Lexicon 480L | PDF - Freeverb3
Lexicon 480L | PDF - Freeverb3
Lexicon 480L | PDF - Freeverb3
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Bank 10: the Compressor Programs<br />
ATC (Attack Time Constant)<br />
ATC adjusts the speed with which the compressor<br />
responds to an increase in input level. The nominal<br />
value is about 30ms. The times on the slider move in<br />
factors of 2, from 7ms to about 1 second. Both 7ms and<br />
15ms will cause some distortion and are not recommended<br />
unless delay through the program cannot be<br />
tolerated. High values of ATC can be used with large<br />
delays in a program-leveling application. The filter<br />
used for ATC is a non-linear filter. The number of dB/<br />
second depends on the rate at which the input is<br />
changing. Fast changes will make a quicker attack,<br />
causing the gain to decrease quickly.<br />
RTC (Release Time Constant)<br />
RTC adjusts the release time constant. This filter<br />
maintains a constant number of dBs per second, regardless<br />
of the size of the change. Thus, the rate of<br />
increase in gain is constant. The value displayed for the<br />
release time is something of an approximation, since<br />
the ordinary meaning of “time constant” does not apply<br />
to this type of control.<br />
Page Two<br />
EXS (Expand Slope)<br />
EXS adjusts the slope of the expansion. It behaves<br />
similarly to the compression ratio, but it is important to<br />
keep in mind that the expander and the compressor in<br />
this program are not in series. They both respond to the<br />
same input level, but in different ways. For example, if<br />
some material is compressed with a 2:1 ratio, recorded,<br />
and then played back through the expander<br />
with a 2:1 expansion ratio, the original dynamics will be<br />
restored. The same will occur if two compressor programs<br />
are run in cascade. However, if the compressor<br />
and expander are both set to operate in the same<br />
program at the same time with identical THR points and<br />
slopes, the result will not‘ have the original dynamics.<br />
Consider a drop in input level of 6dB. For a 2:1<br />
compression in level the output gain should increase<br />
3dB, giving a net drop in output level of 3dB. However,<br />
for a 2:1 expansion, the output gain should drop 6dB,<br />
giving a net output of -12dB. If both the compressor and<br />
expander are operated at the same time, the net result<br />
will be an output gain decrease of 3dB, representing a<br />
net expansion of the signal.<br />
EXT (Expander Threshold)<br />
EXT sets the level below which expansion starts. When<br />
the expansion is intended to apply to the whole program,<br />
or perhaps just to the peaks of the program, EXT<br />
should be set to about 10 or 12dB, similar to the setting<br />
of the THR control of the compressor. If the expander<br />
is to be used as a noise gate, EXT should be set much<br />
higher, to just below the level of the noise.<br />
EXM (Expand Maximum Attenuation)<br />
EXM sets the maximum attenuation reached by the<br />
expander. It is similar in operation to the GAIN control<br />
of the expander.<br />
Programs — BANK 10:<br />
Compressor/Expander<br />
1 2.00=1 COMP<br />
DLY SLP GAIN THR ATC RTC<br />
27.45ms 2.00=1 9dB 21dB 15ms 91ms<br />
EXS EXG EXT<br />
2.00=1 10dB -48dB<br />
2 6.24=1<br />
DLY SLP GAIN THR ATC RTC<br />
12.56ms 6.24=1 12dB 16dB 7ms 91ms<br />
EXS EXG EXT<br />
1.88=1 7dB -40dB<br />
3 18.28=1 COMP<br />
DLY SLP GAIN THR ATC RTC<br />
20.38ms 18.28=1 10dB 20dB 15ms 91ms<br />
EXS EXG EXT<br />
2.00=1 10dB -48dB<br />
4 Transfer<br />
DLY SLP GAIN THR ATC RTC<br />
40.26ms 1.33=1 10dB 10dB 30ms 73ms<br />
EXS EXG EXT<br />
1.00=1 0dB 0dB<br />
5 Vox Easy<br />
DLY SLP GAIN THR ATC RTC<br />
12.56ms 5.00=1 8dB 15dB 7ms 73ms<br />
EXS EXG EXT<br />
1.88=1 7dB -40dB<br />
9-3