# Wireless Mic Hunting



## martyclynch (Mar 1, 2011)

Here is the scoop:

We are a small College with a small but stable annual budget. We will never be able to afford a full sound overhaul but we can slowly build up a decent stock of equipment if we do it correctly. We have good amplifiers and sufficient speakers that more than fill out our revamped gymnasium. We would also like to make a small musical a part of our annual season.

I want to purchase wireless microphones, but I have to do it one at a time each year. If you have any suggestions, I am looking for the microphone that will be reliable and of decent quality (doesn't need to be stellar in this space, but I don't want a piece of junk either). It would be safe to say that we can set aside roughly $500 a year for one microphone, so I would love to find one that will last 8 years or more before I need to replace it. We will use them lightly and occasionally so I think that should not be too difficult.

More than anything I would like to purchase the same microphone each year so I can avoid the issues that come with multiple brands (I am not thinking of technical issues). That is why I am looking for advice. I saw the Audio-Technica BP 893 MicroEarset and thought it might be suitable. Any comments?


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## lparks1 (Mar 1, 2011)

I'm not expert by any means, and wireless is still somewhat new territory for me as well - but I do know enough to make some general suggestions:
> 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.

> 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.

> At your price range ($500) - You could afford several different brands that should get you enough usable channels. In the Sennheiser Arena, you might want to look at the EW-100 G3 series. They start at around $499 for a receiver and transmitter without microphone. In the Shure Arena, you might look at the SLX series - Again, they start at about $500 for a receiver/transmitter without mic. There is also the Audio Technica 3000 series which is a little cheaper ($300 for a receiver/transmitter without mic from Northern Sound and Light).

Each one of these are on a similar "plane" to each other. Some offer different features that others don't however - and I would suggest exploring around more information about each of the systems I have mentioned to see what would and would not work for you. 

Personally, if you only plan to expand to maybe 8 receiver/transmitters - then I would look at the Audio Technica 3000 series. They currently operate in 3, 25MHz bands and should provide more than enough usable channels across those bands in your area to get 8 units together - and they are about $200 less than the other guys. AGAIN, this is not including elements or a distribution system once you start running more than a few channels.


martyclynch said:


> Here is the scoop:
> 
> We are a small College with a small but stable annual budget. We will never be able to afford a full sound overhaul but we can slowly build up a decent stock of equipment if we do it correctly. We have good amplifiers and sufficient speakers that more than fill out our revamped gymnasium. We would also like to make a small musical a part of our annual season.
> 
> ...


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## dboomer (Mar 1, 2011)

*Re: Wireless Mic Hunting - the future*


martyclynch said:


> Here is the scoop:
> 
> I would love to find one that will last 8 years or more before I need to replace it. We will use them lightly and occasionally so I think that should not be too difficult.



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. 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. 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.

Also look up the "National Broadband Plan". The FCC is on track to remove over half of the currently available operating space by 2015.

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.

Don Boomer
Wireless Sales Engineer
Line 6, Inc.


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## lparks1 (Mar 1, 2011)

While I agree with Don Boomer on the fact that you cannot really tell where the TV band will be in 8 years -- I do not agree that your only option to is look outside the TV band. The only option outside the TV band right now is Wifi (2.4GHz). The problem with Wifi band is that every device imaginable (from the microwave in the green room to the punter with his handset in the audiences) are likely causes of interference. That is the problem with a purely unregulated band -- is that who knows what you'll run into. 

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".

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.

Now if the FCC does allow white space devices to operate over Wireless mic's or the technology they put in place for it fails -- then we really are screwed in terms of operating wireless mic's unless someone can come up with a new band to operate in. Frankly, I don't see why technology has taken this long to "invent" a new safe band for Wireless Mic's that wont compete with TV and internet signals. 

Yes, I am going to use the age old adage: We can send a man to the moon.... but we can't...... year you get it.

Just my $0.23 worth.


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## museav (Mar 1, 2011)

No RF spectrum is sacred or not subject to change and the reality is that while a particular model may be available for years, between potential RF spectrum reallocations, market changes, the need to come out with 'new' products, etc., I wouldn't count on any specific model being available for more than a couple of years.

I also think that the two 'safe harbor' channels that Don noted and that the FCC committed to for wireless microphones and IEMs are the best option for many people for the foreseeable future, but between the slow adoption of TVBDs and no other immediate changes occurring in the UHF spectrum, finalizing this aspect as well as the database for TVBDs seems to be going very slowly.

You might also consider that if you have multiple receivers you might soon want to include some form of antenna distribution and some remote antennas, which could affect your spending plans.


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## mbenonis (Mar 1, 2011)

lparks1 said:


> 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.


lparks1 said:


> 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.


dboomer said:


> 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.


dboomer said:


> 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.


dboomer said:


> 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.


dboomer said:


> 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.


dboomer said:


> 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.


lparks1 said:


> 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.


lparks1 said:


> 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.


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## bishopthomas (Mar 1, 2011)

mbenonis said:


> I'm turning into ship, I think...scary.


 
No way. Write an essay without punctuation and verbs and then you're turning into Ship.


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## lparks1 (Mar 1, 2011)

Yes, the Sabin Wireless SWM series operates between 902 - 928Mhz as well as 2.4GHz.
http://www.sabine.com/resources/SWM7000/Literature/SWM7000-6000%20Brochure%20090110.pdf

Only problem with these are that there is a maximum of 32 channels available to use considering no other interference. The 2.4GHz model has a supposed 70 channels with no interference. While Sabine might be a great wireless system, I find it hard to justify the cost of the receiver when I can buy a comparable Lectronsonic Venue for the pretty close to the same price (even cheaper if you sub the Lectro body-packs for some other brand)


mbenonis said:


> 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.


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## BillESC (Mar 1, 2011)

My preference is the Audio Technica 3000 series along with proper antenna placement. They've never let me down. Available below the published MAP price of $ 499.00, you'd be able to buy your third mic and an antenna distribution system on year three.


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## waynehoskins (Mar 1, 2011)

The state of wireless microphones right now is such that to do a "medium-scale" deployment -- more than, say, 6 or 8 radios -- you really ought to know what you're doing RF-wise, especially if you're in a metro area. In metro areas, there are virtually no vacant channels at all, so you have to stay on top of what TV stations are increasing power or changing antenna patterns because you will be co-channel with them.

With a few radios, you may be able to get by on luck. When we first got an IEM kit at the church a few years ago, I hadn't done any research, just put it on the air and it worked, except it was spotty. There were spots where it dropped out. As it turns out, that IEM was co-channel with the NBC station's DTV transmitter (during the Transition), and moving up the band about 20 megs cleared it right up.

In the Dallas area where I am, I know of three vacant channels in UHF TV band: two guard channels around the land mobile allocation, and one all by itself. I did a quick prediction for somebody a few months ago, I forget where, in a rural area; all their UHF TV spectrum was vacant except for one channel. That's a pipedream in the metro areas.

I say all that to say this: getting wireless is a good thing, but I'd stop at a small number like 4. With that, you don't have near as much self-coordination homework to do. When you need more than 4, for musicals, rent. Unless you're doing many musicals a year, it's far easier that way, to hire a soundco to provide and coordinate the RF gear you need. They'll have a better feel for the RF landscape and can fix problems. I guess that presumes you're in a metro area; if you're rural, it may be harder to find one.

For what to buy, I'm impressed with Sennheiser's Evolution G3 radios. I've liked the Evolution Wireless from the start, but the third generation adds two very useful things to me: on-channel telemetry (battery level) and with their multicouplers, power distribution over coax.


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## lparks1 (Mar 2, 2011)

What devices operate in the 915MHz band anyway? I mean, if the Sabine now has the option for that frequency range, it might just work for some users more than the 2.4GHz band. 

I know some cordless phones operate in that band -- but I don't think Wifi or Bluetooth does, which IMHO are probably the biggest interference culprits in the 2.4 band. 

Options? Thoughts? Sabin actually has a very cheap SWM-4000 that offers 4 receivers in the 915MHz band for $739, which is roughly less than $200 a channel. This alone scares me some-what, but it might be a good alternative for those needing only a few channels or those that otherwise would be stuck with some NADY crap.


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## mbenonis (Mar 2, 2011)

lparks1 said:


> What devices operate in the 915MHz band anyway? I mean, if the Sabine now has the option for that frequency range, it might just work for some users more than the 2.4GHz band.
> 
> I know some cordless phones operate in that band -- but I don't think Wifi or Bluetooth does, which IMHO are probably the biggest interference culprits in the 2.4 band.
> 
> Options? Thoughts? Sabin actually has a very cheap SWM-4000 that offers 4 receivers in the 915MHz band for $739, which is roughly less than $200 a channel. This alone scares me some-what, but it might be a good alternative for those needing only a few channels or those that otherwise would be stuck with some NADY crap.



A quick check of the FCC's ULS (http://wireless.fcc.gov/uls) shows a ton of radiolocation in the band, and don't forget about baby monitors and cordless phones. Also, it's allocated to the Amateur Radio service, and ham's can run as much power as they want up to 1.5 kW. So you could in theory find TV stations and other ham stuff.

Not to say it's going to be there in your area though.


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## waynehoskins (Mar 2, 2011)

It occurred to me last night that one of the things that makes TV Band so attractive is that it's highly predictable. Frequency assignments, power, and pattern are well-documented and published for the stations that interfere with us, and they're on the air continuously. The RF landscape is the same this morning at 10 as it was last night at 8, and most likely the same as two weeks ago.

We run milliwatt radios, and full-power TV stations use megawatt transmitters.

The ugly thing about 902 and 2.4 gigs is their unpredictable nature. While the megawatt stations are gone, there are kilowatt stations that are sporadic in operation, as well as cordless phones and wifi radios and such. A frequency may be clear for days, weeks, at a time, but an interfering station may come on the air at the worst possible time in your show, and disappear again after a minute or two.


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## chausman (Mar 3, 2011)

waynehoskins said:


> It occurred to me last night that one of the things that makes TV Band so attractive is that it's highly predictable. Frequency assignments, power, and pattern are well-documented and published for the stations that interfere with us, and they're on the air continuously. The RF landscape is the same this morning at 10 as it was last night at 8, and most likely the same as two weeks ago.
> 
> We run milliwatt radios, and full-power TV stations use megawatt transmitters.
> 
> The ugly thing about 902 and 2.4 gigs is their unpredictable nature. While the megawatt stations are gone, there are kilowatt stations that are sporadic in operation, as well as cordless phones and wifi radios and such. A frequency may be clear for days, weeks, at a time, but an interfering station may come on the air at the worst possible time in your show, and disappear again after a minute or two.


 
We just need our own little area where we (People using W/l mics) can do what we wnat and no one except other w/l mic users can bug us! mbonis you can find us that little tech paradise can't you!


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## museav (Mar 3, 2011)

chausman said:


> We just need our own little area where we (People using W/l mics) can do what we wnat and no one except other w/l mic users can bug us! mbonis you can find us that little tech paradise can't you!


That is pretty much what is being created with the two UHF 'safe harbor' channels, the only catch is that because the two channels have to work around existing licensed users the specific channels involved, the first open channel above and below Channel 37, will depend on the geographic market.


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## chausman (Mar 5, 2011)

museav said:


> ...will depend on the geographic market.


 
I'm glad I live where not much goes on with wireless!  

And as far as the original question, while Sennheiser's would be great, I would suggest (Like almost everyone else) the AT 3000 series. They work very well and you can get some quality elements to go with them.


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## lparks1 (Mar 5, 2011)

Shure | Axient Wireless Microphone Systems | AXT400 Dual Channel Receiver 

Need I say more? I can't seem to find a price tag -- not that I could afford it if they did. This dual channel monster tunes from 470-698MHz with on receiver and features a computer program that continually scans the entire UHF band and reassigns channels in a millisecond that have interference. I can see this would be helpful on National Tours that run upwards of 20+ channels, but I think it is overkill in any one market.


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## mbenonis (Mar 5, 2011)

lparks1 said:


> Shure | Axient Wireless Microphone Systems | AXT400 Dual Channel Receiver
> 
> Need I say more? I can't seem to find a price tag -- not that I could afford it if they did. This dual channel monster tunes from 470-698MHz with on receiver and features a computer program that continually scans the entire UHF band and reassigns channels in a millisecond that have interference. I can see this would be helpful on National Tours that run upwards of 20+ channels, but I think it is overkill in any one market.


 
I saw this a few months ago. Looks very cool, but I don't see detailed RF specifications on it and so it's hard to say how well it works without taking it to the lab...


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## dboomer (Mar 7, 2011)

mbenonis said:


> 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.



That is correct ... however President Obama has signed a memorandum supporting it's passage. There is a lot of BIG $$$ at stake here and big $$$ always wins.




> 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.



Our PDP(tm) takes care of Wi-Fi as a problem in our XD-V systems although it is a problem to single narrowband devices trying to operate in that band. It is a technology unique to wireless mics.

Don Boomer
Wireless Sales Engineer
Line 6, Inc.


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## Chris15 (Mar 16, 2011)

mbenonis said:


> I saw this a few months ago. Looks very cool, but I don't see detailed RF specifications on it and so it's hard to say how well it works without taking it to the lab...


 
Erm Michael, that's because it, like the PSM1000, haven't actually made it as far as production yet... (As far as I know...)


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## martyclynch (Mar 22, 2011)

Thank you all for your advice so far. I think the AT 3000 series looks far better than anything I looked at before. Reading through this thread has reminded me just how much I do not know about sound. When are one of you guys going to publish a Theatre Sound for Dummies book?


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