wireless lavalier minijack to XLR noise

BONLEV

BONLEV

Active member
Hello,

I bought a wireless lavelier mic from boya (boya BY-WM4 pro-K2 duo)

Because this has no xlr output I tested it first with my GH5S and sounded great (sorry, no english here):

https://www.youtube.com/watch?v=VIkq3hqZ-cM&t=150s

for my DVX200 a friend gave me a XLR to minijack piece but My sound has background noise. I don't know if my settings are not ok or the problem is with that "xlr to minijack adapter"

Here is my test with that adapter on the dvx200

https://www.youtube.com/watch?v=SUc9_Zstb2g&feature=youtu.be

I attached some pictures from my settings

P1011399.jpgP1011400.jpgP1011401.jpgP1011402.jpg146973436_2509774859331826_5365233169650590982_n.jpg
 
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Tested the same setput with my Sony fs100 and the same results. Strange thing is when recording i hear no noise in my headphone plugged in the receiver. When playing what i recorded the noise kicks in. The lavalier is on maximum output sound
 
I have a couple of suggestions. The adaptor looks like a straight TRS female to XLR 3 pin and these are usually wired jack sleeve to XLR PIN 1 and then the tip and ring to pins 2 and 3. I'm guessing the connector on the end of the cable. Is it a TS or TRS jack? It is possible that you are taking the feed from the tip and ring - and there's enough difference for something to be audible on the camera's mic level input. Or, I guess the mic plug could be unbalanced by shorting pin 2 to pin 1 in the XLR but the jack to XLR has been unbalanced by shorting pin 3 to pin one. One trick is to see if gently slowly removing the jack from the adaptor suddenly reveals loads of level as one pin unconnected. The switch settings look right - however is 40dB the highest gain setting in the menu? The noise comes from the output of the receiver being too low on the connection you have. My best guess is just wiring confections in the unbalanced to balanced end to end.
 
146385874_253035283054771_5863385883355512692_n.jpg

3,5mm tot TRS audio output cable. I see no difference in the 2 ends of this cable but both ends fit.
I did you trick (gently removing the jack from adapter) and with that I think I found what causing this.

When the jack is now half connected into the XLR the sound input is much higher in the camcorder! Now i can see the audio bars on the display.

But there is also background noise. I attached a picture.
 
According to the Boya manual, the output is line level and you have the camera set for mic level. Also according to the manual, the output is stereo. This coincides with the GH5S TRS input which is also stereo. You are connecting TRS stereo to a mono XLR connection. I'd suggest the following.

- Set the camera to line level.
- Rewire the adapter:
- Connect the tip of the Boya to pin 2 of the XLR.
- Connect the sleeve to pin 1 & 3 of the XLR.
- Leave the ring of the TRS disconnected.
 
That would indeed seem to solve the connection issue - and then the camera mic/line switch can sort the level differences out.
 
Paul & Paul,

Thx both for your help already! I have read the manual again carefull but about that "line level" If I read the manual it says "line out" on the receiver which I did.
If I set the camcorder to "line level" there almost no sound coming in!

With "mic" it is much louder but background noise. So would my problem could solved when buying a 3.5mm mini jack (same as TRS?) to XLR male cable?
I tried this solution because a friend gave it to me but it seems this method with the adapter is causing the noise.
 
Many cameras have their mic inputs and line inputs simply selecting a pad to cope for changes in level, plus the mic setings can also inject phantom power. The noise issue would normally be a ratio - you have so much wanted signal, and so much unwanted signal (noise) - and the difference between them is a ratio - which is fixed. The fact you are getting noise means one of two common things. The audio output from the device is turned down so it brings the noise floor that is always there, closer to the wanted signal - the camera then amplifies it, bring up the background noise - Something in your connection setup is wrong. It could be that your transmitter has adjustable gain - so you are not sending enough - meaning the receiver introduces the noise - and in an RF link there is always noise. So - and I don't know your system, is there a gain switch at the transmitter end? Sennheiser, for example, have 3 different microphone sensitivities, to cope with bellowing singers, or whispering actors. Set the wrong one and you get noise at one end, or nasty distortion at the other. Receivers then have controls to adjust their output level, and cameras offer you mic or line and gain. Getting these all correct is gain staging. Getting it wrong generates noise and/or distortion. Cabling faults can reduce levels too. It was mentioned the receiver output is stereo - but you are feeding it with a mono transmitter, so I suspect it's not stereo at all, but has a socket wired for 'stereo' - but the left and right have exactly the same signal on them. I actually have a synth here that has a stereo output - as in socket, and it is possible to miswire this with a few cables I have and what comes out of the miswired cable (using ONLY the tip and ring of the jack) is a very tiny audio signal - which is actually the difference between the L and R, and turning the gain up to use this produces a very noisy signal.

One of these scenerios is what is happening - which one is down to you to identify.
 
Amazon Q&A says this device can't be used with XLR. I've had similar problems trying to plugin devices with mini 3.5 outputs into camcorder xlr jack.

It's some combination of what others have said:
1. You're taking an unbalanced stereo output and plugging into an xlr input that expecting a balanced mono feed.
2. The wireless receiver isn't sending out a strong enough signal.
3. The camcorder amplifier isn't good enough boost this weak signal without amplifying the noise.

The bottom line you can't use it with your camcorder. You would have to buy a more expensive wireless system designed to work with XLR devices.
 
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Right now, you don't know what the cable and adapter are doing. It is highly likely, the adapter is wired wrong. Many TRS/XLR adapters tie tip to 2, ring to 3, and sleeve to 1. That could definitely give you a low signal and noise problems.

I agree with Paul L about the stereo not being really stereo. One way to confirm how the Boya and the cable are wired is to see if when connected to the GH5S, does the signal show up on both channels of the GH5S. If it does, that that indicates that the Boya is driving tip and ring with the same signal. That would not work for an XLR connection.

In any case, make up your own cable and see if that fixes it.
 
docmoore, nice suggestion, but with there being no ring or sleeve separation on the TRS connector, that cable shorts ring and sleeve together. More than likely, Boya is driving both tip and ring with the same signal. So that cable would short the ring signal out to ground.
 
Could very well be the cable. I know my Sony wireless system comes with a specifically made 3.5 to xlr cable. You'd have to either re-solder or buy one wired correctly.
 
I was thinking the same thing, but from the pictures, it's a plain straight-through TRS/TRS cable and then that long adapter sticking out of the camera (uggh). He will be miles ahead making a TRS to XLR cable with a right angle on it. Sound mixers use this cable all the time in their mixer bags, but I don't see it available from Trew Audio. Most mixers make up their own specialized cables.

PM me your address and I'll make one up and send it to you. It might take a while to get to you with the way parcel's are being delayed.
 
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Paul F said:
That cable won't work because there is not sleeve. See my other post about it.
Click to expand...
Ok I see what you are saying the mono TS would short plugged into TRS stereo jack.
I assume that the Wireless receiver is sending the mono signal to both the right and left channel so when plugged into a consumer level device a silent channel won't be recorded that you'll have to fix in post. I'm curious if a balance xlr input is expecting polarity reverse to illuminate noise why would feeding it the identical mono signal cause a problem?
 
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