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[Lou Paris (Paris Creative)]

For the past few years I have been getting more and more requests for complex ceremony and reception services requiring additional wireless options. In my arsenal I have:

A 4-mic "pack" of Senn EW100 G3 receivers + ASA1 splitter (a band)
A 2-mic "pack" of Senn EW100 G3 receivers with no splitter (a band)
A Senn EW300 IEM G3 receiver + Soundcraft Ui24 mixer in a "mixer box" (x2) (g band)

A few times this year now I have had the need to use all six mics simultaneously + IEM to capture audio, record (2-track and multi-track) and also broadcast out to battery-powered speakers (Maui 5 Go) for ceremonies. I've also had 5-6 mics for reception live performances a couple of times this year.

Naturally, with more mics in play, and my IEM, there is always the potential for intermodulation and other anomalies to interfere. While Senn is good to build in their banks intermodulation-free frequencies I still see, on some occasions, random interference when I tune into a scanned channel that should be clear. I have not had a mic drop-out in all these occasions but I know that with more mics in play I am playing with potential disaster.

So I am contemplating what my next steps should be. I could invest in something like a RackPRO analyzer but that is a more manual aspect to do true frequency coordination. I could invest in something like the ULXD4Q + PSM900 and WWB, but of course that is a chunk of change not only swapping out my core handhelds and body packs, but also my lavs and over-the-ear mics. But maybe it's worth it in the end when it comes to piece of mind & time savings.

I wonder what that threshold of relying upon basic hardware scans (which again I have not had a failure yet) and getting into more serious frequency coordination.

[Jordan Wolf]

Lou,

An onsite RF scan will tell you a lot about where you should be placing your frequencies. There is a lot of movement of Digital TV stations at the moment, so what once was open may no ponger be (and vice-versa).

The RF Explorer handheld units have worked well for me, and I think when you combine then with RF best practices and software coordination, you get very usable information.

I try to keep a safety gap between my wireless microphone and IEM frequencies. Physically separating the antennas and using their characteristics so they don’t interfere with each orher is important as well.

The recent update to Shure’s Wireless Workbench 6 has made it even more capable, and Sennheiser models are baked into the software already.

[Henry Cohen]

For the past few years I have been getting more and more requests for complex ceremony and reception services requiring additional wireless options. In my arsenal I have: . . .

There's no specific RF channel count threshold as to when to get some sort of spectrum analyzer; it's based on workflow, required system operation performance and reliability, RF environment and comfort level. The simple answer is that with the cost of even the most rudimentary analyzer (the RF Explorer) at less than a cheap channel of wireless mic, and many mid tier offerings (new and used) at less than $1k, there's no reason not to have this valuable tool if your show and reputation are at all important. Not being able to comprehsively "see" the RF environment given the TV repack, co-channel RF mic/com/IFB/IEM users, TVBD/WSD's and unintentional radiators of noise, is a path to failure.

Understanding the RF environment however is only one important aspect to a successful wireless deployment. Another critical matter is deploying your equipment in an optimum manner:
- Start with proper band planning and then frequency coordination;
- Get all antennas up high, above head height and any other obstructions;
- Use appropriate antennas, directional or omni-directional;
- Use a double shielded (low loss) coax of appropriate size given length, and ensure the coax is actually in good condition;
- Keep IEM/IFB transmit antennas away from, and not point at if directional, mic receive antennas.
- Keep overall RF gain structure from the antenna to the receiver as close to unity as possible;
- Avoid the use of RF amplifiers / pre-amplifiers;
- Use proper combining of IEM/IFB transmitters to a single antenna, or keep the individual TX antennas sufficiently separated from each other (and the RX antennas).

Having your mics in the A band and the IEMs in G, is a good start; try to keep at least 4MHz between the lowest IEM and the highest mic frequencies, the greater the separation the better.

[Lou Paris (Paris Creative)]

Lou,

An onsite RF scan will tell you a lot about where you should be placing your frequencies. There is a lot of movement of Digital TV stations at the moment, so what once was open may no ponger be (and vice-versa).

The RF Explorer handheld units have worked well for me, and I think when you combine then with RF best practices and software coordination, you get very usable information.

I should have mentioned I do have a RF Explorer handheld that I fire up to ensure that nothing will accidentally stomp over my broadcasts. [/quote]

My current workflow is as follows:

a) Prelim research in the area I am operating out of just so I am aware of what frequencies should be in use from the info that I have. Of course, repacks are going to make things more interesting since the data out there is so haphazardly put together. Luckily I am 40+ air miles away from the larger metro areas (Albany and NYC) so I am dealing with smaller overall counts to deal with. I operate in a typical 60 mile radius so I could always be closer to these metro markets.

b) Prelim scan with my Senn to see where it thinks things should be placed.

c) Fire up my RF explorer and double-check where things landed on, ensuring that is the cleanest signal to be working on and cross-check my original analysis.

I separate out my IEM operation as far as I can frequency wise. I also have my IEM and in my Mics in separate cases to rule out any carryover of signal on the chassis or ground plane. In many cases (but not all) I use my RF Explorer diversity fin to isolate my signals to my operational area.

The best I could do with my current equipment at this point would be some type of ISA and then manually plug in my values which of course cost some time. Now is the debate if I should go beyond that, go with more networkable devices that can be centrally managed and give me more piece of mind.

[Luke Geis]

If you don't have an antenna distribution system, you will be limited. You will want to find a way to get all the wireless units into a single distribution amp in one way or another. You may have to split or why a couple of the units. Which is what may have you desiring to go with a different system altogether.

Wireless is fickle and you have to follow some rules to give it the best odds of working 100% every time. Line of sight is usually problem #1. With weddings, they don't want to know you exist, so it makes it tough to place your wireless units or antennas in the best possible place. Getting a direct line of sight is imperative at the very least. Next is the distance. Most lower-end RF units are not really optimized for distance and it doesn't help when you have a stack of RF units with their antennas pointing all over the place. This is where an Antenna distribution amp will help greatly. It combines all the units into a single pair of antennas and because most DA's are active, they improve reception strength and therefore distance capability. 

The biggest caveat is that RF loses more power in the air than it does down a cable. So it is beneficial to get the antennas as close as is practical to the transmitters. The closer you can get the antennas to the transmitters the higher the odds that the receiver will only hear the transmitters. So getting longer 50' to 100' 50ohm BNC cable is a great way to get your antennas closer to the officiant and the bridal party. Another thing is that wireless does not like boundaries or cages. So getting the antennas up in the air is ideal. Most people believe that they need to place the antennas around on either side of a stage or area which is not exactly true or needed. Often times you only need to place the antennas about 2' - 4' apart and they will be far enough apart to not bother each other. Actually having them too far apart can be worse than good. So you don't have to go crazy trying to get the antennas separated by much, juts get them up and as near as practical to the where the Transmitters are. 

[Dave Garoutte]

A 4-mic "pack" of Senn EW100 G3 receivers + ASA1 splitter (a band)
A 2-mic "pack" of Senn EW100 G3 receivers with no splitter (a band)
A Senn EW300 IEM G3 receiver + Soundcraft Ui24 mixer in a "mixer box" (x2) (g band)

You can add another ASA1 to the 2-mic pack and daisy chain the the ASAs to use one antenna set for all 6 (up to receivers.

[John Sulek]

This is where an Antenna distribution amp will help greatly. It combines all the units into a single pair of antennas and because most DA's are active, they improve reception strength and therefore distance capability. 

In my understanding (always standing by to be corrected by those more knowledgable), the active portion of the rx DA is there to overcome the losses in the passive combining network and restore the overall gain closer to unity.
There are very few instances where you need active gain on the rx antennae....most often to overcome a very long cable run.
Sorry for the swerve, but this "active is better on rx" thinking drives me a bit crazy. It causes far more problems than it solves in most cases. Better coax and antenna choice/placement is a path less fraught with unintended consequences.
Safe travels everyone!

[Luke Geis]

It's a two-way street I think. Too much antenna gain is a bad thing. As I mentioned in my post, longer cable and having the antenna closer to the transmitter is better than the time of flight in the air. Cable length does = loss and active antennas recover that loss. You can also add gain for scenarios where the transmitters are 300' away.

Ultimately the goal is to have the receiver hear as little of anything as possible with the exception of the desired transmitter. You want the lowest noise floor with the highest signal to noise ratio in favor of the transmitter. Many active antennas distros have gain reduction as well in order to deal with the added gain that the antenna paddle provides.

I feel an active system is a more prudent choice as a single purchase simply because MOST can deal with every situation whereas as a passive system may not. The hardest part about RF is understanding that it isn't about antenna gain, it is about the signal to noise ratio. Most don't afford $10 per foot cable and don't replace it every time it is bent too far or even regularly. Most people get basic cable and use it till an end falls off. This can be long after the cable has been far out of spec.

[Scott Holtzman]

In my understanding (always standing by to be corrected by those more knowledgable), the active portion of the rx DA is there to overcome the losses in the passive combining network and restore the overall gain closer to unity.
There are very few instances where you need active gain on the rx antennae....most often to overcome a very long cable run.
Sorry for the swerve, but this "active is better on rx" thinking drives me a bit crazy. It causes far more problems than it solves in most cases. Better coax and antenna choice/placement is a path less fraught with unintended consequences.
Safe travels everyone!

This is correct, the front end of the RX's have plenty of low noise gain.  Any amplification prior to the RX "front end" filtration amplifies the noise and the signal.  You get no gain in S/N ratio.

The amp in a multicoupler is to overcome coupling losses.   The gain is adjustable in some of them for different configurations. 

[ProSoundWeb Community]