WWB6/ULX-D RF power setting?

[Jay Ashworth]

I noted that on the monitor "tab" of WWB6, it showed all 12 of my active ULX-D packs at "Low RF Power". A few of them dropped out unexpectedly while offstage in the dressing rooms (ironically; closer to my racks). So I assumed it mattered.

So I poked around found that setting in the IR Sync tab of Device Properties, and I set it to Normal RF Power, and then resynced and even power-cycled a couple packs... and it still says "Low RF Power" (note: not "signal"; that's around -70dBm from the meter).

I checked the Properties dialog, and "Normal" stuck, there.

Is there something else I'm supposed to be doing here?

 

[Jay Ashworth]

I have, for what it's worth, located this knob in the pack menu, and turned them all up, but it'd still be interesting to know if I'm misinterpreting what's supposed to happen there...

 

[mbenonis]

Hey @Jay Ashworth, This should work as you described above. Set the IR Preset for RF Power to "Normal" and click Apply below (this part is important). Then sync to the same channel you set that on, and the pack will change RF power. Do make sure everything is on the latest version/firmware (WWB 6.14; ULX-D RX 2.4.9, ULX-D TX 2.4.13).

 

[Jay Ashworth]

Hey @Jay Ashworth, This should work as you described above. Set the IR Preset for RF Power to "Normal" and click Apply below (this part is important). Then sync to the same channel you set that on, and the pack will change RF power. Do make sure everything is on the latest version/firmware (WWB 6.14; ULX-D RX 2.4.9, ULX-D TX 2.4.13).

Well, that is what I would have expected, but it wasn't what I got. I'm back in the room tomorrow, I'll try it again with some other easy to spot setting. In fact, I have two spare packs in the booth and I guess I could try it with those.

I just downloaded this copy of WWB, but I have not upgraded the firmware on the packs or the receivers since we got them last year. I guess I'm going to have to go figure out how you upgrade the firmware on the packs, since I don't have any drop-ins.

 

[TimMc]

You will need this:

SUU - Shure Update Utility

Easy-to-use and free-to-download, the Shure Update Utility helps you update firmware on firmware on compatible Shure products.

www.shure.com

 

[Jay Ashworth]

I flipped through that page, Tim, and it doesn't really seem to say how you update packs, either; I assume you do not do it through a receiver IR link...?

 

[rphilip]

I flipped through that page, Tim, and it doesn't really seem to say how you update packs, either; I assume you do not do it through a receiver IR link...?

Update the RX and then update the TX via IR, it takes a bit longer than a frequency sync but still less than a minute if I recall right.

 

[Jay Ashworth]

Oh, it really *does* update the TX through the IR?

Ok. I'll dive in, then. Strike day.

 

[mbenonis]

Yes, sorry I wasn't clear--even the FW update is via IR!

 

[TimMc]

Mike beat me to it - yep, the update is via the IR port. Been a while since I've done it, but IIRC it took about 30 seconds per transmitter; I was expecting much longer. Also IIRC, update the receivers first.

 

[Jay Ashworth]

Can anyone comment on how tightly the RX and pack FW needs to be matched for everything not to go to hell?

 

[mbenonis]

@Jay Ashworth It depends. I would recommend they all be on the latest firmware. Definitely do not mix 1.x and 2.x. If updating from 1.5.6 or earlier, call Applications Engineering for an assisted update...don't attempt it yourself.

 

[JJBerman]

Can anyone comment on how tightly the RX and pack FW needs to be matched for everything not to go to hell?

When I was updating back last December or August 2019 I saw something that was saying keep the first 2 digits of the version the same, so "M.m.p.b" the M.m. needed to be the same where the .p.b was a 'little' more flexible.

When I was updating 24 packs & 8 Handhelds, I setup a jig to update 2 units at once, then I just swapped back and forth between the jig updating 1 pack at a time.
The time it took me to remove batteries from freshly updated pack, install batteries and power next pack on, and set it in the jig took the amount of time for the pack already on the jig to update.

My receivers are in a wall mount rack, so for my jig, I setup 2 mic stands with handheld clips and balanced the packs on the clips. The entire process from setup to tear down took me like 20min.
It took longer for me to read and double check that I had the proper firmware to update and read most of the release notes.

 

[donboomer]

Do remember that wireless mic/ear systems work best TOGETHER at the lowest power levels that will work in a situation. So you want to avoid turning up the Tx power if it is not necessary. When you are getting drops backstage and in dressing rooms I’m imagining you are no longer in line of sight of your antennas. So boosting power may get you on back there at the expense of reduced reliability out on your stage. The more power, the more IM produced. For every 1dB of increased power you get a 3dB boost in the amount of IM created.

 

[mbenonis]

This FAQ talks about this issue in-depth:

https://service.shure.com/s/article/interaction-of-psm-transmitter-and-wireless-mic-receiver

 

[FMEng]

Do remember that wireless mic/ear systems work best TOGETHER at the lowest power levels that will work in a situation. So you want to avoid turning up the Tx power if it is not necessary. When you are getting drops backstage and in dressing rooms I’m imagining you are no longer in line of sight of your antennas. So boosting power may get you on back there at the expense of reduced reliability out on your stage. The more power, the more IM produced. For every 1dB of increased power you get a 3dB boost in the amount of IM created.

That's certainly true in theory, but one of the claims for ULXD and QLXD is that the final RF stage is less prone to generating intermod products. It isn't class C, like most analog transmitters. I recall Shure demonstrating the trait on a spectrum analyzer in one of their marketing videos.

 

[mbenonis]

That's certainly true in theory, but one of the claims for ULXD and QLXD is that the final RF stage is less prone to generating intermod products. It isn't class C, like most analog transmitters. I recall Shure demonstrating the trait on a spectrum analyzer in one of their marketing videos.

This is correct--the Shure digital power amplifiers in the transmitters are less prone to intermod. Nonetheless, this doesn't really affect intermod between an IEM transmitter and a receiver, as it's pretty rare to have enough signal strength from the IEM transmitter at the wireless mic to cause intermod.

 

[TimMc]

Digital modulation schemes used in these devices do not 'suffer' from IM in the same way that analog FM does. The physics of 2 carriers combining to create an intermod product still exists; it's that the result is not devastating effects on the desired audio signal from another digital RF audio device.

Remember that just because the IM doesn't bite *your* ass does not mean you are not creating spurious emissions.

 

[mbenonis]

Digital modulation schemes used in these devices do not 'suffer' from IM in the same way that analog FM does. The physics of 2 carriers combining to create an intermod product still exists; it's that the result is not devastating effects on the desired audio signal from another digital RF audio device.

Remember that just because the IM doesn't bite *your* ass does not mean you are not creating spurious emissions.

There are some shades of gray where which depend on what intermod you are referring to. I believe in this case, you may be referring to intermod generates by two digital transmitters, both of which have linear power amplifiers. In this case, the intermod products are of far lower amplitude than with equivalent FM transmitters with Class C amplifiers. However, an overloaded receiver preamplifier (say, from two nearby 100 mW analog IEM transmitters) can still have a devastating effect on wireless mic reception for the same reasons as with older wireless mics (it throws a hot carrier on top of a wireless mic, and also desensitizes the receiver).

The key is to separate any TX and RX sources as much as possible, and use to use a tool like IAS or WWB to coordinate frequencies using appropriate profiles.

 

[donboomer]

Digital modulation schemes used in these devices do not 'suffer' from IM in the same way that analog FM does. The physics of 2 carriers combining to create an intermod product still exists; it's that the result is not devastating effects on the desired audio signal from another digital RF audio device.

Remember that just because the IM doesn't bite *your* ass does not mean you are not creating spurious emissions.

Agreed!

But I think we've drifted a bit off topic which was when I wander off stage ... So if anyone is still interested in that maybe this will help -

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As far as IM, digital or otherwise ... the less of it you have the more open spaces you will have to be able to assign mics and ears to. Here's a sensible approach to getting mics and ears to play nice together - https://www.rfvenue.com/blog/successfully-running-mics-and-ears-together