Wireless microphone digital transition

Bernie Hipos

Bernie Hipos

Well-known member
Hi guys, just read an article regarding wireless microphone digital transition. How true and if you are using a sennheiser lav mic, are you affected? I'm using one right now. I don't know if my understanding is correct, according to the article that if you're using a 700mhz freq you're in trouble. I'm always in the 500-600 range though. Anyway, according to them that they're allocating that frequency to public safety. Let me know what you guys think about this. Thanks!

Here's the link to the article.
http://www.vmivideo.com/700mhz.html
 
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We had a very long discussion on this starting back in November:
http://www.dvxuser.com/V6/showthread.php?t=152210&highlight=wireless+future

Truth is, we've known that the 700MHz band was going away for some time now. manufacturers stopped making/selling 700MHz wireless mic systems a couple years ago, and many are now offering 700MHz users the chance to trade in their old systems for credit towards purchasing a new system.

If you have a 500/600MHz system, you're fine. Though, there's still question about what will happen with the White Space. And technically, 700MHz systems still operate... it's just no longer legal to use them.
 
There really should be a sticky on this... :) I'm going to try and write this up in suitable form.

This is very true, and it comes from the digital television transition that happened back in June. Digital TV takes less bandwidth than analog, and so the same number of broadcast channels can all now fit below 698MHz. That left a big chunk of available bandwidth, which the FCC promptly re-allocated.

Only about 4 channels worth of bandwidth (IIRC) have been allocated for public safety; the rest was auctioned off to private corporations. One of these corporations was Qualcomm, which apparently is going to use it for some sort of in-stadium TV channel; a Sennheiser rep told me last week that apparently at least one of these is already up and running at a race track (I think) in Kansas City.

With this re-allocation, the FCC will eventually ban the use of wireless mics above 698MHz (commonly referred to as the "700MHz band" for convenience); the Sennheiser rep estimated that this ban would probably go into effect next June, one year after the DTV transition, but that's not official yet.

So, what does all this mean for people with wireless systems under 698MHz? Well, first of all, a lot of people with system above 698 are going to be buying new systems, so there's going to be more competition for whatever channels are available in your area. The worst of it, though, is still on the horizon, as the FCC struggles to balance wireless mic use with the oncoming "TV-band devices."

TVBD's could theoretically be a lot of things, but the primary purpose that people are pushing right now is for large-scale wireless internet access. TV-band signals are good at travelling long distances, and this makes them very attractive for that kind of thing. TVBD regulation is still evolving, but right now even the preliminary regulations say that TVBD's are supposed to be able to access an FCC database of registered wireless mic users and the frequencies they use, and avoid those frequencies. Which sounds great, except for the nagging little question of who exactly can register as a wireless user. Two people from the company I work for went to a Shure RF seminar a while back, as this was first starting to get serious, and came away with the impression that basically none of our customers (in the business, education, and church markets) were eligible to register under current regulations. That may change, but then again it may not. Last year, an Audio-Technica rep told us that, in his estimation, within about five years there would be no wireless mics operating in the TV band. I don't think that was AT's official position, but certainly they're working very hard on finding alternate frequency bands and I wouldn't be surprised if R&D at Sennheiser, Lectrosonics, Shure, etc. were doing the same. For the moment, alternate-band products like Revolabs or AT's new SpectraPulse system are completely unsuited for broadcast work (partially due to technology, partially due to FCC regulation, and certainly partially due to cost), but if these issues can be solved, they may actually be better than current systems (SpectraPulse, for example, has no compression, so it's transmitting full-range signals).

Hope that helps. :)
 
Captain Pierce said:
Last year, an Audio-Technica rep told us that, in his estimation, within about five years there would be no wireless mics operating in the TV band. I don't think that was AT's official position, but certainly they're working very hard on finding alternate frequency bands and I wouldn't be surprised if R&D at Sennheiser, Lectrosonics, Shure, etc. were doing the same.
Click to expand...

I think what probably will be true, unless they find a hole in the spectrum... is 'analog' FM based RF mics will probably disappear. So, one will have digitization at the mic+bodypack, and then using some digital signalling method to get it to the receiver. In some sense, that may overcome some set of problems relative to interference or multipath... but of course, that will also require better digitization in a smaller package...
 
and probably with any of the higher end makers you can send it your above 700mhz units in and they'll re-crystal them for a different block. I'm sure Letrosonics would do that.
 
I can't speak for Lectro, but Sennheiser USA has already said that they can't or won't do this for G2's. Many manufacturers are offering rebates on 700MHz units, however. Buy a new one, send in your old 700MHz, and they'll give you some cash.
 
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I don't think anybody expects them to do it for free (well, at least anybody living in the real world :) ), but the question, what's more cost effective--rebuild a five-year old unit (I don't think there are many wireless systems in the 700MHz band from reputable manufacturers much newer than that) or just give somebody $100 or $200 or whatever toward a brand new system. And really, given that all 700MHz band mics from reputable manufacturers should be well out of warranty right now, why wouldn't you want to cash them in on a brand-new system if you had the chance to get a couple hundred bucks out of it? (NOTE: I don't know off the top of my head what rebate programs are actually paying, so please don't bust my balls if I get the numbers wrong. :D )
 
Captain Pierce said:
I don't think anybody expects them to do it for free (well, at least anybody living in the real world :) ), but the question, what's more cost effective--rebuild a five-year old unit (I don't think there are many wireless systems in the 700MHz band from reputable manufacturers much newer than that) or just give somebody $100 or $200 or whatever toward a brand new system. And really, given that all 700MHz band mics from reputable manufacturers should be well out of warranty right now, why wouldn't you want to cash them in on a brand-new system if you had the chance to get a couple hundred bucks out of it? (NOTE: I don't know off the top of my head what rebate programs are actually paying, so please don't bust my balls if I get the numbers wrong. :D )
Click to expand...

first off, you think its been 5 years since manufacturers stopped making 700mhz gear? no.
I think i'd cry if i could only get $100 dollars for my lectro 411's block 29's ;) (I just sold 2 off for $2000 each, 2 more to go)

I realize you're most likely talking about a few hundred dollar units but I
think because your other posts have included talking about lectrosonics..that you should mention that.
 
You're right, I was not including Lectrosonics in that post. Are they re-tuning? Honestly, we do way more business with their DM series DSP's than in wireless, our customers just aren't dropping that kind of jack on wireless. :)

As for how long it's been since anybody reputable made 700MHz gear... give me some numbers. Five years was a nice round number, but I'm pretty sure I haven't seen a Shure or AT on that band in pretty close to that. We only signed on with Sennheiser back in '07, but they had discontinued them by then. Again, I can't speak for Lectro, but I'd find it hard to believe that they didn't see it coming either. As for non-reputable... I was working on a bid earlier this year where the customer was absolutely dead-set on a cheap-ass wireless system from somebody called Cetacea, and that was still 700MHz... but it also listed for like $199. How they thought an 8-channel 700MHz system was going to work for 140 classrooms was beyond me, but they would not take any suggestions for an alternate.
 
I dont know the exact dates off hand, but Lectrosonics only stopped producing units in the 700mhz range im guessing..end of last year? (ish)

Yes they will retune but at the cost of about $950 per set
I decided to sell and switch over to their new duel receivers. (lighter on the back)
 
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