Specifications

Drawmer - MX50 Manual http://www.drawmer.com/opmx50.htm
2 of 6 1/31/2005 2:44 PM
because it contains large variations in signal level and tonal structure. Level
variations usually require the services of a compressor, which when properly set,
keeps the signal levels within a manageable range. Equalisation is also applied to
the signal before or after compression, to compensate for individual styles of voice
and also help to add prominence to the signal. For example a person with a soft,
mellow voice would probably need both low and high frequencies to be boosted to
add body and definition. Unfortunately, in many cases, although the signal sounds
just right, sibilants sounds (S's and T's) cause overload due to the EQ which was
applied. If some sort of compromise is to be avoided, some form of De-essing is
the best solution. This can take the form of equalisation applied to the side-chain of
a compressor, so that the compressor reduces the overall signal level in response
to high frequency signals only. Although reasonable results can be obtained in this
way, a dedicated De-esser is the best solution.
In its basic form, a De-esser is a Limiter with a fast release time which reduces the
signal level in response to a precise band of frequencies and then recovers quickly.
The upper cutoff frequency is generally 8kHz and the lower cutoff is variable from
800Hz to 8kHz. This allows the user to select the correct frequency band for the
vocal being processed. The MX50 uses this basic configuration with extra features
to give ease of control with total flexibility. It uses a floating threshold to avoid
constant adjustment, so the amount of De-essing is set via a single control and is
independent of signal levels over a 60dB range.
Although De-essers are most often used with the human voice, there are other
instances where a De-esser is a valuable asset to an engineer: setting the
frequency to the resonant overtones of an acoustic guitar can help to automatically
balance the level for recording; similarly, the often too harsh crash cymbals could
be De-Middled' by suitably adjusting the frequency control.
Users in doubt of when and when not to use the MX50 De-Esser could try this old
war-time radio distortion check, using a microphone channel (with suitable gain)
patched into the MX50 input: The test goes:
" Possesses' possesses more esses than any other word possesses, except
uselessness', which possesses as many esses as possesses' possesses."
CONTENTS
INSTALLATION
The MX50 is designed for standard 19" rack mounting and occupies 1U of rack
space. Avoid mounting the unit directly above power amplifiers or power supplies
that radiate significant amounts of heat. Always connect the mains earth to the unit.
Use fibre or plastic washers to prevent the front panel becoming marked by the
mounting bolts.
AUDIO CONNECTIONS
Input and Output connections are provided for use at +4dBu via balanced XLRs or
at -10dBu via unbalanced jacks. It is permissible to use both +4dBu and -10dBu
outputs simultaneously. If unbalanced operation at +4dBu is required, simply
connect the unused terminal to Ground inside the XLR cable plugs. This applies to
both inputs and outputs. The wiring convention for XLR being: pin 1 Ground, pin 2
Hot and pin 3 Cold. For use with unbalanced systems, the Cold pin 3 must be
grounded at both input and output XLRs.
INTERFERENCE
If the unit is to be used where it maybe exposed to high levels of disturbance such
as found close to a TV or radio transmitter, we suggest that the unit be operated
using the XLR connectors. The screens of the signal cables should be connected