there. I work deep in the bowels of Gotham Sound’s rental department. From time
to time I mix freelance on the weekend, usually for folks on a low budget, and
usually into a video camera. I had a job like this over this last weekend. Just
for kicks, I brought the Zaxcom stereo wireless with me. People rarely seem to
rent the thing, so it is usually available – and I’d been curious. This article
is about my experience using it as a wireless hop to camera. I didn’t use the
recording feature at all, and cannot comment about it whatsoever.
My setup was: A MixPre, a channel of Lectrosonics Block 22, a 416 and the
Zaxcom TRX900 Wireless Transmitter. I brought along a straddle bag to mount
the receiver to the camera, but the camera (a JVC something) ended up being too
small to accommodate it. The cameraman ended up tying the bag to his belt –
which seemed to work out fine for him. He also agreed to put a pair of
headphones on – a lucky break for me.
Setting my gain structure with this setup was easy due to the transmitter’s
comparatively articulate metering. Getting identical levels for both channels
was a cinch. Structuring the gain of two channels of Lectrosonics is a kind of
voodoo: you’ve only got two LED’s that can show two different colors each –
meaning that the meter has five bits of resolution with which to describe your
audio’s dynamic range. You’ve also got some metering on the receiver, too – but
frankly I trust that as much as I trust its “scan” function. Most of the folks I
talk to get the tone from their mixer metering at 0dBu, and tweak the gain
rotary knob on the TX until one or both LED’s shines green. Nobody I talk to
says: “I tweak the knob until the first LED is solid and the other is faintly
By comparison, levels on the TRX 900 are described by two vertical lines that
move across the length of its LCD screen, and gain is set via two inset
screwdriver pots on the stereo adapter. The meter proved extremely sensitive to
even slight tweakage. I found this metering to be way more descriptive and
therefore useful. That said, it was still far from empirical metering: I still
don’t know for sure what information that meter was giving me. There is some
metering on the receiver, but unfortunately it seemed Lectro-inspired – even
more disappointingly it appeared to contradict what I was reading on the
transmitter, in that the receiver indicated clipping before the transmitter did.
On this and other subjects the TRX manual is ambiguous. I proceeded with the
assumption that I was metering dBFS.
What assisted me further was the fact that you can sort of monitor the
transmitter itself in a perfunctory kind of way using the 1/8” Audio/TC output
on the stereo adapter. I found that when I connected this to my mixer’s return,
I heard whatever I was sending to the TX’s right channel in both headphones,
after the TX’s input stage. This didn’t and still doesn’t make sense to me (why
right only?) and referencing the manual explained next to nothing. “The audio
output connection is used to monitor the audio functions of its host unit or to
allow time code to pass through the STA100. The mode on the host unit determines
if audio or time code is sent through output.” Gently put, this statement is
misleading. I could find no such mode.
In any event, it was easy to hear when I was clipping the transmitter. I set the
MixPre’s “0dBu” to roughly 1/3 of the TRX’s dynamic range, and then I adjusted
the video camera’s gain until I metered there at –20dBFS. My intent was to
create a situation in which I would clip the mixer’s output before I clipped the
transmitter’s input, and to ensure that the transmitter’s clipping point
measured slightly less that 0dBFS at the camera. The TRX900’s stereo adapter has
no input limiter, and when it clips it does so in a fatal, intolerable way.
Because of this it would be smart to use a mixer featuring an output limiter
like the Sound Devices 302 or 442.
So I set up what I felt to be a pretty foolproof gain structure, the
cameraman has his headphones on, and we began to shoot. After the first
interview, I walk over to camera and ask if I can hear some playback. Simply
put, it didn’t sound wireless. It definitely wasn’t exactly what I’d heard at
the MixPre’s headphone amp during the shot, but it didn’t sound like wireless.
I’m willing to imagine that a wired connection would have sounded better – but
the point seems academic to me, as I am sure that this is as much fidelity as I
will ever need on a video camera.
It must be said that my conditions were extremely favorable: I was never
further than 15’ away from the camera, and we were in a park in southern New
Jersey, far from any serious urban area.
I’ve set up dozens of reality TV packages for Gotham’s customers. I’ve become
very familiar with the sound of a TR-50 being stepped on by two gain stages of
Lectrosonics wireless. The audible result at the last stage is acceptable
because it is a compromise on behalf of necessity, not because it sounds any
good. The Zaxcom hop represents an incredible step forward in convenience
without perceptible loss in quality.
The shoot went flawlessly. Early on, the producer would ask for playback
during every break in shooting. She’d never heard of “Zaxcom”, and I think that
the setup made her nervous. After the third time, the cameraman promised her
that it was unnecessary. He was deeply impressed with the sound quality.
Finally, there is at least one videographer out there that thinks I’m awesome.
It occurred to me that the people who are going to love this product the most
are the camera operators, who will be free now to indulge in their weirdest,
most unpredictable physical impulses without worrying about the audio tether.
Range was never an issue for me, nor did the Zaxcom transmitter’s proximity
to my Lectro receiver appreciably affect the Lectro’s performance. The only time
I was able to create an interaction between the two was under the following
conditions: Lectro channel powered ON with the lav unplugged and the TRX’s
antenna physically meeting with the UCR411’s, with the MixPre’s gain potted all
the way up as well as the headphones’. At the shop at Gotham, I left the TRX
plugged into my iPod way in the rear of our office and walked out of the
building carrying the receiver and a small mixer from which to monitor. I got
halfway to 9th Ave (more than 500 feet, and through an exterior wall) before I
exceeded the range.
As perverse as it sounds, I even like the way in which the Zaxcom wireless
fails. The performance of a channel of Lectrosonics seems to be infinitely
varied. The same units will literally sound very different in different places
due to the local RF environment. In my experience the Zaxcom either sounds
perfect or it doesn’t sound at all. There is seemingly no middle ground between
total fidelity and silence – fatal-error dropouts begin to occur resulting in a
completely useless recording. Leaving aside the on-board recording option, as we
are, one is left with no option other than to break the camera snake out of its
Pelican. This is appealing to me, but I can see why folks would prefer a gentler
People will say that the TRX’s interface is too obtuse to understand. I agree
with them completely. All the same, I’m putting the public on notice: if you’re
unable to operate the TRX’s basic function of accomplishing a stereo link
between mixer and camera, chances are you can’t use a computer, either. If
you’re reading this, you are perfectly capable of using a TRX.
Why aren’t more people using these things? When you consider that a channel
of Zaxcom stereo costs less than two channels of Lectro 411, you’d think that
these things would have long since taken over the industry if only as a
convenient but expensive replacement for the breakaway cable. It has been
available now for a whole year. Nevertheless, at least in New York, the reality
industry and ENG crews have continued to neglect it. Here is a product that
outperforms its competitors not only in performance but also in price. From my
perspective as a lower-level monkey at a sound rental house, I have to wonder
why. This all seems terribly tragic to me, because I think that this camera hop
is the most important innovation since the boom pole. But folks, don’t take my
word for it –what you people should do is come on in and listen to the dang
Editor’s note: In that spirit, Gotham is offering a special deal for the
rest of the summer. Rent a
Zaxcom TRX900 Wireless Transmitter for 50% off our usual rate. If you like
it enough to buy one, make your purchase within 24 hours of returning it and
we’ll credit the cost of the first day’s rental towards your purchase.