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UHF Woes

Discussion in 'Sound, Music, and Intercom' started by jamesmiller, May 18, 2009.

  1. jamesmiller

    jamesmiller Member

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    After spending much of today doing some frequency evaluations with Sennheisers online tool, and I hit a road-block in several of our tour cities.

    I ordered 18 of the new G3 100's, with 6 receivers in each of the 3 frequency groups (22-27, 33-37 and 40-45) available for use in United States. I was hoping that this would give us maximum flexibility in getting enough frequencies available... WRONG.

    According to Sennheisers software, several of our cities have NO available channels in the bands we need to use. For example, they are looking to do a show in Brooklyn, NY... Here is the readout according to their software:
    --------------------------------------------------------------------------
    Channels Radius Att Available
    --------- --------- ------- ---------------------------
    33-37 70 mi 30db (mixed) None
    22-27 70 mi 30db (mixed) None
    40-45 70 mi 30db (mixed) None

    It didn't fare any better with a 40db (indoor) Att, with only an additional 3 channels that are "possibly" available in the 22-27 band.

    It's at this point that I'm starting to wish I had made the purchase of a Sabine wireless systems in place of UHF.

    Know, this is New York after all... So to be fair, I did an evaluation at another venue we are playing at. The software did show some available channels at various other cities, but most where "Should be usable" and not "Vacant".

    I don't recall having this much trouble with our Sabine system, which we only have 9 channels of.... So that one can't work for our show. And since the Sabine system is going on the "Wonderland" tour, its not available to use.

    I'm stuck here... Any suggestions? If I can't get this figured out, I'm going to return the Sennheisers and spend a few extra thousand on a new Sabine setup for our tour...

    Thanks,
    James

    PS) Please don't say we should have gone with Shure's UHF-R. At nearly $3,500 per channel, that won't happen.
     
    Last edited: May 18, 2009
  2. BillESC

    BillESC Well-Known Member Premium Member

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    For New York, you could call Masque Sound and rent. They will know (and have) what frequencies will work.

    I did a quick check with the Audio Technica ATW 3000 series and there were 37 channels available.
     
  3. jamesmiller

    jamesmiller Member

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    Thanks Bill.
    I really like the Sennheiser systems, I just hope that we won't run into too many problems, as far as finding 18 usable frequencies at most cities. I liked the fact that they have 3 available band splits, and there price is very attractive ($600 per channel, includes receivers, transmitter and mic).

    I don't know if I'm "overreacted" by relying on their software to tell me for sure what is going to work, or even if I should up the att to 40db or even 50db when doing these evaluations.

    I did look into the AT 3000, and it does show several available channels with that system, although they do operate in different band-splits than the Sennheiser.

    Has any one got any comments on these new G3's from Sennheiser? Did I make the right decision in buying them? When I use a 40db (indoor) instead of 30db (mixed), it shows more available frequencies... What should I really use in this case? All of our shows take place inside a Theater...

    I suppose renting in each city (where our systems wont operate) could work, but it will add to the presenters price to perform the show.

    Thanks,
    James
     
    Last edited: May 18, 2009
  4. mbenonis

    mbenonis Wireless Guy Administrator

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    OK, calm down. :) First of all, fancy...I hadn't heard about the new G3 until now. Looks cool, though I can't find a detailed spec sheet anywhere (got one handy? I'd like to look at it).

    Now, first of all, when does your tour start? Is it before or after June 12? If it's after June 12, you may be in luck as many analog channels will be going off the air, and the digital ones will be moving around. It looks like Sennheiser's site is showing EVERYTHING, including stations that are not currently on the air (but will be), and stations that will be going off the air (but are on now). So, you're going to have to do a bit more sleuthing to find out what's really there, and what the website is telling you is there.

    Second, you need to know where these shows will be. Will they be in a big building that will knock down the RF from outside, or will be they be outside on a mountaintop? If it's inside, you might be able to get away with some mics on TV channels that are in use, but fairly far away. Of course, the only way to know whether it will work is to try it on site.

    I could encourage you to do some planning ahead of time, but don't try to run your frequencies now - wait until you get on-site and do some scanning around with your receivers (antennas in final positions, etc). Also, I recommend looking at the IAS software package from Professional Wireless (see the FAQ for a link). It's a bit smarter than web tools are in terms of finding free frequencies, and it's what the pros use when they coordinate stuff for you. It's costly, but it'll save you money in the long run. There's also a 15 day demo I believe.

    With reference to the Sabine stuff...I don't like it. In short, it uses the unlicensed 2.4 GHz band, which means you are at the mercy of anything around you. Every Wi-Fi enabled cell-phone, bluetooth device, computer, and new gadget has the potential to take your mic off the air at the most important moment in the show. Also, at 2.4 GHz, propagation is poorer due to reflections, attenuation from walls and structure, and reception is poor due to cable attenuation (meaning your receivers need to be really close to the stage). While I haven't worked with them extensively, others have told me that their audio quality isn't nearly as good as Sennheiser, Shure, or Lectrosonics.

    With UHF, at least you can know in advance what will be there (mostly).

    Feel free to ask any additional questions and I'll do my best to help!
     
  5. jamesmiller

    jamesmiller Member

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    Features of the Sennheiser 100 Series Evolution G3 Wireless:
    Sturdy metal housing (transmitter and receiver). High-quality true diversity reception. Pilot tone squelch for eliminating RF interference when transmitter is turned off. Auto-Lock function avoids accidental changing of settings. HDX compander for crystal-clear sound. Handheld transmitters feature easy-exchangeable microphone modules from evolution series.

    NEW: Automatic frequency scan feature searches for available frequencies.
    NEW: Wireless synchronization of transmitters via infrared interface.
    NEW: Enhanced frequency bank system with up to 12 compatible frequencies per bank.
    NEW: 42 MHz bandwidth: 1680 tunable UHF frequencies for interference-free reception.
    NEW: Increased range for audio sensitivity.
    NEW: Illuminated Easy-to-Read dot matrix graphic display (transmitter and receiver).
    NEW: 4-level charge indicator for transmitter battery.
    NEW: User-friendly menu operation with more control options.
    NEW: Enhanced AF frequency range.
    NEW: Soundcheck mode.
    NEW: Integrated equalizer.
    NEW: Contacts for recharging the BA 2015 accupack directly in the transmitter.
    NEW: Integrated guitar tuner (for use with belt pack transmitters).

    Operates in the following bands
    A - 516MHz - 558MHz
    B - 626MHz - 668MHz
    G - 566-608 MHz

    Official Website
    http://www.sennheiserusa.com/newsite/category.asp?transid=catG3Sets


    PS) All of our shows will take place in a traditional theater building... Nothing outside.

    The tour will be starting this fall... September to be exact.
     
    Last edited: May 18, 2009
  6. mbenonis

    mbenonis Wireless Guy Administrator

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    Do you have the technical specifications? I'm interested in their claims for RF performance...

    Also, I forgot to ask, what kind of antennas and antenna distribution system did you purchase? This will have a large effect on how your system will perform in tough RF environments.
     
  7. jamesmiller

    jamesmiller Member

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    I was not able to find much in the way of "tech sheets" for the system. It appears that Sennheiser itself does not even acknowledge existence of any accessories for the system, even though DirectPro carries them.

    Now, on to the setup. Below is the graphic I made a few days ago on how the system would work.

    [​IMG]

    From the way everything looks, it seems like it's a workable system, but then again, I'm not an audio technician. :lol:

    Thanks,
    James.
     
    Last edited: May 19, 2009
  8. mbenonis

    mbenonis Wireless Guy Administrator

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    James, check your PM inbox.
     
  9. jamesmiller

    jamesmiller Member

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    Mike,
    I got your PM. I was unable to contact you today because I was out of the office most of the day.

    I downloaded the ISA software, and it looks great. Except for the fact that it does not have the G3 system programed into the software. Even doing a scan with the G2 bands, it still shows more channels available than the online tool did.

    Does anyone know how to use the "Generic" method and manually enter the frequency ranges? I tried choosing generic, and entered the range of the 1st band to check and then entered 0.025 for frequency steps (which was already there), and it seemed to work... However, according to the page about the the 100 G3's, it says:

    "the 100 series offers twenty channel banks with up to twelve presets each, with one further channel bank freely programmable in 25 kHz steps."

    What exactly that means, I don''t know. So I don't know if setting the entire frequency range at 0.025 steps is right or not.

    Anyone?
    Thanks!
     
    Last edited: May 19, 2009
  10. mbenonis

    mbenonis Wireless Guy Administrator

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    You're doing it right. Forget about channel banks; all you need to do is generate a list of frequencies and plug them straight into the transmitters and receivers (one per, of course). That should be very easy to do with the Evo units.

    You should also be able to create new device profiles, I believe (I haven't used the software in a bit and don't have it in front of me). These would have the start, stop, and step values that go with the system (step is 25 kHz, or 0.025 MHz). But it sounds like you're already off to a good start.

    I will be free between 12:30 ET and 2:30 ET tomorrow (Wednesday) if you want to try me then; if that doesn't work we can set another time. I would like to talk with you about your overall setup though. :)
     
  11. jamesmiller

    jamesmiller Member

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    Mike,
    I'm doing a setup today at a local theater, so I won't have time to chat...

    I just wanted to pop online and say that our order for the above units did not process. Apparently, our payment method did not go through.

    I'll have to talk with the Gods that be tomorrow about WHY this happened.

    Anyway, I'm actually kind of happy about it. I'm going to do some more investigated into other systems or better setups for this system before I make another purchase order. I'm looking into maybe even the 300's instead of 100's. The seem to have more features than the 100's and are only a few hundred more a channel.

    I wish we could afford Lectrosonic's! :(
    From the looks of it, they can't afford these either hahahahaha.

    PS) Since the NTSC band is going away, should I remove that from the results on the Wireless System Analysis software? IT seems to free up more channels with only ATSC selected.

    Also, how much spacing is required? Are all of the frequencies shown by the software usable by the system, or do I need to keep a require spacing between them?
     
    Last edited: May 20, 2009
  12. mbenonis

    mbenonis Wireless Guy Administrator

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    No problem. If you want to e-mail/PM me and set up a time, that'd be fine. Given that the order didn't go through, I definitely want to make sure you get the right antennas and antenna distro (I don't think the ones you picked will work terribly well).

    Agreed. I think you'll find the PC control particularly useful in your case - the included software will let you scan the venue, and will present you with a view of what is going on and let you pick frequencies that will work for you. I actually called Sennheiser about it yesterday, and they tell me it works quite well (and answered some technical questions I had about how it worked). I think the RF side of the 300/500 receivers (which look to me to be identical save for different software) is better than the 100 series.

    The SM transmitters are pricey ($1400 or so) but they are solid as a rock. They do make less expensive ones though...but I think the Sennheiser set is a very good choice for you.

    Correct. Disregard any station that is listed as NTSC, UNLESS it is a translator or a Class-A Station. In those cases, you need to dig deeper to see if/when that station goes off the air. But full power TV should be dead by the time the tour starts (OK, save for extended nightlight stations but I think those die within a few months as well).

    You should space channels no closer than 500 kHz. I like to give over 1 MHz, and with 6 channels per 42 MHz block this should not prove to be a problem for you.
     
  13. jamesmiller

    jamesmiller Member

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    After doing some figures today, the Lectrosonic's may actually be doable. I can get a 6 channel rack, 6 x receivers and 6 x LMa transmitters for around $1,100 a channel.

    That's not including the distro and antennas, but at that rate, its on par with the Sabine units, which they had expressed interest in.

    After doing investigations into the Lectrosonic frequencies, they offer plenty of choice as to run more than we need, which could be good for future upgrades.

    Any suggestions on the Lectrosonic's?

    Thanks
     
  14. mbenonis

    mbenonis Wireless Guy Administrator

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    I am a very big fan of Lectrosonics' gear. I consider it to be some of the best in the industry, and the Venue is a VERY good receiver system. I have 17 channels worth where I work and it is absolutely rock solid wireless. I have not once had a problem with it.

    The Venue receivers have an antenna loop-through, so you will not need any antenna distribution. Also, with the wideband frames you can select any block receiver module for each slot. I recommend two ALP500 antennas to go with the system and good coax (LMR400 for runs over 10 feet). That'll add a few hundred to the total system cost.

    It is worth noting that you will need to factor the cost of elements into the Lectro system (some of the Senneheiser systems come with elements in the box). For B3's, that's $150 extra per channel plus a few spares.

    I'll be honest here. If the cost of elements puts you close to the edge in terms of cost, I'd backpeddle to the Sennheiser 300 series and make sure you have extra elements and the like on hand.
     
  15. jamesmiller

    jamesmiller Member

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    Here's the issue. They really want to mic all the actors, which I think they said was 24 total. The reason I was figuring in 18 on the G series was because that seems to be pushing available frequencies in most places.

    With the Lectrosonic's, we can easily run 3 receivers in each of the bands have plenty of space (theoretically) to mic all 24 actors. According the Intermodulation software,there is around 15 available frequencies, even in cities like NY, within each block.

    Personally, I think I'm gonna really look into the lectrosonics, just to save us headaches while on tour, and for future expandability.

    Also, I like the fact you don't have to do antenna splits, run multiple distro's, etc. I also like the way there 6 in 1 design will save rack space... Very nifty.

    Also, I already factored in the purchase of plenty of Countryman B6 Lavs (other than $250)

    Thanks

    Edit: Is there a major difference between the VRT and VRS receivers?

    Second Edit: If I knew that I could work with the G3's to get enough available channels, I would be willing to buy them and save more money... I just don't want to buy something that won't work everywhere. It would heck to show-up for a show and only be able to find 1/2 the required channels...
     
    Last edited: May 21, 2009
  16. mbenonis

    mbenonis Wireless Guy Administrator

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    It is interesting that you are getting more frequencies for the Lectro units per block than you are for the G3 systems, especially given that (a) a block size for the G3 is 42 MHz wide while the Lectro's have 25 MHz blocks, and the G3 let you tune at 25 kHz steps while the Lectro's are 100 kHz steps. Perhaps you can send me some reports for a sample city for each system that you have made?

    Personally, I think that you should be able to get at least 8 channels per bandsplit with the G3 units, and probably more. This would certainly allow you to do 24 systems. If it were me, though, I would buy 9-10 systems per bandsplit. Not only does this save you if a transmitter or receiver dies, but it allows you to weight one split over another in some cities with bad RF environments. Remember that with the Sennheiser, though, you'll need to factor in the cost of two antennas (LPDA type, not sure what the model number is) and enough antenna distro systems to make it work (for 30 systems, you'd need ten antenna distro's and two passive two-way splitters, plus perhaps a broadband preamplifier but I'm not sold on this if you use passive, high gain antennas and short coax runs - plus, preamps can be overloaded by TV stations). The Lectro would not need a preamp, but if you were to run four Venue receivers I would probably do a passive two-way split and then loop them in two pairs.

    I will note that the Lectro units have a much better RF front end than the G3's do (or, at least than the G2's do). Along these lines, the difference between the VRS and VRT modules is the front end. The VRT modules have a tracking front end filter that helps to kill off-channel interference. I want to say that this filter is 11 MHz wide, which is much, much narrower (better) than the VRS (25 MHz) or the Sennheiser (42 MHz). Given the small incremental cost of VRT, I would go with it, especially given that you are going to work in NYC.

    If I may ask, what vendor are you going with, and is it negotiable at this point? For a system this large I might recommend going with a pro vendor, like PWS or Bexel ASG (neè Systems Wireless) who sell wireless exclusively.
     
    Last edited: May 21, 2009
  17. jamesmiller

    jamesmiller Member

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    Mike,
    I can't do a report that large, as the software wont allow anything over 30 frequencies. It's not that were getting more frequencies per block with lectro, its that we have more blocks to choose from. Therefore, instead of placing 6 or 8 channels in 1 block (G3), we only need to place 2 or 3 in each block (Lectro).

    And really, both seem to show similar available frequencies in some cities. For instance:

    Block 19 of Lectro was showing 16 available, while block A of the G3 was showing only 14. This was Brooklyn, NY though. Of course, that's not "usable" frequencies because I did not account for spacing yet.

    I did some playing around with the software, and to be honest, your right. The only 3 cities where we would have trouble getting 24 though is New York, St. Louis and Chicago. Beyond that (according to the software), the G3 has enough channels for 24 (with 1MHz spacing).

    Our original order was placed with Performance Audio by the way. The B3's we have on order from Northern Sound.

    Actually, let me run a report and post it here. I'll do a report for Brooklyn, NY. After more investigating, It appears the even Brooklyn can handle 8 units in each band split with the G3, although just barely. It's not leaving much room for error, but here are the two reports (I already added the 1MHz spread):
    http://www.scribd.com/full/15680303?access_key=key-b773ru1jvdr0l7lz8w8 (G3)
    http://www.scribd.com/full/15680302?access_key=key-21a5dhsjmmnutb2xn1vi (Lectro)

    The reason I did this for Brooklyn is because if we can operate there, then we should not have any trouble anywhere else... I believe NY would probably be the most UHF heavy city.

    I also did a price-list based on 3 systems. These are of course retail prices, with no discounts figured in yet:
    24 Channel G3 100 setup: $18,977.00
    24 Channel G3 300 setup: $25,000.00
    24 Channel Lectro setup: $29,000.00

    If it comes down to between the 300 and Lectro, I'll probably do Lectro. That's only a $4k difference. On the other hand, if we can stay with the G3 100 and make it work, then we are wonderful :).
     
    Last edited: May 21, 2009
  18. jamesmiller

    jamesmiller Member

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    Also,
    Did they ever clear up the white-space issue yet? Are they still going to auction off unused white space? If so, has the FCC agreed to put any road-blocks in place to help protect wireless mic operation?

    Mike, I seen your article on your website where you contacted the FCC about this issue. Any updates?

    Thanks
     
  19. mbenonis

    mbenonis Wireless Guy Administrator

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    Got it. Be very careful of Block 19, though, as some cities have two-way radio systems that operate here for Fire/EMS/Police and you don't want to interfere. I'm not sure if IAS knows about this or not.

    Agreed. Yeah, it looks good. Even if you can't get a 1 MHz spread, 800 kHz or so would be fine if thats what it comes down to.

    For what it's worth, I think your Lectro estimate is about right, assuming that it factors in the cost of the mic elements. If it doesn't, than it's high by about $4000 give or take. This is for VRT, by the way.

    Regarding white spaces. The FCC has decided to allow unlicensed devices to operate in the TV bands. They sold off the 700 MHz spectrum, but the rest will be unlicensed devices that can operate on an ad hoc basis - meaning you have no way to predict what will be in the air. Realistically, they will likely serve to increase the noise floor, and potentially decrease range but with proper antennas and good coordination, as well as strong RF signal paths, you'll be just fine with either system. In theory, the Lectro's with VRT modules will probably be better against white space devices but I think either system would be fine.

    In theory, these devices are supposed to detect wireless mics, but who knows if it'll actually work.
     
  20. jamesmiller

    jamesmiller Member

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    They have a finalized list of venues which our tour will be playing. Apparently, they have suspended all "booking" by presenters this season, and instead have booked or are planning on booking (?) the following Theaters:

    IU Auditorium - Bloomington, IN
    Clowes Hall - Indianapolis, IN
    Morris PAC - South Bend, IN
    TPAC - Nashville, TN
    Palace - Louisville, KY
    Aronoff Center (P&G Hall) - Cincinnati, OH
    Paramount - Aurora, IL
    Civic Center - Peoria, IL
    Palace - Marion, OH
    Allen Theater (Playhouse Square) - Cleveland, OH

    They are also saying that they want to push back the dates for the tour from September to February... Something to do with availability of a few of the venues I think...

    Again, I don't know if they have booked these yet, but they seemed pretty firm in their decision at the meeting today. They even had complete budgets for each of the venues.

    This means that my job does become a but easier. All of the venues provide large stages, so we don't have to worry about adapting to smaller or larger stages at each venue (this season anyway).

    Also, I have done a complete evaluation in these cities for the G3 and Lectro, and both seem to show a fair amount of available frequencies. I had a little bit of trouble in Aurora, IL (A suburb of Chicago) with the G3, but nothing that can't be worked out with either system.

    Now the question is: Which one to buy. Really, its between the G3 100's and Lectros at this point. The 100's would save us some dough (which I would like to be able to buy those B6 instead of B3's :lol: ), but at the same time I don't want to skimp in one area to better another...

    Above available frequencies, there are many thing I like about the Lectro's. The fact that they all fit into a 6 in 1 chassis is nice, and they don't need distro's and a number of antennas to work right. This means could fit our entire wireless setup in a nice little package.

    The G3's are nice as well, but eat up major rack-space with 24 individual receivers and 6 distro's (and that's just a 24 channel setup). Also, I seem to be having a hard time figuring out the best way to setup that many G3's.

    It appears that (according to the Sennheiser document "Working with the Evolution Wireless G2"), that you cannot "daisy chain" the distro's to each other. Therefore, each distro will need a separate antenna, which brings the total antenna count to 6 (instead of 2 with Lectrosonic's). This is of course for the G2 series, but I figured most principles apply to the G3 as well.

    Unless or course, I am misunderstanding the document. In the document, they show a sample setup of a 16 channel system. I was just kind of "building" on that system in a similar fashion as described to bring it to 24 channels.

    Mike, perhaps you can make some sense out of this setup. Attached is a link to it, and its on page 20 I believe. This was the same system diagram I used in placing the original order for 18 of the G3 100's.

    http://www.sennheiserusa.com/workingwithewg2/working_with_ewG2.pdf

    If we go with Lectro, I'll just skip block 19 then.

    Understood. With only 800 kHz, we should no no trouble finding enough channels with the G3.

    This pricing was actually for 4 x VRMWBL, 24 x VRS receivers and 24 x LMa transmitters through Performance Audio. With the VRT, it came close to $33k without the microphones included.

    This was of course going off of retail price, and I would hope with this large of an order, that they would have a discount of some sort in place for us.

    Thanks!
     
    Last edited: May 21, 2009

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