SPL Frontliner Modular Recording Channel - Manual (Page 22)

22
Frontliner
Equalizer/Tube Saturation
Control Elements
LMF (low/mid filter)
The center frequency of the half-parametric low/mid filter is set with the LMF control. The
adjustable frequency range lies between 30 and 700 Hz so that this filter covers a range of
about 4.5 octaves, allowing it to be used from the deepest bass to the lower mid range. This
together with the mid/high filter ensures that the entire frequency spectrum is covered.
LMF -/+ (cut/boost LMF)
The LMF-/+ control determines the cut or boost of the LMF filter; the maximum values are +/-
12 dB. The LMF filter also operates to the proportional-Q principle, in other words the band-
width is dependent on the selected boost or cut. The LMF filter can be applied in many ways.
Examples are to accentuate the fundamental sound of a voice, to cut “boom frequencies” and
for placement of instruments such as bass guitar, bass drums or synthesizers, both during
recording or subsequently when mixing.
Recommendation on frequency settings: To find the frequency which is to be processed as
quickly and accurately as possible, firstly adjust the LMF -/+ control to the maximum posi-
tion. Subsequently the relevant frequency should be sought. Because the filter at maximum
setting works with the smallest bandwidth, the frequencies can be heard most distinctly at
this setting, making them easier to locate. Finally the desired LMF +/- setting can be applied
after the frequency is determined with LMF.
AIR BAND
The high frequency filter in the equalizer module is described as the AIR BAND. A coil/capac-
itor filter with so called bell characteristics and a center frequency of 17.5 kHz comes into
operation here. At this frequency the maximum possible accentuation is +10 dB, the maximum
possible damping is -10 dB. The soft and natural tonal characteristic of the coil-capacitor filter
lends itself extremely well to provide clarity and, well ... air to vocals in the upper frequency
range, thereby improving their presence. On the other hand harsh sounds can be lent a more
pleasant sound characteristic through damping.
TUBE SATURATION
With this control you determine the amount of tube saturation. The output level is accommo-
dated automatically, in extreme settings the level increases by only 6 dB. Therefore you can
easily dial in decent to expressive harmonic distortions with the TUBE SATURATION control by
turning just one knob.
Saturation effects are generated through the tube being pushed to and beyond its normal
operating limits. In contrast to semiconductors, a tube thus pushed to such levels does not
clip from a certain level, approaching more gradually its level limits and thereby producing
its typical tonal result, which in audio signal processing can have such often profitable aural
effects —on one hand (and depending on the amount applied), from subtle to extensive
harmonic distortion and on the other hand, a compaction of the sonic event, that is, a limiting
effect that exhibits a pleasant, rounded or soft sound. Acoustically and also in its range of
applications this can be compared very well with tape saturation effects.
LMF
30
4
0
5
0
80
125
160 200
3
00
5
00
64
0
70
0
Hz
LMF – / +
-12
-
10
-
5
-2
.5
0
2.5
5
7.5
10
12
dB
AIR BAND
-10
-8
-6
-
4
-2
0 2
4
6
8
10
dB
TU
BE
SATURATIO
N
0
1
0
2
0
3
0
4
0
50 60
7
0
80
9
0
10
0
%