way so be careful not to apply too much boost. Be sure to listen on several
different types of radios to arrive at a setting that works best for all of them.
Warmth EQ: The Warm Bass parameter in the Enhance section of the Process submenu is a shelf boost at 150
Hz. This compensates for program material that is naturally lacking in upper-bass punch. Be judicious about
applying too much, as this can cause excessive gain-reduction in the low and mid bands. Also, the resonant
frequency of most automobile interiors lies in this frequency range!
XOver
The crossover points are set in software and cannot be modified. In fm Turbo units, they are set at 150 Hz and 3
kHz. In Omnia-3fm Turbo units, the 3-Band AGC's and Limiters are in series and share the same crossover. In
am units, the 4-Band Limiter crossover points are 150 Hz, 750 Hz and 3 kHz. You can however, change the
output gain of each crossover filter using the LF Drive, MF Drive and HF Drive controls. These control the
drive level of the audio fed to the following respective multiband section. These are some of the key
adjustments you will be using to increase loudness! The greater the drive, the greater the loudness and the effect
of dynamic equalization to achieve a consistent spectral balance. Increasing some bands while not others
effectively adds emphasis to those boosted bands.
HF EQ: (Omnia-3am only) This parameter adds the high-frequency boost that conforms to the NRSC emphasis
recommendation for AM broadcasting. Increasing HF Eq will add boost to the presence and treble range that
follows a high frequency shelf network that is inserted before the multiband limiter section. Typical settings are
from about 10 to 14.
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