OPTIMOD-PC
OPERATION
3-55
setting, you can sometimes ameliorate or eliminate the pumping by slow-
ing down the compressor attack time in that band.
K)
Adjust the
T
HRESHOLD
controls in the individual bands to achieve the desired
amount of gain reduction.
This is the most effective way to set the spectral balance of the process-
ing when the compressor is exhibiting gain reduction.
L)
Adjust equalization as necessary.
As discussed above, there a multiband equalizer available between the
AGC and multiband compressor. In five-band mode, there is also a five-
band mix control (functioning as a graphic equalizer) after the five-band
compressor and a threshold control for each band compressor. In five-
band mode, any fixed equalization will be partially “undone” by the dy-
namic re-equalization effect of the five-band compression, so two-band
mode is most useful when you are relying on OPTIMOD-PC’s fixed EQ or
on external EQ earlier in the signal path.
Note also that you can use the individual band compression threshold
controls, the
B
ASS
C
OUPLING
control, and HF
C
OUPLING
control to affect
the amount of automatic re-equalization performed by the five-band
compression. As you set these controls closer to 100%, they permit pro-
gressively less dynamic LF and HF program-adaptive boost. If you feel
that the dynamic re-equalization is not producing enough brightness
when the program material lacks high frequencies, you should turn the
B
AND
3>4
and
B
AND
4>5
C
OUPLING
closer to 0%. Similarly, if weak bass is
not sufficiently boosted, turn the
B
AND
2>1
C
OUPLING
closer to 0%.
M)
Set the amount of peak limiting with the
F
INAL
L
IMIT
control.
In general, the less peak limiting you use, the better sounding the result
will be. However, if your client demands a “loud” CD, OPTIMOD-PC’s
look-ahead peak limiter is a powerful tool for achieving this with mini-
mum distortion or other side effects. Nevertheless, be aware that this
function is not like some familiar “look-ahead” limiters. The release time
is in the order of a few milliseconds and is not user adjustable. The pur-
pose of the limiter is
only
to limit peaks that pass through the earlier
compressors because of their finite attack times. Functionally it is used
like a peak clipper, but it has vastly reduced modulation distortion by
comparison to a clipper, whether “soft knee” or “hard knee.”
The main potential side effects of the look-ahead limiter are gain breath-
ing and a “warbling” sound in the midrange when heavy bass is simulta-
neously present. Listen carefully for this intermodulation effect (particu-
larly on vocals) when you are adjusting the
F
INAL
L
IMIT
control.
N)
Adjust the
B
ASS
C
LIP
control to complement the amount of final limiting.
For most mastering applications, you can set it to Off. Which defeats it.
However, if you hear pumping or distortion in the look-ahead limiter
caused by heavy bass transients, you can reduce this effect by setting the
B
ASS
C
LIP
to a lower level. (The
B
ASS
C
LIP
control is calibrated in “dB be-
low the final limiter threshold.”)
O)
If you want to compare your processed sound to the unprocessed original, re-
call the
B
YPASS
preset and toggle between it and your processing preset. If
