Mix On the Run
For those occasions
when the audio has to shine and the two channels on your camera just aren't
enough, enter the DV Promix 3 by Professional Sound Corp, a sleek little audio
mixer that's built like a rock and packed with the tools necessary to produce
studio quality recordings in the field.
First Things
First
The DV Promix 3 is a 3-XLR-in, 2-XLR-out mixer that can handle just about any
audio source including line level signals, dynamic (non-powered) microphone
signals and even professional quality, phantom-powered condenser microphones.
Selector switches for the line type settings are located on the left panel next
to each of the three XLR input connectors. The front panel features three rotary
level controls, each with a dedicated left-center-right pan switch and
3-position low-cut filter switch for wind noise reduction. Continuing left to
right, there's the LED level meters and headphone volume control followed by a
monitor switch, tone generator on/off switch and an internal/external power
switch. Moving around to the right panel we find the two XLR outputs, each with
a line/mic selector switch and, finally, three 3.5mm outputs -- one each for
headphones, tape return and mic out. Around the back are two slide-out doors for
the 9-volt batteries that power the unit and an external DC power input.
Blinded by the
light
The first thing you notice when you switch the unit on is the twenty super
bright LEDs that make up the level meter. They all flash on at power-up and,
designed to be visible in bright daylight conditions, are absolutely blinding in
a dimly lit edit bay. Once the retinal burn fades, you see that the Promix 3 is
ruggedly built from .040" aircraft aluminum and the rotary controls have a
smooth, high-quality feel similar to those found on Mackie studio mixers. With
the included protective carrying bag and shoulder strap, the whole package
weighs in at a light 1lb. 11oz.
Before heading
outside, We plugged in a Shure KSM-44, a large diaphragm condenser microphone
known for its warm, rich voice reproduction. Listening to our favorite
voice-over woman through Sennheiser HD202s plugged directly into the Promix 3's
headphone jack, everything was clean and smooth. Just like our 36-channel studio
Mackie mixer.
Out Standing in
the Field
To put the Promix through its paces in the great outdoors, we loaded up a couple
of our studio crew members, and several Samson UHF Series One wireless kits with
Sony ECM-44 lavaliere mics, and drove out to our favorite little league field
where we knew we could count on blustery wind conditions. Already knowing that
the mixer passed clean sound, we were interested in testing the low-cut filters'
wind-noise suppression abilities. There are 3 settings on each of the three
input channels low-cut filters: 20Hz for windless days, 80Hz for low wind
conditions and 150Hz for recording in high winds.
Winds were light
this day -- probably 10-15 mph. Our crew spread out with their mics, holding
them up like kite strings to intentionally catch some wind. The 150Hz setting
did a great job of knocking down the wind noise when we were moving the mic in
the air and eliminated it completely when the lavalieres were clipped to shirt
fronts as they would be on a real shoot. The sound remained good and we couldn't
detect any significant loss in headroom..
So, once again, the
mixer did what it was supposed to do. And remember that super-bright LED level
meter? Even in direct sunlight, it's incredibly easy to read.
One feature that's
invisible until you need it is the limiter circuit built in to the Promix 3. Set
at a 2.7 to 1 reduction ratio, this feature compresses output spikes to reduce
over-modulation in the signal going to your camera.
Another feature we
found especially convenient was the tape return jack located on the output
panel. Running a cable from this output back to the camera mic input allowed for
confidence monitoring through the camera's headphone jack.
Is 3 better than
2?
As good as the Promix 3 is, what occurred to us while we were putting it through
its paces in the field, is that most of its features, balanced-in/out, channel
pan, low-cut filtering, etc., duplicate what's already on most prosumer DV
cameras. The difference is three channels over two. Given the Promix 3's $495
price point, you really have to ask yourself if that one extra channel is worth
it. Over the years, I've found that when I had a shoot where more than two
channels of audio were required, it usually meant that I was going to need a lot
more, not just one more. PSC knows this, we think, because they'll be shipping
the Promix 6 by the time you read this.
Who Needs It?
Having given the Promix 3 all the kudos it deserves, we're not sure who is
actually going to absolutely, positively have to have it in their field
equipment arsenal. If you're shooting with any of the many DV cameras with
balance inputs you're probably not going to be able justify spending almost
five-hundred bucks for one additional channel of mixing capability. However, if
(1) you're shooting with a camera that doesn't have balanced I/O and (2) you
need to field mix three audio channels and (3) you can afford to spend $495, the
Promix 3 by Professional Sound Corp. won't let you down.
TECH SPECS
Size: 9.950" X 6.675" X 1.500" (25 cm X 17 cm X 3.8 cm)
Weight: 1 lb., 11.5 oz (0.8 kg)
Distortion: 0.08% THD @ 1kHz
Power: 2x 9V Alkaline Batteries, 4 to 6 hours typical run time or external power
of 7 to 18Vdc
Inputs: XLR Female, Electronically Balanced, 3K Ohm Impedance,3-Way Switchable,
Line Level, Dynamic Mic, Condenser Mic
Mic Power: 48PH to DIN Specifications, individually switch able
Low Cut Filters: 6dB/Octave, -3dB at 80Hz, -3dB at 150Hz
Channel Pans: Individually Switch able Left, Center, Right
Frequency Response: 20Hz to 20kHz +/-0.5dB
Noise Level: -128dB EIN, 150 Ohms, "A" Weighted
Tape/Direct: Headphone Monitoring, Direct (mixer) or Tape (camera)
Limiters: Outputs, approximate 2.7 to 1 ratio above threshold
Meters: LED, Peak Reading, Sun Light Readable, -20dB to +3dB
Monitor Volume: Rotary Control, Off to Maximum Volume
Outputs: XLR male, Balanced, Line (0dBv) or Mic Level (-50dBv)
Auxiliary Outputs: 3.5mm Jack, Dedicated Microphone Level Output (-50dBv)
Headphone Out: 3.5mm Jack, will drive 25 to 600 Ohm Headphones
Warranty: One year limited
STRENGTHS
-
Balanced XLR
microphone input/output connectors
-
Phantom power
switchable on each input channel
-
Low Frequency
roll off filters on each input to reduce wind noise
-
Dedicated
Microphone level output jack for use with cameras not equipped with XLRs
WEAKNESSES
SUMMARY
A solid well designed mixer for those needing a third mic or line input or need
to remove the mixing controls from the camera body.
Richard Gray is
the Production Manager for a network affiliate TV station.
