ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: Sennheiser EW-D coexisting with EW G3 and G4?  (Read 231 times)

Kevin Maxwell

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1492
Sennheiser EW-D coexisting with EW G3 and G4?
« on: August 07, 2021, 11:30:45 AM »

Sennheiser EW-D coexisting with EW G3 and G4?

A church I am working with wants to add some more Hand Held wireless mics and I am wondering how the  Sennheiser EW-D  will coexist with their EW G3 and G4 systems. I will need to also add and slightly reconfigure their present Sennheiser antenna combiners. They have 3 now and I would like to add 2 more for a total of 5 and use one as the master that feeds the other 4. I think this is what I need to accommodate the receivers and is a little more straight forward then how it is done at the moment.

My concerns are there are 9 Sennheiser wireless mics in their sanctuary and 7 Shure IEM transmitters. All using antenna combiners and distributers with remote antennas on stage. But there are also about 11 other wireless mics in other parts of the building. In the frequency coordination I have 3 backup frequencies for more IEM systems and 4 back up frequencies for wireless mics. But those 4 are split on 2 different bands. But I can probably rearrange some things to make this work but it probably makes more sense to buy the EW-D in those 2 different frequency bands.  Or worse case scenario, do a complete recalculation coordination, which is a real pain in the neck for them because they have to chase down all of the different rooms where the wireless are in use. I think they initially missed some of them the last time we had to do this and they really donít want to have to do that again. Unless it is really necessary.  BTW I am using WWB for frequency coordination and have been for years. And at the moment there isnít a profile for the EW-D in the version that I have which is 6.14.0.186. So can I use the profile for one of the other Sennheiser wireless systems?

It looks like the EW-D would be fine (or should I say fantastic as far as fitting enough in) if it was the only wireless systems in this place but do you use the same criteria for frequency coordination as I would for the analog EW G3 and G4?  And can I use the same antenna combiners?

Then the propagation delay consideration. The path from the Mic to the IEMs is directly to the X32Rack (itís a hard wired split) that acts as the Monitor mixer. I have measured .82ms propagation delay thru an M32 and I think the X32 is very similar. I understand that the EW-D has 1.9ms latency. Now that would mean that there would be about 2.72ms delay thru this setup. I know for most people this isnít a problem for IEMs. But isnít it a problem for some people? I assume we would have to try it (test them) with the different people and see if any of them have a problem. But obviously we wouldnít tell them what we are testing for. I just thought that maybe we should just try inserting a delay and see which people have a problem at what delay times.

Anyone have any comments about these questions and concerns?
Logged

Russell Ault

  • Hero Member
  • *****
  • Online Online
  • Posts: 1379
  • Edmonton, AB
Re: Sennheiser EW-D coexisting with EW G3 and G4?
« Reply #1 on: August 07, 2021, 01:22:06 PM »

{...} I will need to also add and slightly reconfigure their present Sennheiser antenna combiners. They have 3 now and I would like to add 2 more for a total of 5 and use one as the master that feeds the other 4. I think this is what I need to accommodate the receivers and is a little more straight forward then how it is done at the moment. {...}

Hooking up 5 Sennheiser distros in a star pattern like this should work fine, and (depending on the existing configuration) may actually represent an improvement to the RF signal chain (since you can guarantee a maximum of 2 distro amps between antenna and RX, which is what those distros are spec'ed for).

{...} it probably makes more sense to buy the EW-D in those 2 different frequency bands.  Or worse case scenario, do a complete recalculation coordination, {...}

I would strongly suggest doing whatever you need to do to keep all the EW-D in the same band, at least for now. Especially if you're only talking about a couple of channels (that won't talk to anything else you already have), having everything in one band gives you the flexibility to move equipment around easily (e.g. if a TX breaks all the other TXs in the building are eligible as spares).

{...} BTW I am using WWB for frequency coordination and have been for years. And at the moment there isn’t a profile for the EW-D in the version that I have which is 6.14.0.186. So can I use the profile for one of the other Sennheiser wireless systems? {...}

The frequency charts for the EW-D look very strange to the uninitiated (e.g. this is for the Q1-6 range) because the channels are spaced evenly at 600 kHz intervals (SLX-D, for comparison, randomizes the spacing slightly). This is very, very different from the spacing used for analogue wireless (where evenly-spaced frequencies guarantees 2T3O intermod products will land on your other assigned frequencies). With the caveat that I haven't had to coordinate any EW-D systems yet, here's what I would do:

In WWB I would pretend that the EW-Ds are actually SLX-Ds and add devices accordingly. Then, I would find a chunk of empty spectrum that's at least 600 kHz ◊ ( number of channels + future room for expansion/spares ) and manually assign frequencies to the "SLX-Ds" in evenly-spaced 600 kHz intervals (since calculated frequencies that will work for SLX-D might be too close for EW-D). Then I'd (re-)build the rest of the coordination around that. Using WWB's "Inclusion List" feature to break the spectrum into blocks and keep like-with-like can make this (and future re-coordinations) easier.

{...} And can I use the same antenna combiners? {...}

I asked a similar question on here a few years ago. In a nutshell, RF is RF, and for our purposes the distro doesn't care if the signals passing through it are analogue or digital.

{...} Then the propagation delay consideration. The path from the Mic to the IEMs is directly to the X32Rack (it’s a hard wired split) that acts as the Monitor mixer. I have measured .82ms propagation delay thru an M32 and I think the X32 is very similar. I understand that the EW-D has 1.9ms latency. Now that would mean that there would be about 2.72ms delay thru this setup. I know for most people this isn’t a problem for IEMs. But isn’t it a problem for some people? I assume we would have to try it (test them) with the different people and see if any of them have a problem. But obviously we wouldn’t tell them what we are testing for. I just thought that maybe we should just try inserting a delay and see which people have a problem at what delay times. {...}

I'll have to see if I can dig up some of the studies that were done on IEM latency budget. If I remember correctly, the general rule of thumb is that most people are unaffected by IEM latencies of up to 10 ms, but as you mentioned there are exceptions (particularly, I seem to recall, violin players). Personally, in the sub-3 ms range I wouldn't be too concerned; my own experience with a similar setup undergoing an analogue-to-digital transition (but with QLXD and therefore almost a whole extra ms) was that it was a total non-issue for the singers involved. Especially since you'll still have a lot of analogue RF floating around, my suggestion would be to just do the swap and then, on the off-chance someone does have a problem, be prepared to swap them back.

The other thing to be aware with digital wireless latency is that any source being picked up by equally by both analogue and digital wireless will mix into a comb filter because of the time offset. This is probably a total non-issue for handheld mics, but might preset some weirdness for lavs and theatrical use. Compensating for the delay on the analogue channels should sort this out.

-Russ
« Last Edit: August 07, 2021, 01:24:53 PM by Russell Ault »
Logged

Scott Helmke

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1782
Re: Sennheiser EW-D coexisting with EW G3 and G4?
« Reply #2 on: August 07, 2021, 02:35:19 PM »

Without getting too technical (partly because I'm not qualified for that!), the RF signal from a digital wireless system is basically an analog signal.  What's mostly different is that the the modulated signal just looks like a solid block of noise instead of a spike that's wiggling around. 

Remember modem noise when you had to dial in to the internet?  Same thing, it's a scheme to pack absolutely as much info as possible into a limited channel.

I'd second the recommendation to just substitute SLX-D for EW-D in the short term, it should be close enough.

You're using zones in WWB for all the different rooms, right?
Logged

Kevin Maxwell

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1492
Re: Sennheiser EW-D coexisting with EW G3 and G4?
« Reply #3 on: August 07, 2021, 04:26:58 PM »

Without getting too technical (partly because I'm not qualified for that!), the RF signal from a digital wireless system is basically an analog signal.  What's mostly different is that the the modulated signal just looks like a solid block of noise instead of a spike that's wiggling around. 

Remember modem noise when you had to dial in to the internet?  Same thing, it's a scheme to pack absolutely as much info as possible into a limited channel.

I'd second the recommendation to just substitute SLX-D for EW-D in the short term, it should be close enough.

You're using zones in WWB for all the different rooms, right?

I am not using different zones for the different rooms because the other rooms are under the sanctuary so they are on top of each other.
Logged

Scott Helmke

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1782
Re: Sennheiser EW-D coexisting with EW G3 and G4?
« Reply #4 on: August 09, 2021, 09:01:35 AM »

I am not using different zones for the different rooms because the other rooms are under the sanctuary so they are on top of each other.

If you're running short of space, I'd recommend trying it.  Intermod really only becomes significant when transmitters are close together - even a wall/floor and a few feet of separation can make all the difference in the world.
Logged

ProSoundWeb Community

Re: Sennheiser EW-D coexisting with EW G3 and G4?
¬ę Reply #4 on: August 09, 2021, 09:01:35 AM ¬Ľ


Pages: [1]   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.026 seconds with 21 queries.