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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Wireless and Communications => Topic started by: Matt Hill on February 04, 2021, 02:15:00 pm

Title: Wireless lav audio problems
Post by: Matt Hill on February 04, 2021, 02:15:00 pm
Hi everyone, new member here with frustrating audio problem.

I am using Sony UTX-B03 transmitters with URX-P03D receiver and Auto Set the frequencies at each shooting location. I keep coming back with terrible audio that almost sounds as if the signal is struggling. Examples of the audio can be found here:

Distorted File 1 (https://drive.google.com/file/d/1kiSVVAOuh0UPqnjjXtpeQnzeVvjxyaFI/view?usp=sharing)

Distorted File 2 (https://drive.google.com/file/d/1m-FT_osWCz8aDZpmo8bwIF39Z9gxj2Zt/view?usp=sharing)

When I return to my studio and check the mics without changing any settings at all, they will always sounds fine and work fine. Can anyone help with what the problem could be or what is causing the audio loss? It is happening with all 6 of my mics so is not faulty equipment.

Many thanks in advance.
Title: Re: Wireless lav audio problems
Post by: Lee Buckalew on February 04, 2021, 02:20:24 pm
Hi everyone, new member here with frustrating audio problem.

I am using Sony UTX-B03 transmitters with URX-P03D receiver and Auto Set the frequencies at each shooting location. I keep coming back with terrible audio that almost sounds as if the signal is struggling. Examples of the audio can be found here:

Distorted File 1 (https://drive.google.com/file/d/1kiSVVAOuh0UPqnjjXtpeQnzeVvjxyaFI/view?usp=sharing)

Distorted File 2 (https://drive.google.com/file/d/1m-FT_osWCz8aDZpmo8bwIF39Z9gxj2Zt/view?usp=sharing)

When I return to my studio and check the mics without changing any settings at all, they will always sounds fine and work fine. Can anyone help with what the problem could be or what is causing the audio loss? It is happening with all 6 of my mics so is not faulty equipment.

Many thanks in advance.

What are you recording onto?
What is the signal path for the audio?

Lee
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 04, 2021, 02:50:58 pm
When you check the system after the fact are you using the exact same set up?
Like Lee asked what is the set up?
I sounds like some heavy compression expansion pumping going on.
What does it sound like monitored directly from the wireless receiver?
Do you have the issue with just one mic turned on?
Title: Re: Wireless lav audio problems
Post by: Matt Hill on February 04, 2021, 03:06:16 pm
When you check the system after the fact are you using the exact same set up?
Like Lee asked what is the set up?
I sounds like some heavy compression expansion pumping going on.
What does it sound like monitored directly from the wireless receiver?
Do you have the issue with just one mic turned on?

Thanks for the replies. Set up is XLR direct into Sound Devices 702T.
I agree it sounds like heavy compression but can't be because it is the exact same set up when returned to studio - not a single setting changes on any device. And it sounds beautiful.
Have also tried this capturing into MixPre-6 and same problem.
Yes, issue remains with one mic on. I can have 2 mics running and different amounts of the problem with each mic. Monitored directly from receiver sounds exactly same problem.
Title: Re: Wireless lav audio problems
Post by: Lee Buckalew on February 04, 2021, 03:53:24 pm
Thanks for the replies. Set up is XLR direct into Sound Devices 702T.
I agree it sounds like heavy compression but can't be because it is the exact same set up when returned to studio - not a single setting changes on any device. And it sounds beautiful.
Have also tried this capturing into MixPre-6 and same problem.
Yes, issue remains with one mic on. I can have 2 mics running and different amounts of the problem with each mic. Monitored directly from receiver sounds exactly same problem.

Are you running on Battery onsite but DC adapter in the studio?

Lee
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 04, 2021, 06:42:53 pm
Does this happen every time you go out on location anywhere or is it just at one
location?

I want to say a companding setting issue on the receiver but.....that would not explain why it works in the studio, yes I looked up the receiver.
Title: Re: Wireless lav audio problems
Post by: Martin Morris on February 04, 2021, 07:18:30 pm
When you check the system after the fact are you using the exact same set up?
Like Lee asked what is the set up?
I sounds like some heavy compression expansion pumping going on.
What does it sound like monitored directly from the wireless receiver?
Do you have the issue with just one mic turned on?

LINKY
https://cdn.sounddevices.com/wp-content/uploads/2020/08/702t_UserGuide.pdf (https://cdn.sounddevices.com/wp-content/uploads/2020/08/702t_UserGuide.pdf)

it could be a similar issue with the MixPre-6 - try reducing your input from the Sony into the sound devices. Also watch for the "limiter" LED. It should engage now and then or not at all, and should not be "ON" permanently.

Just a thought ... cheers Martin
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 04, 2021, 08:22:32 pm
LINKY
https://cdn.sounddevices.com/wp-content/uploads/2020/08/702t_UserGuide.pdf (https://cdn.sounddevices.com/wp-content/uploads/2020/08/702t_UserGuide.pdf)

it could be a similar issue with the MixPre-6 - try reducing your input from the Sony into the sound devices. Also watch for the "limiter" LED. It should engage now and then or not at all, and should not be "ON" permanently.

Just a thought ... cheers Martin

And the only thing that is not the exactly the same as on a location shoot when testing in the studio
is the person at the mic! Maybe the studio test is with a softer spoken person and or different mic positioning not driving the recorder as hard.
Title: Re: Wireless lav audio problems
Post by: Pete Erskine on February 05, 2021, 12:08:07 am
I am using Sony UTX-B03 transmitters with URX-P03D receiver and Auto Set the frequencies at each shooting location. I keep coming back with terrible audio that almost sounds as if the signal is struggling. Examples of the audio can be found here:

Sounds like the TX are overloaded.  Turn down the gain on the mic pre and make sure the mics are 6" from the speakers mouth - also sounds like hey are too close.
Title: Re: Wireless lav audio problems
Post by: Russell Ault on February 05, 2021, 03:46:24 am
[...] I agree it sounds like heavy compression [...]

I'll buck the trend: to me it sounds like (slow) gating, not compression. To my ears it sounds like the level increases just after the speaker emphasizes a word.

To continue bucking the trend, my vote is that the RF isn't being driven hard enough, and that the reason it works in the studio but not in the field is that your location talent is quieter and/or being mic'ed at a greater distance-to-mouth than your in-studio tests.

I'm surprised no one has asked this yet (since, to my mind, it's the first question to ask when troubleshooting an RF-related gain-staging issue): what do the levels on the TX (or, if you can trust that they're the same, the RX) look like while the mic is on the talent? No point in trying to adjust levels on the recorder if the RF stage isn't gained properly (especially with FM RF, which cares about gain-staging more than just about any other audio device).

-Russ
Title: Re: Wireless lav audio problems
Post by: Keith Broughton on February 05, 2021, 07:12:47 am
Matt, you say "when you come back". Is no one monitoring the audio on location? If not, why not? If so, at what point in the signal chain are you monitoring?
I think those Sony's have a headphone out on the RF receiver so you can check audio starting at the receiver.
On location is the place to trouble shoot this problem if, as you say, the equipment works correctly in studio.
Title: Re: Wireless lav audio problems
Post by: Matt Hill on February 05, 2021, 10:04:56 am
Matt, you say "when you come back". Is no one monitoring the audio on location? If not, why not? If so, at what point in the signal chain are you monitoring?
I think those Sony's have a headphone out on the RF receiver so you can check audio starting at the receiver.
On location is the place to trouble shoot this problem if, as you say, the equipment works correctly in studio.

These are all great suggestions, thanks everyone.
Am about to head back to location we had this problem yesterday to test everything and will post back results.
I work for a school district so am on several of our 42 school campuses, and this is happening more and more frequently on several campuses. It is worse in some locations within those campuses. At some campuses there is no issue at all. That makes me think it is something to do with frequency or wireless connection? I have auto-set numerous times at the location with no improvement in results.
Mic is always approx. 6 inches from mouth. Level received into field recorder is always low even when pushed when this problem is happening.

Will go test this morning with all your valuable input and post back results. Thanks again everyone.
Title: Re: Wireless lav audio problems
Post by: Tim McCulloch on February 05, 2021, 10:16:18 am
These are all great suggestions, thanks everyone.
Am about to head back to location we had this problem yesterday to test everything and will post back results.
I work for a school district so am on several of our 42 school campuses, and this is happening more and more frequently on several campuses. It is worse in some locations within those campuses. At some campuses there is no issue at all. That makes me think it is something to do with frequency or wireless connection? I have auto-set numerous times at the location with no improvement in results.
Mic is always approx. 6 inches from mouth. Level received into field recorder is always low even when pushed when this problem is happening.

Will go test this morning with all your valuable input and post back results. Thanks again everyone.

What frequencies are you using? Anything above 600mHz?
Title: Re: Wireless lav audio problems
Post by: Keith Broughton on February 05, 2021, 11:22:22 am
When you get on site, turn on the receivers but do not turn on the transmitters and check the RF meter on the receiver to see if there is any RF in that location.
Title: Re: Wireless lav audio problems
Post by: Matt Hill on February 05, 2021, 03:52:33 pm
When you get on site, turn on the receivers but do not turn on the transmitters and check the RF meter on the receiver to see if there is any RF in that location.

Tested at problem location (school library) and discovered it is 100% related to specifically where I was. Listen to the file below - begins outside the library in a boomy hallway and sounds OK ... once I step into the library within seconds all the audio is sucked away and I am back to the same problem.

Test Outside to Inside Library (https://drive.google.com/file/d/1PjWmnx4fqgmUKYG0TGSZSwRbOJkAmLnE/view?usp=sharing)

This makes me feel it is absolutely signal interference, maybe frequencies or something. But it is happening on many of our campuses so could it be related to the wifi system or something? Any settings or frequencies I could choose that avoid those of wifi?

To answer earlier post questions and suggestions, I'm running battery onsite and in studio - literally not a single change in setup between locations, but studio offers perfect audio.
Played with companders on both RX and TX - every single combination of UWP. UWP-D and WL800, none fixed they problem, audio was almost the same every time, but always bad.
The levels are all low when this problem happens - 1/2 and lower on TX, 1/3 and lower on RX, and very low into 702T and MixPre-6 and I switched limiter off completely so I don't think the levels are the issue or anything is overloaded.
I have been monitoring audio directly from the receiver and have exactly the same results as my recording equipment. Really believe this is a signal issue somehow. Any help again truly appreciated.



Title: Re: Wireless lav audio problems
Post by: Russell Ault on February 05, 2021, 04:18:03 pm
{...} The levels are all low when this problem happens - 1/2 and lower on TX, 1/3 and lower on RX, {...}

At the risk of some postmortem equine flagellation, this still sounds like not enough TX input level to me. In your most recent test audio, to me the door sounded about the same both inside and outside the library, but you started speaking more quietly (and therefore closer to the RX's noise gate) when you entered the library (which, to be fair, we all do when we enter libraries). :) From your description, the meters are backing me up on my "not enough level" assessment.

While some companding circuits are more forgiving than others, they all work best with an input signal that's close to the TX's limiter threshold. As long as you're seeing such anemic levels on the TX and RX I'd expect to have weird audio problems, and the only solution to my knowledge is getting more audio level into the TX.

What are your IN LEVEL and ATT settings on the UTX-B03?

-Russ
Title: Re: Wireless lav audio problems
Post by: Tim McCulloch on February 05, 2021, 04:23:01 pm
At the risk of some postmortem equine flagellation, this still sounds like not enough TX input level to me. In your most recent test audio, to me the door sounded about the same both inside and outside the library, but you started speaking more quietly (and therefore closer to the RX's noise gate) when you entered the library (which, to be fair, we all do when we enter libraries). :) From your description, the meters are backing me up on my "not enough level" assessment.

While some companding circuits are more forgiving than others, they all work best with an input signal that's close to the TX's limiter threshold. As long as you're seeing such anemic levels on the TX and RX I'd expect to have weird audio problems, and the only solution to my knowledge is getting more audio level into the TX.

What are your IN LEVEL and ATT settings on the UTX-B03?

-Russ

And to my point - desensitizing of the receiver inputs by other RF sources.  We need to know where he's at and what frequencies he's using.
Title: Re: Wireless lav audio problems
Post by: Matt Hill on February 05, 2021, 04:29:15 pm
And to my point - desensitizing of the receiver inputs by other RF sources.  We need to know where he's at and what frequencies he's using.

Hi Russ - IN LEVEL is set to MIC and I just left ATT at 0. I did try pushing ATT up and up while testing this morning, but this just seemed to increase the volume and the problem. Also, the male voice level in the original clip2 was much stronger but still had same underlying audio issue. Shouldn't I be able to throw a lav on someone and even if they have low level, be able to capture something without this "gating" effect?

Tim - I was AUTO SET-ting in group 1 from my receiver and for this test it was giving me 478.125. BAND on receiver set to TV14-17 but I have tried it on the other settings, 18-21 and 22-25. Have AUTO-SET many times and keep getting same result.
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 05, 2021, 04:41:52 pm
Like Keith asked with the transmitters off do you see any RF receive level on the receivers?
What frequency group are you using, It does appear that Sony uses any WIFI bands for that series of wireless.

A really wild idea..do they use lots of LED lighting in the library, some LED lights pump out a lot of RF noise.

Going with Russell's idea bring up the transmitter audio level till you just at the point of hitting the peak light.

For what it's worth from the wording on the wireless system info I think it's an analog system that uses digital companding.


I type slow you answered some of those questions while I was typing!!
Title: Re: Wireless lav audio problems
Post by: Russell Ault on February 05, 2021, 04:57:58 pm
{...} Shouldn't I be able to throw a lav on someone and even if they have low level, be able to capture something without this "gating" effect? {...}

It depends on the companding circuit, but basically, no.

Without a companding circuit, the dynamic range of a US-legal UHF FM wireless microphone is only about 50 dB from noise floor to max level. Obviously, 50 dB is...pretty terrible, and ideally should be about twice that. To fit 100 dB of signal into 50 dB of actually dynamic range, wireless microphone manufacturers use various forms of companding, similar in nature to Dolby B, but with some added twists.

The exact makeup of any given companding style is a trade secret, but the gist is that there are one or more compressors on the TX to reduce the signal's dynamic range, and then one more expanders on the RX to restore it. Of course, if you've ever tried to run a compressor and an expander in series, you'll know that you'll never quite get out what you're putting in, so there's a great deal of artistic license that goes into designing these systems, with different trade-offs being chosen even for different product lines from the same manufacturer.

In the end, though, the result is the same: the appearance of significantly increased dynamic range, but with significantly reduced linearity. How well these systems performer at the fringes (i.e. with a really hot or a really cold input signal) is one of the many compromises to be made, and a design choice inherent to the specific companding style.

Something else I should have asked earlier: given that you're already at ATT 0, what capsules are you using?

-Russ
Title: Re: Wireless lav audio problems
Post by: Tim McCulloch on February 05, 2021, 05:08:34 pm
Like Keith asked with the transmitters off do you see any RF receive level on the receivers?
What frequency group are you using, It does appear that Sony uses any WIFI bands for that series of wireless.

A really wild idea..do they use lots of LED lighting in the library, some LED lights pump out a lot of RF noise.

Going with Russell's idea bring up the transmitter audio level till you just at the point of hitting the peak light.

For what it's worth from the wording on the wireless system info I think it's an analog system that uses digital companding.


I type slow you answered some of those questions while I was typing!!

I'm liking this...


Tim - I was AUTO SET-ting in group 1 from my receiver and for this test it was giving me 478.125. BAND on receiver set to TV14-17 but I have tried it on the other settings, 18-21 and 22-25. Have AUTO-SET many times and keep getting same result.

This sounds very much like broadband noise from LED systems.
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 05, 2021, 07:30:17 pm
I'm liking this...

This sounds very much like broadband noise from LED systems.

And an easy test is go into the library, turn out all the lights and record a test message.
Title: Re: Wireless lav audio problems
Post by: Russell Ault on February 05, 2021, 07:33:07 pm
{...}
Tested at problem location (school library) and discovered it is 100% related to specifically where I was. Listen to the file below - begins outside the library in a boomy hallway and sounds OK ... once I step into the library within seconds all the audio is sucked away and I am back to the same problem.

Test Outside to Inside Library (https://drive.google.com/file/d/1PjWmnx4fqgmUKYG0TGSZSwRbOJkAmLnE/view?usp=sharing)
{...}

Sorry, one more question, when you were doing this test, where was the RX?

-Russ
Title: Re: Wireless lav audio problems
Post by: Matt Hill on February 07, 2021, 04:59:49 pm
Sorry, one more question, when you were doing this test, where was the RX?

-Russ

All fluorescent lights in the library, no LEDs ... also most testing was done with RX and TX close to each other, I know they should be several feet apart at least, but on the actual shoot they were and no difference.
Brought the mics home this weekend to test and just simply beautiful audio, no need to touch anything, even with low level whispering I can hear the room tone beautifully, it doesn't come in and out, unlike this problem I'm having on campuses where it seems like the room tone and everything is just sucked away.
I definitely don't have the knowledge or experience of suggestions I'm getting, but I keep coming back to signal interference since this is so clearly related to the locations I am in. Not sure if there's a fix or workaround bc I've been through every setting on these things and compander change or endless re-syncing of autoset doesn't fix this. Right now my only solutions are boom or change location which is a problem since it appears to happen in some locations on every campus I visit :(
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 07, 2021, 05:49:35 pm
Could you go with a hardwired lapel mic?

I don't want to beat the LED idea to death but there are LED fluorescent light tubes that look
like a fluorescent tube only brighter and are drop in replacements.
Title: Re: Wireless lav audio problems
Post by: Russell Ault on February 07, 2021, 06:10:53 pm
{...} Brought the mics home this weekend to test and just simply beautiful audio, no need to touch anything, even with low level whispering I can hear the room tone beautifully, it doesn't come in and out, unlike this problem I'm having on campuses where it seems like the room tone and everything is just sucked away.
I definitely don't have the knowledge or experience of suggestions I'm getting, but I keep coming back to signal interference since this is so clearly related to the locations I am in. {...}

Okay, that's my gain-staging troubleshooting checklist. Time to look for local interference! :D

I'm assuming you don't have an RF scanner, but would you mind sharing the rough locations of your home and shooting location, or even just a list of all the TV stations in the area? Are the two locations very distant from one another?

Digging into the manual, I'm a bit confused because 478.125 isn't listed in Group 01, only in Groups 00 and 15 (and, of course, only for Band TV1417 at that). Especially given that the frequency never changes (which seems unlikely between two different locations; heck, on a lot of wireless gear channel scanning typically produces different results on immediately-subsequent attempts), are you sure you're using the AUTO SET method correctly? Does CLR SCAN produce different results?

Also, for what it's worth, unless you're very sure about which TV channels you want to be operating on, I'd suggest using Group 09 (regardless of which Band you're on), since this will always give you the largest number of multichannel-compatible frequencies to choose/scan from. (Of course, that only matters if the RX is, in fact, choosing frequencies from the Band/Group you've set; the manual does say it's supposed to, but that doesn't seem to be happening here...)

-Russ
Title: Re: Wireless lav audio problems
Post by: Matt Hill on February 08, 2021, 04:42:44 pm
Okay, that's my gain-staging troubleshooting checklist. Time to look for local interference! :D

I'm assuming you don't have an RF scanner, but would you mind sharing the rough locations of your home and shooting location, or even just a list of all the TV stations in the area? Are the two locations very distant from one another?

Digging into the manual, I'm a bit confused because 478.125 isn't listed in Group 01, only in Groups 00 and 15 (and, of course, only for Band TV1417 at that). Especially given that the frequency never changes (which seems unlikely between two different locations; heck, on a lot of wireless gear channel scanning typically produces different results on immediately-subsequent attempts), are you sure you're using the AUTO SET method correctly? Does CLR SCAN produce different results?

Also, for what it's worth, unless you're very sure about which TV channels you want to be operating on, I'd suggest using Group 09 (regardless of which Band you're on), since this will always give you the largest number of multichannel-compatible frequencies to choose/scan from. (Of course, that only matters if the RX is, in fact, choosing frequencies from the Band/Group you've set; the manual does say it's supposed to, but that doesn't seem to be happening here...)

-Russ

Checked on the LED lights - they definitely look like fluorescent, but shut them off anyway and made no difference at all to the problem - thanks for there suggestion though.

Tried using group 9 and re-scanning several times - it does give me different values every time, but never changes the problem. The location of the problem is approx. 1/4 mile from my studio where everything works perfectly. I'm in North Fort Worth, TX, zip code 76244.

There are 2 very large wireless access points in the corners of the library though which were installed in the last 6 months - could these be part of the problem? They were installed across all campuses in our district.

Cisco 9130 AP (https://www.cisco.com/c/en/us/products/collateral/wireless/catalyst-9100ax-access-points/nb-06-cat-9130-ser-ap-ds-cte-en.html)
Title: Re: Wireless lav audio problems
Post by: Keith Broughton on February 08, 2021, 07:21:30 pm


There are 2 very large wireless access points in the corners of the library though which were installed in the last 6 months - could these be part of the problem? They were installed across all campuses in our district.


As far as I understand, these units do not operate in the WiFi band so the access point should not be a problem.
Did you check the RF meters on the receivers with the transmitters off?
Title: Re: Wireless lav audio problems
Post by: Jason Glass on February 08, 2021, 11:43:57 pm
Did you check the RF meters on the receivers with the transmitters off?

Hi Matt,

Keith's question has been asked more than once here, because it's an important one to answer.

Also check the troublesome locations for ultrasonic emitters, which are often used for motion sensing automated energy-saver light switches and security systems.  Although I haven't heard of them specifically causing problems with Sony equipment, they can theoretically wreak havoc on TX companders, and are known to cause issues with some older Wisycom hardware+firmware pilot tone squelch circuits.
Title: Re: Wireless lav audio problems
Post by: Russell Ault on February 09, 2021, 12:08:30 am
{...} Did you check the RF meters on the receivers with the transmitters off?
{...}Keith's question has been asked more than once here, because it's an important one to answer.{...}

+1!

{...} Also check the troublesome locations for ultrasonic emitters, which are often used for motion sensing automated energy-saver light switches and security systems.  Although I haven't heard of them specifically causing problems with Sony equipment, they can theoretically wreak havoc on TX companders, and are known to cause issues with some older Wisycom hardware+firmware pilot tone squelch circuits.

Oooh, that's a nasty one. (Going to add that to my list!) Is this issue closely related enough to "key test" performance to be able to test for it?

-Russ
Title: Re: Wireless lav audio problems
Post by: Jason Glass on February 09, 2021, 12:36:12 am
Oooh, that's a nasty one. (Going to add that to my list!) Is this issue closely related enough to "key test" performance to be able to test for it?

-Russ

It is closely related, but I think we'd need a sustained constant tone to really crush the comp section and disrupt the pilot.  It's ironic that Wisycom's woes with this are the result of a reason they sound so good under most conditions; extended high end.  FWIW, it's only a problem with certain capsules that reproduce significant HF above ~18 kHz (educated guess).  Rumor has it that their latest firmware lowers the front end LPF freq a bit to solve it.
Title: Re: Wireless lav audio problems
Post by: Russell Ault on February 09, 2021, 02:49:43 am
It is closely related, but I think we'd need a sustained constant tone to really crush the comp section and disrupt the pilot.  It's ironic that Wisycom's woes with this are the result of a reason they sound so good under most conditions; extended high end.  FWIW, it's only a problem with certain capsules that reproduce significant HF above ~18 kHz (educated guess).  Rumor has it that their latest firmware lowers the front end LPF freq a bit to solve it.

Makes me wonder how other gear fares against that kind of thing. Of course to test it, the first challenge would be finding a device that can consistently produce those sorts of sustained, constant tones! (I mean, I'm sure Digi-Key has that covered, but I don't think I have anything lying around that'd do the job.)

-Russ
Title: Re: Wireless lav audio problems
Post by: Mac Kerr on February 09, 2021, 09:41:32 am
It is closely related, but I think we'd need a sustained constant tone to really crush the comp section and disrupt the pilot.  It's ironic that Wisycom's woes with this are the result of a reason they sound so good under most conditions; extended high end.  FWIW, it's only a problem with certain capsules that reproduce significant HF above ~18 kHz (educated guess).  Rumor has it that their latest firmware lowers the front end LPF freq a bit to solve it.

We see this all the time where I am currently working. We have hundreds of conference rooms worldwide that we connect to from our NY studio. By default all the installations have the audience reaction system on, which uses an 18k tone to locate users in the room to aim cameras. That tone makes it back to me through the desk mics around the conference table, and they do trigger dynamics processing both in my console and in Zoom. Fortunately my coworker Alex can remote control any system in the corporate network. At this point we have most of them turned off.

Mac
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 09, 2021, 10:31:06 am
Hi Matt,

Keith's question has been asked more than once here, because it's an important one to answer.

Also check the troublesome locations for ultrasonic emitters, which are often used for motion sensing automated energy-saver light switches and security systems.  Although I haven't heard of them specifically causing problems with Sony equipment, they can theoretically wreak havoc on TX companders, and are known to cause issues with some older Wisycom hardware+firmware pilot tone squelch circuits.

In addition to knowing about background RF levels with the transmitters turned off I wonder if
the receiver audio level meters would show the ultrasonic pick up level (if any) with the transmitters
turned on and mics connected.
Title: Re: Wireless lav audio problems
Post by: Matt Hill on February 09, 2021, 03:58:03 pm
In addition to knowing about background RF levels with the transmitters turned off I wonder if
the receiver audio level meters would show the ultrasonic pick up level (if any) with the transmitters
turned on and mics connected.

Sorry I missed the RF meters question - yes, the receiver is showing about 2 bars (out of 6) of activity on the RF meter with the transmitters off. This is the same when at my studio though, which produces great audio.
We definitely have automated energy-saver light switches in most locations including the library in question. We also have them at the studio, but not as many.
Any ideas for fixes or workarounds if this is the problem?
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 09, 2021, 04:15:06 pm
Sorry I missed the RF meters question - yes, the receiver is showing about 2 bars (out of 6) of activity on the RF meter with the transmitters off. This is the same when at my studio though, which produces great audio.
We definitely have automated energy-saver light switches in most locations including the library in question. We also have them at the studio, but not as many.
Any ideas for fixes or workarounds if this is the problem?

We may be getting somewhere.

Does the receiver audio level meters show any level in the library with the transmitters on, mics plugged and with the library quiet?
Title: Re: Wireless lav audio problems
Post by: Matt Hill on February 11, 2021, 11:04:39 am
We may be getting somewhere.

Does the receiver audio level meters show any level in the library with the transmitters on, mics plugged and with the library quiet?

No, none at all...
Title: Re: Wireless lav audio problems
Post by: Mike Caldwell on February 11, 2021, 11:58:44 am
OK.....
Is it possible to power off the access points in the library?

Or for that matter power down the entire library at some time?