Ease of Use: 4
Single Mastering Unit
The MixMaster is an analog stereo audio processor designed for mastering
applications in project and home studios. The review unit we received came
with the optional 24-bit and up to 96kHz analog-to-digital converter for
direct digital connection to a DAT or CD recorder. While the MixMaster is
made specifically for mastering stereo mixes, it is useful any time you
want to maximize the level and "punch" of single- or two-channel audio.
MixMaster's complete tool set contains all you'll ever need for this task
and will free up other analog or digital processors you may have
Read Barry's Mix Magazine Compressors and Compression Feature.
The two-rackspace unit has both balanced XLR and unbalanced 1/4" input and
output connections on the rear panel as well as direct inputs for mixing
external audio sources with the output signal. There is extensive LED
metering: a single meter that reads both input and output levels (although
there is no indication of which is being metered, so pay attention to
whether the button is set for "in" or "out"); separate gain reduction
indicators for the stereo expander, spectral compressor and peak limiter;
stereo phase and separate overload indicators for the compressor and
equalizer processor sections. All of this metering makes for quite a light
show when the unit is hard at work.
A block diagram in the wonderfully written user's manual shows that the
MixMaster has five stereo processors or sections: Stereo Expander,
Spectral Compressor, Stereo Parametric Equalizer, Image Width processor,
and Peak Limiter. The order of the processors shown in the diagram is
consistent with the front panel layout of controls. There is no way to
"re-order" the chain of processors, and in actual use, I found little
reason to require it. For each processor there is a lighted, hardwired
bypass switch, and a global bypass button takes the entire unit out of
circuit. Note that setting up a processor requires the respective section
to be engaged for the LED meters to read. I find this unfortunate,
especially for live sound work where I would like to get a ballpark
setting beforehand (using active meters) and then switch in the section on
the fly to fine tune.
Both +4dBu and -10dBu levels can be used with the MixMaster, making it the
perfect "bridge" between semi-pro gear, such as your small mixing board,
and fully professional gear such as analog 2-track machines or digital DAT
machines. There are no switches to set; just plug whatever you have into
the back panel and go.
The expander section is first in the chain because it operates much like a
very soft noise gate, shutting down and cutting off any signal below the
front panel's threshold setting. Called "downward expansion," it is useful
for noisy analog tapes or residual noises because it works all the way
down to the noise floor. I liked this feature for killing sound like amp
buzz, noisy effect returns and the room tone audible right before the
opening downbeat of a song. There is a Release time control which I set to
the maximum of six seconds so that the expander stayed open throughout the
song once it started (assuming there'd be no gap in the music longer than
Stereo Spectral Compressor
The Spectral Compressor section is worth the entire price of the unit. The
Spectral Compressor is an optocoupler design with three independent
frequency bands. You can also operate this section as a standard, full
bandwidth stereo compressor when you use the Lock button. In fact, that's
the way I first tried the compressor to evaluate its sound quality when I
compressed a stereo piano track. This section is especially well suited
for program material, and my piano sounded great through it.
There is a global Threshold control for setting compression amount just
like any other compressor, but there are also both LF (low frequency) and
HF (high frequency) band Trim controls that allow 20dB relative variation
in the threshold for these two bands. It's great to be able to compress
more in certain frequency ranges than others! For example, you can
compress less in the high frequencies for a more open high-end sound. By
only compressing low frequencies, a loud kick drum can have all the punch
it needs without causing the rest of the mix to pump.
The Ratio control adjusts compression ratios from a smooth 1.3:1 all the
way to 1:5. Release time is adjustable in steps: 0.2, 0.4, 0.8, and 1.6
seconds. There are also PDF and PDS settings for Program Dependent Fast
and Program Dependent Slow. I recommend using one of these settings when
you are not certain about fixing the release time. These ranges and
settings are all great for programming dynamic control of your mixes.
There are two choices for attack time with the Slow Attack button giving
you the choice of a little slower attack time when the default faster attack seems to make the compressor grab too often and quickly.
The LF Slope button changes the crossover frequency between the LF and MF
bands. The default crossover point is 200Hz, and pressing the button moves
it down to 100Hz with an added emphasis. This is said to be good
especially for dance music processing. Finally, Make Up Gain adds level
back to compensate for gain reduction in the compressor.
The equalizer is a three-band type with stepped frequency selection for
recall of settings. The boost and attenuation control is also a stepped
switch for repeatability. Being able to reset the MixMaster is important
in mastering since you will want to return to particular settings (for
further tweaking) after checking your mixes on other stereo systems.
The LF section is a shelving filter with 40, 70 and 120Hz positions and a
Tilt position that changes it over to a 2dB per octave filter starting at
1kHz--good for a general bass lift (or roll-off). The HF section is also a
shelving filter, with 10, 14 and 20kHz positions. Here, Tilt positions
turn the processor into a kinder, more gentler treble equalizer. Midrange
is handled by a parametric equalizer with a very wide frequency range of
100Hz to 10kHz. The quality of the filter, or Q, ranges from a broad 0.4
to a more narrow 1.5.
Spectral Enhancer/Direct Input/Peak Limiter/Output
The Spectral Enhancer is part of the Output section. The Balance control
will correct something I obsess over: stereo imbalance, where one side is
louder than the other. The range is + or - 3dB. However, this control is
only active when the Image In switch is in. Width controls the level of
L+R signals and the L-R signals that make up all stereo recordings.
Essentially, all center or monaural information is the sum of the left
channel (L) and the right channel (R), called the L+R component. All
difference information such as reverb, delays, room sounds or other
out-of-phase signals comes under the the L-R component.
The Width control has a center-detented Normal position for regular stereo
width or image, depending on the stereo width you already have. Rotating
the Width control to the left lowers the level of the L-R component,
decreasing the stereo width; rotating to the right increases the L-R for
an extra wide stereo sound. I used this processor on a mix I thought
lacked sufficient stereo size, using the on-board phase meter to monitor
the results. I would use this feature conservatively if your mix will be
converted to mono or cut to vinyl because it compromises mono capability.
The Direct Input feature allows for external +4dB signals to be mixed into
the final output before the Peak Limiter and after the
aforementioned Image section. This is an interesting feature. A good use
for it is mixing a vocal (with its own processing) into a backing track
coming through the MixMaster.
The Peak Limiter operates at a fixed threshold matched to the input of the
optional analog-to-digital converter output. This limiter will absolutely
prevent you from overloading the digital output. Finally, the Output Trim
control sets the final level coming out of the MixMaster.
The Platinum Focusrite MixMaster is a great new analog tool for project and
home studios where better control of stereo audio is required for master
recordings. Available through Digidesign, MixMaster has an MSRP of $1,395
and the optional 24-bit/96 kHz A/D board retails for $350. You can
purchase MixMaster with the A/D board installed from the factory for
Check out: www.digidesign.com
or www.focusrite.com for more information.