7. Operational Notes
7
of the drum is diminished. If used gently, this can be
applied to brighten up the attack of the drum, but it
is difficult to apply in practice because drums can
be very dynamic.
One great use is on the room mics. The initial drum
sound is pulled down, then the natural reverb is
increased. Shades of early Led Zep. While we
mentioned that “LA” style limiters are not what we
suggest for mixes, there are times when the drums
are too loud or when the engineer can mix “into”
the limiter. Both techniques are possible, but not
necessarily easy. One trick is to just barely tickle
the GR meter. Some of our clients use the ELOP+ on
mixes as an effect. This application is valid as long
as the effect given and the effect desired are the
same.
There are not many options for adjustment and fine
tuning. The good news is that the ELOP+ is clean
enough to pass a good mix. In a live sound setting
the ELOP+ will perform as a fine speaker protection
device. Once again the Threshold is set for minimal
limiting with music and is just adjusted to
encourage the pyrotechnician to try harder
tomorrow to kill a few woofers.
The slope or ratio is also difficult to simulate. The
initial ratio is low and becomes higher with more
gain reduction until the LEDs light up fully and
further reduction is not possible.
This upper limit of reduction is in the area of 20 dB
or at the bottom of the GR meter where the ratio
becomes low again, but this would be a severe
setting that few engineers could use. Distortion
becomes audible at very deep limiting.
In a tech shop, it is easy to drive the limiter to 20
dB of reduction and beyond where the GR meter
shows a flaw in that it “folds back”. We put a higher
priority on having the meter show what the unit was
doing accurately with “normal settings” than
extreme test bench observations. Test benches don’t
make hit records.
So these types of electro-optical limiters seem to be
great for vocals, but what else are they used for?
And what about sounds where the time constants
are less than optimum?
Historically, “LA” style limiters were often used for
bass and guitar tracks. They can be ideal for brass,
saxes, synths, and similar sounds with superb
results. There are other compressors that work well
for these instruments, but few that are as
transparent. Usually, when you hear of an engineer
using another type of compressor for these
instruments, it is framed with “for the crunch” or
because they add some desired color. There are only
a very small number of “clean” general purpose
variable time compressors which seem to give “LA”
style units competition - our Variable Mu® is at the
top of that list.
Where the “LA” style limiters are not always
appropriate is for percussion and for mixes where
the percussion is just right. The cell typically reacts
fast to peaks - fast enough to remove drums from a
mix but not quite fast enough to be called “brick
wall”. Individual drums tend to have a little of the
initial transient let through, but the desirable tone
