First off, you need to get a frequency coordination for your area. This is very important as it will tell you what channels it is likely you can operate on. You can use the 15-day evaluation of IAS to do that for you (
IAS - Intermodulation Analysis System) or you can also contact most dealers and they can do it for you.
I agree. Frequency Coordination is very important. For your needs, the demo of IAS will work fine, so don't buy it. Feel free to PM me if you are unsure how to do it.
Keep in mind that if you go running multiple channels you really need to consider an antenna distribution
system. Some receivers (Lectro
Venue) have a sort of distribution built in to the chassis while most others will require an antenna splitter of some kind.
Agree once again, but read my blog post on this topic:
Do Multicouplers (Antenna Distros) Prevent Intermod? « Mike Benonis
It's something to factor into the cost of your
system.
If you are talking about TV band analog
UHF wireless 8 years in the future could be a very difficult place to be. For right now forget about brands and think about what it will take to operate in that band. On Jan 13th of this year a new FCC rule went into
effect that allows "Super-Wi-Fi" to operate in all
open white space with the exception of two "protected" channels. The protected channels (not yet officially assigned) will generally be the nearest unoccupied channels nearest
channel 37. So if you are not in a major metro area that will be
channel 36 and
channel 38.
This is true, but technically speaking. The reality of the situation is far more complex than this makes it sound. If you design your wireless mic
system correctly, you won't be facing such a huge problem, now or in the future. I believe I've posted on this before but I'd be glad to elaborate. It basically boils down to proper antenna placement.
I don't believe you can currently buy any brand of wireless that can operate on these channels that will cost you less than $1000.
I'd trust an Evolution 100 series. Not so much the
Shure SLX. But it can be done for less than $1000.
If you do not operate on protected channels than you will likely
face some very stiff RF competition from unlicensed consumer devices (think smart/
cell phone type service). When enough of your audience has these devices in their pockets they will likely cause
conventional analog wireless to become so problematic that you won't want to use it.
My field tests (unpublished at the moment, but coming out in the future) show that it's only a significant problem if a white space device is in the
house, and the antennas are behind the audience. And: the devices are operating co-channel. But, the wireless mics will also jam the WSD's pretty effectively and so they will probably find a different
channel to operate on.
Also look up the "National Broadband Plan". The FCC is on
track to remove over half of the currently available operating space by 2015.
The Broadband plan is not a Notice of Proposed Rulemaking, and definitely not a Report and Order. We shall see what happens, and you can also file comments if you are so moved to do so.
About the only way to insure that you will have wireless that will operate in 8 years is to move to a technology that does not operate in the TV bands. Currently there is gear available from
Shure, Sabine, Lectrosonics and my company
Line 6. I invite you to do a little investigation into these products.
2.4 GHz may be a viable option if you do your antennas right, once again. Wi-Fi and other devices are definitely a problem though. Not sure if anyone makes mics that work between 902 and 928 MHz, but that may work too.
DO NOT, UNDER ANY CIRCUMSTANCE, BUY MICS THAT OPERATE BETWEEN 944 AND 952 MHz!!! These mics have the potential to take radio stations off the air and you WILL get slapped with a > $10k fine by the FCC when that station's engineer tracks you down. And he will.
Also, I don't think the white space devices will be a huge deal -- Last I heard the FCC was requiring that they not interfere with wireless
microphone operation. I don't know how that will or will not work - but at least in the TV band I have some idea about what interference I'm going to have (TV stations) rather than wondering if "Joe audience member" is going to turn on his wifi enabled bluetooth phone during my show and cause
channel 7 to stop working".
The FCC is protecting wireless microphones in two ways. First, you may operate in the two protected channels on either side of
Channel 37. You will be able to know what these channels are after the White Space databases go live, but you can guess pretty well now by which TV channels are unoccupied in the vicinity. Second, if you pack 8 mics in each
channel (read: you are using > 16 channels), you may apply for protection in other channels and WSDs will be blocked from operating there.
Broadcasters can also get a licence, but you can't. These rules may change down the
road, BTW.
Plus with devices operating in the TV band -- one solution (I would think -- I'm no audio engineer) is to move the receivers/antenna closer to the
stage. It would seem to me that if the antenna are direction and closer to the
stage AND the belt packs where putting out more
power than the white space device (which I would assume it would) would mean that you could
block out or at least get rid of some of the noise.
This is essentially right. In my experience, Wireless Mics need about 12 dB of SNR. So the received wireless mic signal needs to be 12 dB greater than the received WSD signal, on the same
channel. With good antenna placement using directional antennas, you can EASILY achieve this.
I'm turning into ship, I think...scary.