Wireless from the Mixer to the Recorder

[Peter Stockley]

Hi everyone,
I’m recording video in settings such as a theater/church/school/concert hall etc, usually with a stage or platform at the front and upstairs balcony at the rear. To do this I will be using a Tascam DR100 external audio recorder (containing two XLR inputs) along side my camera with an attenuator cable going from the line-out of the recorder to the mic-in of the camera for the purpose of synching in post. I need to be able to move around while doing this. I have a Rode NTG-2 shotgun mic which is not suited for this purpose and thought a decent stereo mic would be a good solution so I went to a local store to check some out.

However, the audio salesman told me that no mic would be a good choice in such a situation and that my only alternative was to get the microphones closer to the subjects being recorded. I am unable to do this, though I generally don’t have a problem being allowed to take a stereo or mono feed from the mixing console located in the balcony. I could run a 100ft long or longer XLR cable from the balcony down to the lower floor and use another person as a cable puller to follow me around while I shoot video footage, but this is not practical, neither would I be allowed to do so, which leads me to my question.

Is it possible to capture a live feed from the stereo/mono XLR outputs of the mixing console into the XLR inputs of the Tascam DR100 audio recorder using a wireless system? Normally a lavaliere mic and transmitter would be located on the subject, with the transmitter sending a signal back to the receiver located and hooked up to the mixing console where the audio can easily be recorded.

I asked the audio salesman at the store if it were possible to reverse the process. In other words, the transmitter would be hooked up to the mono/stereo live feed on the mixer sending the live feed back to the receiver which I would carry with me in the same way I would carry a field mixer which would feed the signal into the DR100 recorder.

A couple of questions came with this possible scenario.
1. The receiver would have to be battery operated. Is their such a thing?

2. The salesman said the transmitter could be hooked up to the mixing console but it would be a
balanced signal (coming from the mixer), dropping down to an unbalanced signal (going into the
transmitter), back to a balanced signal (from receiver into recorder).
If all of this were to work, how much would the signal quality be affected going from balanced to
unbalance back to balanced using a wireless system?

3. There is also the possibility that their is a mic that would yield acceptable results in such a situation.
Is their?

I’m sure there is a decent solution to this problem and probably equipment now available that would do it more efficiently that I am not aware of, so some solid input would be much appreciated.

Thanks

[Steve House]

What is the nature of the performance you're recording? Single speaker, musical group, chorus or choir, variety acts, opera, dramatic play, what? Optimum mic'ing is dependent on the nature of the source(s) to be recorded.

You certainly can run a wireless link from a mixer back to the recorder/camera but if you are recording in stereo you're going to need 2 transmitter/receiver pairs to do it, one pair for the left channel and one for the right. And yes, there are many wireless units that have battery powered receivers - they are extremely common. As for how to hook the mixer output to the transmitters, first of all what mixer are you using? Does it have line level or mic level outputs or can you choose one or the other? Anything else running off the mixer, such as PA, or is it dedicated exclusively to your audio feed?

Going from balanced to unbalanced or vice versa shouldn't be an issue if it's done right.

As far a mic that will give decent recordings when located in the balcony at the back of an auditorium, such critters simply don't exist.

[Peter Stockley]

Steve
I’m not sure what type of mixer it is. Are you referring to make and model?

The mixer s not dedicated to my audio feed.

The mixer is running a PA system with also a wireless setup with the wireless receiver in the opposite part of the building. I’m unsure if everything is run wirelessly but the sound engineer said something about getting a transmitter to hang on my belt and sending the audio feed into my recorder but I would need to buy the receiver with the same frequency as the one they are using (and he doesn’t know what that is).

Of course the other question would be how to go from the 3.5mm connection on the receiver to the XLR inputs of the recorder.

I think there are both line level and mic level outputs available at the mixer. There are dual stereo XLR outputs and one mono XLR outputs for live feed which I have used before with cables. I realize that recording stereo would require twice the equipment so I would probably just record mono to both channels on the recorder.

As far as the mic located in the balcony at the back is concerned I was meaning one that I could attach to my video rig which would go wherever I go whether back in the balcony, on the lower floor, or right next to the sound source.

Note: I am not very familiar with audio equipment and like many others, I have a limited budget but want the best setup I can afford.

[Edward Carlson]

Alternatively, send the output from the recorder to the camera. In the industry, it's called a wireless hop. If it's only for syncing, a mono, low quality feed will work. The possibility of dropping the wireless signal (especially with TWO systems) is too high when the recorder is your only audio source.

Wire the recorder, send a scratch track to the camera with a wireless hop.

[Peter Stockley]

I’ve never heard of a wireless hop before, but I assume you mean sending a line out signal from the recorder to the line in of the camera. If that is the case, I am already doing this via an attenuator cable. What I need is getting a wireless feed from the mixer to the recorder via the mixer and recorders XLR outputs and inputs. The only other way is drag cables (not practical), or put a mic on top of the camera (which I am told does not yield good results).

[Edward Carlson]

Maybe I missed something, but why do you need to carry the recorder around with you? It seems that you are only recording the feed from the house mixer, right? It seems to me there's no reason to have to carry the DR-100 around.

House mixer-------recorder------wireless tx ) ) ) ) wireless rx-----Camera.

[Mario Vermunt]

I agree with Peter. There is no need to carry the recorder with you. In my opinion it is not necessary to transmit the audio to the camera as well. Just use a simple (built in) mic on the camera. That should be enough for syncing purposes.

[Peter Stockley]

Thanks for your input guys, but here are a few more thoughts I have. What am I missing here?

A common method used by most run and gun videographers is mounting an external recorder on top of the camera to record the audio while at the same time sending the same signal via an attenuator cable to be recorded by the camera. I am by no means very knowledgeable regarding audio, but this method appears to have some advantages.

I had thought of placing the recorder next to the mixer and doing as you suggested. The potential problem with this method is that if the distance of the camera from the sound source, is substantially different from that of where the mixer is recording the sound source, their may be problems with synching in post. I am told that there is roughly one frame lost for approximately every thirty feet the audio signal has to travel when recording with the camera and external recorder in different locations, resulting in “sync drift” in post editing. Having the recorder mounted next to the camera and sending the exact same copy of the signal into the camera would seem to be the best solution.

Another consideration, is that I would not be able to monitor the audio on the recorder and the camera at the same time. The camera would be recording the “in house” sound from both the subjects and PA system, while the mixer would be recording the audio from all source’s via microphones. Depending on the experience of the individual on the mixer, I could end up with two different audio sources
resulting in difficult post synching.

[Edward Carlson]

Originally Posted by Peter Stockley

... if the distance of the camera from the sound source, is substantially different from that of where the mixer is recording the sound source, their may be problems with synching in post. I am told that there is roughly one frame lost for approximately every thirty feet the audio signal has to travel when recording with the camera and external recorder in different locations, resulting in “sync drift” in post editing. Having the recorder mounted next to the camera and sending the exact same copy of the signal into the camera would seem to be the best solution.

Thus the wireless hop suggestion. The recorder will send its signal to the camera wirelessly, so it will be exactly in sync.

[Peter Stockley]

Which brings me back to my first question. How to best set up a wireless feed from the mixer to the recorder so I can perform a wireless hop?

That is of course, unless there is an external mic I can place next to the camera and recorder to record the audio that would do a decent job thus taking the mixer out of the equation altogether.

[Edward Carlson]

No, no. You have it mixed up.

The wireless hop goes from the recorder to the camera.

The recorder is wired to the mixer, and they stay back at the sound booth. The recorder's output goes into a wireless transmitter.

The wireless receiver is attached to the camera, and it gets the signal from the recorder (which is back at the sound booth.)

Now the camera is recording a "scratch track," a mono, low-quality-is-okay track to sync to the higher quality track from the recorder later.

Again, there is no reason to carry the recorder around with you, since the only source for the recorder is the house mixer, which lives on a desk.

[Greg Miller]

Also, consider that you might have dropouts, noise hits, or other flaws in the wireless transmission.

You do NOT want those flaws on your final good recording. That's why the recorder should be connected directly to the mixer.

But it is OK to have a few wireless flaws in the camera's scratch track. So it makes perfect sense to use the wireless link between the recorder's output and the camera's input.

[Steve House]

Originally Posted by Peter Stockley

...

I am told that there is roughly one frame lost for approximately every thirty feet the audio signal has to travel when recording with the camera and external recorder in different locations, resulting in “sync drift” in post editing.

...

Not quite. Sounds travels slower than light. What matters is the distance the sound has to travel in air before it gets to the microphone. You insert 1 frame of delay for each 30 feet the microphone is away from the sound source. A microphone at the speaker's position feeding a recorder 100 feet away through a cable has essentially no delay.

[Peter Stockley]

Ah-ha, now I understand. I have never heard anyone so much as hint of such a setup you have mentioned on any of the forums. Probably because they are all run and gunning outside where they have no mixer or are carrying a portable field mixer with them.
In any case, it make perfect sense. All I needed was a little mores descriptive clarification.

Ok then, now you have set me straight and enlightened me, can you suggest a wireless system I might use without breaking the bank. My understanding of a normal wireless system is receiver, transmitter and a microphone. I won’t need the microphone and I see there are different sizes of transmitters and receivers available with different features and connections.

Descriptive clarification please, lol.

[Edward Carlson]

Sennheiser G3 (or a used G2 system.) Make sure you get a system with the battery powered receiver. They make an AC powered receiver for installation, which is not what you want.

You might also need an adapter cable from the output of the recorder to the input of the transmitter. The Sennheisers use a weird screw-on 1/8" plug, but an adapter cable can be made or bought at places like B&H or Trew Audio.