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Old March 20th, 2017, 03:19 PM   #1
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wireless audio

For a theatrical job I have a client giving me line via RCA that I will plug into my (correction) Sony UWP-D11 bodypack with rca Y to mini cable which the will be sent into my camera's left channel.

How does stereo get handled with this setup? I noticed the bodypack lav mic has a stereo jack even I'm sure it's a mono mic and these type of transmitters send a mono signal.

Can someone educate me on how stereo is handled by these devices.

Last edited by Pete Cofrancesco; March 21st, 2017 at 07:51 AM.
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Old March 20th, 2017, 04:52 PM   #2
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Re: wireless audio

An RCA output is fo'sure unbalanced and line level.. however, some mixers just route the signal from the main balanced +4 outputs, so it could be higher than -10dB, so make sure the transmitter can handle it or some attenuation will be needed. l also don't know the Sony's input plug wiring, it could just short out everything out if the wiring is not 'right' I would test the set up before hand.
What input connection does the camera have? If if's an XLR input , it would probably be better to use a DI and feed the cam and transmitter mic level.
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Old March 20th, 2017, 05:11 PM   #3
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Re: wireless audio

Did you mean the UWP-D11 system with the UTX beltpack transmitter? I have the UWP-D16 with the beltpack and plug-on transmitters.

I don't know the exact connections in the beltpack transmitter jack, but one of the conductors is for power required by the lav element when the input is set to MIC Level.

You can set the input level in the menu to Line, but I haven't seen the exact connections listed anywhere to use, or if Sony has a ready-made line input cable for the beltpack transmitter.

I've only done this with the plug-on transmitter because it just uses a standard cable after setting Phantom Power to OFF and the Input Level to LINE.

These systems can't transmit stereo with a single set of 1 transmitter and 1 receiver that I know of.

For transmitting stereo line-level, I would use one of my Wi digital stereo transmitters as long as both the range and other 2.4gHz traffic was sufficiently low to be 100% reliable. Unless it's just for guide audio that is used for sync and will be replaced later. In that case, some dropouts are ok.
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Old March 20th, 2017, 06:22 PM   #4
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Re: wireless audio

Quote:
Originally Posted by Pete Cofrancesco View Post
For a theatrical job I have a client giving me line via RCA
Do you mean ONE RCA (implying monaural), or TWO RCA (implying stereo)?

Quote:
that I will plug into my Sony UWX-D11 bodypack with rca Y to mini cable
What is the "Y" for? Are you taking Left channel on RCA, and Right channel on RCA and summing them together into monaural?

Quote:
which the will be sent into my camera's left channel.
How does stereo get handled with this setup?
It sounds like you don't want stereo if you are recording on only one channel of your camera.
Making many assumptions in the absense of clarifying detail, it sounds like you are combining a stereo source into monaural using a "Y" adapter (or cable?)

Quote:
I noticed the bodypack lav mic has a stereo jack even I'm sure it's a mono mic and these type of transmitters send a mono signal.
No. The bodypack transmitter has a monaural input because it is a monaural transmitter (and receiver). It may have a TRS connector for the input, but TRS does NOT mean "stereo".

Quote:
Can someone educate me on how stereo is handled by these devices.
We still don't know what you mean by "handled"? We don't know what you are trying to do here?
If you only want to record monaural, you are already creating monaural (presumably) by taking stereo line-level signals and combining them together in a "Y"-something. Note that is generaly NOT an acceptable way of combining signals together. But it often works good enough for casual requirements.

If by "handle" you mean that you want to record stereo to your camera, then you must use some method that allows transmission of BOTH Left and Right signals. A monaural wireless system will handle ONE channel. So if you need wireless, then you must use TWO wireless systems. Or, of course, hard-wire the connection with two cables (or a stereo cable).
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Old March 20th, 2017, 07:41 PM   #5
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Re: wireless audio

Common practice for dance recitals is instead of playing the music from the sound booth it's done off stage with consumer cd/stereo thus the rca.

In this particular case I'm covering the job for another videographer who told me wants the stereo feed that will be coming from two rca outputs.

So the goal is to combine the stereo using a y cable to mono mini to plug into a wireless bodypack that will send the music to one of the channels of my camera. A shotgun mic will got to the other channel.

I was curious why the cables adapters that come with wireless transmitter/receiver have mini jacks that have the same rings as stereo jacks ie they look exactly like stereo head phone jacks not mono. I use the number of rings on a jack to identify if it is stereo.
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Old March 20th, 2017, 09:22 PM   #6
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Re: wireless audio

The two cables that come with the set are for the receiver output.

One cable is mini to XLR male and the other cable is mini to right-angle mini.

The right-angle mini is specified in the manual to connect to the recorder input and the straight mini connects to the receiver output.

What camera will you be using? How far away will the camera be from the stage?

Is it intended that the combined stereo signal that's recorded to one channel of the camera will be guide audio to be replaced later with the actual playback audio files or will it be used as the "actual" music in the edit with the shotgun mic as the ambient?
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Old March 20th, 2017, 11:50 PM   #7
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Re: wireless audio

Quote:
Originally Posted by Pete Cofrancesco View Post
... wants the stereo feed that will be coming from two rca outputs.

So the goal is to combine the stereo using a y cable to mono mini to plug into a wireless bodypack that will send the music to one of the channels of my camera. A shotgun mic will got to the other channel.
Using a Y-something is not a "proper" way to mix two signals together. Although it often works "good enough"

Quote:
I was curious why the cables adapters that come with wireless transmitter/receiver have mini jacks that have the same rings as stereo jacks ie they look exactly like stereo head phone jacks not mono.
They have two rings because they accommodate both mic-level and line-level signals. And because they accommodate both audio signals and microphone power. Exactly how the TRS is wired depends on the make and model of the body-pack transmitter.

Quote:
I use the number of rings on a jack to identify if it is stereo.
That is not reliable. And your case is an excellent example. Chances are that the tip of the TRS connector is meant for the monaural microphone and has a power voltage applied ("plug-in power" ~5V) and the ring may be for the line-level input. At least that is the "pinout" for Sennheiser TRS connectors.

I didn't find similar pinout information for Sony with a brief search. There is apparently a line-in cable for the Sony transmitters. EC-1.5BX although there appears to be no details about it online. So it is not even clear whether it is wired for mic-level or line level.

It is also confusing that the model number you cited ("UWX-D11") does not appear to be a valid Sony product number. The closest Google and Sony would admit to is: "UWP-D11"
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Old March 21st, 2017, 05:49 AM   #8
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Re: wireless audio

Richard my mistake it's UWP-D11. It can be set to mic or line input.

I see what you're saying the segments of a TRS can be used for different purposes. For headphones the Tip and Ring is for stereo where as in my application its for balanced mono.

I figured things out. I ran a test and discovered when a stereo signal is plugged into the transmitter, it discards the right channel and sends only the left.

Last edited by Pete Cofrancesco; March 21st, 2017 at 08:05 AM.
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Old March 21st, 2017, 07:36 AM   #9
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Re: wireless audio

Using simple "Y" adapter to mix stereo channels to mono is a kludge at best that relies on the output impedance of the source being sufficient to prevent overloading by the left-right cross connection. Not a good idea for low impedance sources.

Read the manuals for cautions, especially relative to the head phone output of the receiver. It appears to use a 3-contuctor (TRS) mini-phone for use with stereo headphones, but is mono output, and use of a 2-conductor plug will short the output.

Quote:
...wants the stereo feed that will be coming from two rca outputs.
Are you sure he doesn't want a stereo audio track (music). An alternative is to to get a copy of the music (tape, file, or CD) and mix it in later. But that involves more effort.

Is there an announcer or MC involved that needs to be recorded as well?

For information, the following link claims to show the mic connector interface equivalent:
https://www.google.com/search?q=BMP+...Gk27-ZsvIlZYM:

The transmitter bodypack appears to use the tip for audio, ring for DC power, and sleeve for ground return. Not a balanced input, but for short runs that is usually OK.

While it might not exactly match what is in the UTX, it can be used as a guide to help avoid problems. It clearly indicates that there would be risks involved in connecting some other non-BMP MIC source to the bodypack input with simple adapters not configured for the bodyback's design.
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Old March 21st, 2017, 08:00 AM   #10
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Re: wireless audio

A better way to mix a stereo signal to mono is to use a mixer, either panning the two inputs together or sending both of them equally to a post-fader Aux Send or a Group Output.

In any case, if some or all of the music is not mono compatible (due to oddity in the original mix or error in editing the music for the specific dance number), then there will be problems with the signal if mixed to mono through any method.

If it's just for guide audio to the camera and you don't have a mixer to place at the RCA outputs, I would only use one of the RCA outputs and send that to the camera. It's sufficient for sync purposes if you replace that "music" with the actual playback files later. Replacing later is more work but sounds much better. When it wasn't critical but was still going to be used as is, just one channel of the music is sometimes sufficient. It depends on the specific songs used.

Hopefully all sources, such as the MC mic, will appear equally at these RCA outputs that you have access to.

It needs to be tested with a multimeter if the Mic Power on the Sony beltpack transmitter input is automatically switched off when the input level is changed to Line. Otherwise that could also cause significant noise problems with the input signal or damage the transmitter input itself being shorted with the wrong cable.

You could use a wide-ranging-attenuation passive direct box like the Rolls DB25b, RCA to TS 1/4-inch male adapter cable and the Sony EC-1.5BX input cable to connect to the beltpack transmitter. That would be the most simple, safe and easily adjusted way to do it.

Last edited by Jay Massengill; March 21st, 2017 at 09:38 AM.
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Old March 21st, 2017, 11:53 AM   #11
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Re: wireless audio

Thx Jay getting the Rolls DB24 seem like the safest and most appropriate solution.

Don getting the original audio that doesn't work for a number of reasons. The most important is the music isn't played continuously, it's started and stopped for each dance. So you would be spending hours in post syncing 40+ songs.
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Old March 21st, 2017, 01:38 PM   #12
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Re: wireless audio

I hadn't seen the relatively new DB24. Let us know if you have any oddities with the music signal when summing to mono, and how it goes with interfacing to the beltpack transmitter input.

I replace and sync about 45 songs for our dance recital. It does take a lot of time, but only because it's a lot of material. If you have a good guide track all you have to do is match the waveform start for each, it's easy depending on which software you use. And I'm going for maximum quality since I'm personally invested in the outcome.
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Old March 21st, 2017, 02:13 PM   #13
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Re: wireless audio

Quote:
Originally Posted by Pete Cofrancesco View Post
I figured things out. I ran a test and discovered when a stereo signal is plugged into the transmitter, it discards the right channel and sends only the left.
One more problem to mention here. Music is often mixed with some of the sound (vocals or instruments) sent to just one channel to emphasize stereo effect. Or for what ever reason was in the mind of the producer at the mix. Discarding one channel means you could be discarding essential beats, music, or vocals.

This is nothing new, a good example of this mixing is the old classic I Feel Good by James Brown. The trademark opening line of the tune when he screams I feel good is only on one channel (right, if I remember correctly). If only the left channel is played you will barely hear the words at all. How do I know that? Those three words were a critical Que as part of a client show. I got burned when it turned out the FOH mixer sent only the right side out of the mixer and daisy chained all PA speakers. My bad, I was the TD and I know AV guys love shortcuts like that. I should have checked it.

So the Y is a bad idea. Why don't you just mic the speakers coming out of the box? I have never made a recording that way but the wedding guys do it all the time. Or put a recorder there, even if as a back up.

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Old March 21st, 2017, 02:45 PM   #14
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Re: wireless audio

Good points. One caveat I'm filming this for another videographer who's double booked and is very particular on how he wants it done. It's not my place to disregard his instructions it's his client and he will be editing it.

I'm mainly asking these questions to better educate myself.
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Old March 21st, 2017, 03:28 PM   #15
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Re: wireless audio

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Originally Posted by Steven Digges View Post
Why don't you just mic the speakers coming out of the box? I have never made a recording that way but the wedding guys do it all the time. Or put a recorder there, even if as a back up.
Is there any chance of doing that plus getting a copy of the CD(s) - then he can use the mic recording as a reference and sync up the much better audio from the CD(s) later.

I've managed to persuade bands to part with copies of unreleased singles in the interest of getting decent audio on videos from a promo tours. Where commercial CDs have been used I just got a copy (and made sure someone else dealt with the copyright :-)
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