UHF Woes

[mbenonis]

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 ), but at the same time I don't want to skimp in one area to better another...

My take: go for the Lectro's and get B3's. But I'm biased.

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

Yeah, their setup works just fine, but if it were me doing it I would place a 7th distro unit at the top, and use it to split a pair of antennas three ways. I dislike the idea of having all of those antennas in the air...

I don't believe there is any technical reason why this can't be done.

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!

Yep. Check your PM in a few minutes here for some info.

Mike

 

[jamesmiller]

Yeah, their setup works just fine, but if it were me doing it I would place a 7th distro unit at the top, and use it to split a pair of antennas three ways. I dislike the idea of having all of those antennas in the air...

I don't believe there is any technical reason why this can't be done.

From my understanding, each antenna needs a "booster". The booster is frequency group dependent, and must be matched with the proper range of the receivers / transmitters. So the booster essentially makes each antenna have to operate in "A", "B" or "G" groups.

Unless I understand this wrong?

Quotes from the Sennheiser article:
2. Determine whether you will need an antenna splitter(s) based upon the number of channels you
require. A rule of thumb is that you will need a splitter for every four channels. Also, one great .
advantage splitters offer is that they will provide DC power to the receivers. A single splitter will
power up to four receivers. Additionally, you will need an AB2 antenna booster for each antenna.

Determine where you wish to place your antennas. If you wish to keep them at your rack, you will need
an AM2 kit for every splitter you have, unless you optimize the cascading feature of the splitter, which
allows the operation of eight receivers of the same frequency range from one pair of antennas.

4. If you are configuring a large system (as with the sample 16-channel system on pages 20-21) you
will be able to configure the splitters in a way that reduces the total number of antennas needed to
one pair for every eight receivers. This is done by jumpering the splitters (see your owner’s manual).

I may be able to reduce the number of antenna's to 3, but that will add an additional 3 splitters to the setup.


PS) Got your PM. Thanks.

 

[mbenonis]

From my understanding, each antenna needs a "booster". The booster is frequency group dependent, and must be matched with the proper range of the receivers / transmitters. So the booster essentially makes each antenna have to operate in "A", "B" or "G" groups.

Unless I understand this wrong?

Quotes from the Sennheiser article:
2. Determine whether you will need an antenna splitter(s) based upon the number of channels you
require. A rule of thumb is that you will need a splitter for every four channels. Also, one great .
advantage splitters offer is that they will provide DC power to the receivers. A single splitter will
power up to four receivers. Additionally, you will need an AB2 antenna booster for each antenna.

Determine where you wish to place your antennas. If you wish to keep them at your rack, you will need
an AM2 kit for every splitter you have, unless you optimize the cascading feature of the splitter, which
allows the operation of eight receivers of the same frequency range from one pair of antennas.

4. If you are configuring a large system (as with the sample 16-channel system on pages 20-21) you
will be able to configure the splitters in a way that reduces the total number of antennas needed to
one pair for every eight receivers. This is done by jumpering the splitters (see your owner’s manual).

I may be able to reduce the number of antenna's to 3, but that will add an additional 3 splitters to the setup.


PS) Got your PM. Thanks.

I see now. According to the article, the ASP2 is a passive splitter - basically, a glorified cable TV splitter designed to higher specifications. It doesn't amplify the signal at all (like the Shure units do, among others). This has advantages and disadvantages. The main advantage is that the splitter itself cannot cause any sort of intermodulation interference within itself. The disadvantage is that you lose 7 dB of gain from input to output (approximately), and if you do the loop-through thing they suggest, the total loss from input to loop to output on the second side is 14 dB! So yeah, in that case, you definitely need an antenna booster. Also - you will need at least two antennas per band split that you have - you can't get away with less.

Actually, thinking about it...you could actually do it the way I described above, with a seventh splitter and a pair of antennas for the whole system. Basically, you'd take a pair of antennas, feed it into an ASP2, and take three outputs from each side and feed them through an AB2, and then into another ASP2, and do the loop-through thing. Though this would not be the optimum gain structure as you're attenuating from a splitter and from cable before amplifying, which is a not a good thing. But if your cable runs are short from the antennas to the ASP2, you can make it work.

If you were to go with six antennas, though, which you certainly can do (there' no technical reason why not to do it this way, other than looks), then you want to make sure the AB2's are located AT the antennas and not at the ASP2. Just FYI.

And for antennas, I still suggest an antenna like the ALP500 (in fact, you can use that exact antenna with any brand of wireless system - antennas are not brand-specific in any way unless they have an onboard amplifier (which has specific power requirements). I'm sure Sennheiser makes one as well but I'd have to dig to find the model number.

Follow, or did I lose you there in my mumbo jumbo?

PS - This discussion has been great for me; I had not thought of some of the ideas Sennheiser presented before.

 

[Chris15]

Perhaps the best option lies in a hybrid of bits and pieces already discussed...

Would it not work to run an active splitter at the head end with a pair of wideband paddles or helicals and then feed that to the passive splits (which would be useful for their rationalisation of plugpacks and no doubt cost benefits.

The Sennie ASA3000 is wideband and has 8 outputs so with that at the head you could foreseeably feed 32 receivers via 8 intermediate ASP2s. It's specced for untiy gain, so you might still need AB2s on the inputs of the passive splits to make up the 7dB of splitter loss. At that point you have a net 3dB gain (+10 - 7). If you used an AB3700 instead of an AB2, you get a wideband gain of 5 - 15dB (not sure how that works) and with that on the head end you should theoretically (assuming that you don't overload the active split) be able a distribution system gain not far off unity.

Note however that there are other, probably cheaper, ways to get 7dB. Helical antennas are specced to 8dB of gain and the Sennie passive batwings (LDPAs) will have a couple of dB of gain and a few dB down when everything else is right should not present issues.

I have to wonder if the cost of 6 separate antennas plus coaxes might add up, it will factor more if long cable runs are needed...

Clear as mud?

 

[jamesmiller]

Could it not work setup like this?:

It seems to me to be the easiest setup for the system. Don't know if it would actually work or not, but it LOOKS like it would according to the information provided in the G2 Brochure (even though these are not G2's).

Thanks,
James

PS) Chris, the document says the ASA3000 is only for use with the 3000 series receivers? Don't know if they will work with the G3's.

 

[mbenonis]

Yes, that would work, though be aware that the cascaded ASA-1 outputs will be about 7 dB weaker in signal strength than the first ASA-1 outputs (this is post the "antenna booster). Also, with this setup, be sure to have the antennas very close to the head ASA-1 and the antenna boosters to avoid any more attenuation than necessary (which will add noise).

 

[jamesmiller]

Okay,
I had a meeting with the financial team today, and we have come to a decision. We are going with Lectrosonics. The company wants to highest quality we can afford, since we are charging each performance at $15,000 + 20% Box office , they don't want to skimp in the wireless dept. and have the audio not work when we get there.

About to place the order for 21 x VRT, 21 x LMa, 2 x ALP 500, 4 x VRMWDB housings as well as some good quality Coax.

Mic elements are still TBD. We were going with B3's, but the company wants something smaller. So we are looking into the B6, E6 or clones there-of market. Most of the other microphones are out of our budget (I really don't want to spend more than $200 on a mic element since are forking out close to $30k for wireless).

Just thought I'd offer an update.
Thanks!

 

[jkowtko]

Smaller than a B3? Broadway uses DPA 4061s almost exclusively, and they're pretty much exactly the same size as the B3. If your company wants the best equipment, then you should be buying the DPA 4061s ... they're 2-3x the price, but that's what the pros use. You just need to hide them well within the hairline, build a few earloops for those bald actors, and get your costumer/makeup person to camoflauge them carefully. But that's a different thread ...

Fyi, I'd be cautious on the E6i. In addition to them being cardioid, which many claim will not produce as natural a voice response as omni, I've seen them flop around a lot on the face, and I've heard complaints about the behind-the-ear connector being very succeptable to moisture and resulting popping/crackling. I've rarely seen them used outside of school (i.e. novice) theaters. When boom mic was required, DPA4066 was used and the visibility issue was dismissed in favor of better sound.

 

[mbenonis]

Congrats! I will say this, though - don't skimp on the installation. Your installer should come out and do the whole install, including walk testing and an inspection of the RF environment using an RF spectrum analyzer (better installers will do a site visit with RF test gear before spec'ing out the frequency blocks). In addition, they should provide you with coordinated frequencies for your local area (and, of course, spec out the correct frequency blocks for your use). In essence, the system should work out-of-box when they walk away and be trouble free for years (with support when you need it).

 

[derekleffew]

...don't skimp on the installation. Your installer should come out and do the whole install,... In addition, they should provide you with coordinated frequencies for your local area ... the system should work out-of-box when they walk away and be trouble free for years (with support when you need it).

Umm, Mike, did you forget that jamesmiller intends to tour this gear all across the US? Doesn't that change the "installation" somewhat?http://www.controlbooth.com/forums/members/jamesmiller.html

 

[jamesmiller]

Other than "installing" it in the rack, I don't think much will happen in the way of "installing" it. As fare as blocks go, I am going to place the order based on an even spread (or as even as possible), with 3-4 receivers in each block. Since we are going all across America, I'm hoping this will provide is the best chance of getting usable frequencies.

Also going to place an order for a very nice Shock-Rack to mount the wireless in, the OSP SC16U-20SL. I have also decided that it's best to keep the wireless at the road mix position, therefore instead of being on stage, it will be with the FOH mixer.

DPA are out of the price range for us (at least $400 per element!). If anything, it looks at either the Countryman B3, OSP HS 09, or something in that $100 - $200 per element price range.

PS) Also buying a nice rack-mount PC to put in the case as well, for computer control of the software.

 

[mbenonis]

Umm, Mike, did you forget that jamesmiller intends to tour this gear all across the US? Doesn't that change the "installation" somewhat?http://www.controlbooth.com/forums/members/jamesmiller.html

D'oh! I was thinking of another thread, I think (that, or by brain is fried...one of the two). Nonetheless, I still stand by my statement that you should buy from a vendor that can provide support when you need it -- i.e., if a bodypack fails they can overnight you one so you're back up. That level of support is invaluable.

 

[Chris15]

D'oh! I was thinking of another thread, I think (that, or by brain is fried...one of the two).

I say brain fried, can't even type my... That or a combination of both. That said, there are a number which I find blur together, so you're not alone...

In relation to a previous point, The Sennie ASA3000 should work with non 3000 series receivers. We've said before that Antennas and distribution are manufacturer independent unless powering of remote antennas is involved. There are exceptions and you couldn't put it past the Germans, but Sennie do normally play by the rules.

Alas, that doesn't matter now.

Don't forget some sturdy stands to get those antennas up above the punters heads and avoid some issues there.

 

[jamesmiller]

Don't forget some sturdy stands to get those antennas up above the punters heads and avoid some issues there.

I talked with the people at OSP today. They are going to custom design a case for our needs. Basically, it will have two retractable antenna poles in the rear of the case that can be raised and lowered into the rack for transport. According to them, they should lift at most 10 feet out of the rack.

Anyone ever used these OSP cases before? Seems pretty cheap but very well made...

Thanks!

 

[jamesmiller]

Still have no placed the order for the wireless yet. I'm trying to lobby for the SMQa transmitters

I like the 250 output, compared to 50 from the LMa. They are also smaller...

 

[Chris15]

I like the 250 output, compared to 50 from the LMa. They are also smaller...

That's about 7dB of difference...

There are other ways to get 7dB of gain but it depends on how your bean counters want to play it...

There are fewer ways to shrink transmitters.

 

[mbenonis]

Still have no placed the order for the wireless yet. I'm trying to lobby for the SMQa transmitters

I like the 250 output, compared to 50 from the LMa. They are also smaller...

I'd go for the SMDa rather than the SMQa. Not only will battery life be much, much better, but you don't need 250mW. Period. 100mW is pushing it for stage use (due to intermod problems and the like), 50 mW is the pro norm, and 10-20mW is common from many lower-end manufacturers. Trust me on this, with LPDA antennas within 100-200' of your stage, and VRT receivers (you are getting VRT modules, aren't you...and if you aren't, put money here first! Receiver quality is MUCH more important than transmitter quality), 100 mW will be more than enough transmit power for your needs. Trust me on this.

PS- if you go for the SM line, get the remote. You'll like it.

Mike

EDIT: Reading back, I see that you are getting the VRT modules. Good. One more thing - have you factored in the cost of the IAS software package? If you're getting this much wireless and touring with it, you'll need the software.

 

[jamesmiller]

Already purchased the IAS software. Only went with the basic version, since we don't need to Coordinate more than 30 frequencies just yet.

Point taken on the SMQa. Looks like I may not get my approval for the SM line though.... Each receiver is twice the cost of the LMa. Looks like the order is going for the LMa's.

We also have decided on Countryman B6 elements