Sennheiser G2, soon to be obsolete?!

[davidnssbm]

Captain Pierce, thanks for the reply. Would you mind typing in Seattle, 98105 and the Sennheiser G3 to see the BLUE that I'm talking about? The highlight legend under HELP only has white, green, yellow and pink, yet I get a BLUE option when I type in Seattle, 98105 and Senny G3

 

[Chadfish]

Where does the new G range fall in relation to these freqs? I just sis one for 95521 but I only see 470-704, mostly A or B range.

I just ordered the G3 ENG package with the little butt plug. It's drop shipping from Sennheiser. Woo!

 

[John Willett]

Where does the new G range fall in relation to these freqs? I just sis one for 95521 but I only see 470-704, mostly A or B range.

G3 Range A is 516 - 558 MHz
Range G comes between A and B and is 566 - 608 MHz
Rance B is 626 - 668 MHz.

 

[Captain Pierce]

Captain Pierce, thanks for the reply. Would you mind typing in Seattle, 98105 and the Sennheiser G3 to see the BLUE that I'm talking about? The highlight legend under HELP only has white, green, yellow and pink, yet I get a BLUE option when I type in Seattle, 98105 and Senny G3

OK, I see what's going on there now--it does something different when you select a particular product (I'd never done that before or even heard of it ). The blue highlights there are to show where the three different frequency blocks are, so the first set of blue highlighted frequencies is block A, the second is the new Block G, and the third is block B.

So, looking at that, Seattle is even crazier with RF than I thought. Technically, you don't have any vacant channels in any of the blocks (since you're technically starting on channel 22 with block A, not the vacant channel 21), with 4 low-power channels on block A, one on block G, and 6 on block B. At least at the default 30db attenuation setting, which reminds me...

One thing to consider is whether your use is going to be primarily indoors or outdoors. The "Att" box lets you select that, so if you were only going to be outdoors and wanted to look at the worst-case scenario, you could set that to 10db, and what you're going to see is only channel 40 in yellow. Or, if you're only going to be indoors, you can go to 40db and see a few more yellows open up in block A.

It's kind of an inexact science to diagnose it from this far away, which is why I recommended talking to somebody local and getting a recommendation.

 

[Graham King]

Hey guys & gals. I just picked up the Sennheiser G3 ENG kit with the camera mountable receiver, bodypack transmitter, and plugin transmitter. I'm still getting used to the new menu and I love the sync feature but I am having trouble with the bodypack transmitter.

I scan with the receiver (transmitters turned off) for a clean channel, sync the bodypack transmitter, but no matter what channel I use I'm getting low level interference. When I try the same thing with the plugin transmitter on the same channel, I get a perfectly clean signal. I also tested the channel on my G2 system and it's clean so I'm pretty sure there's either a problem with the transmitter or I'm doing something wrong.

Has anyone else got the G3 bodypack transmitter and have you experienced any problems with it?

 

[jeff9329]

Thanks for the info John! Very helpful.

I'm happy to hear the G3 has adaptive diversity at least. It should give me a more robust signal in the few places I get trouble. Once in a while I get interference from metal jewelry like bracelets. As far as switching frequencies goes, it's usually too late to change settings when I hear the first RF hit. I film seminars or Yoga classes in front of an audience, and can't stop the show.

As I write this I'm starting to think it's just best to save the extra money and get a Lectrosonics unit. But you say that you can't get true diversity in a small receiver? I have use of an older Lectrosonics UCR 195D, that is the size of an 80's era walkman cassette player, and twice as heavy. The unit works wonderfully. It's just the size I have trouble with as a "one man band".

Are you (or is anyone) aware of any smaller, true diversity wireless systems that won't break the bank?

Thank you again.

Chadfish

1. For a more "robust" signal, you need more transmitter output power, not more or selective reciever sensitivity.

2. You would not get active interference from bracelets or jewelry. I would be curious for what you are seeing.

3. Moving to a Lectrosonics with 50 or 100mW output power would be a huge upgrade over the Sennheiser unit, at a cost of course.

Judging from a good bit of reports on forums of people with the same or very similar issues as you, one can't help but wonder if there are not some off-spec or malfunctiong G2 units out there. And thats excluding the pirated G2 knock-offs sold on Ebay. It sounds like some may have very low output power as well as possible other problems.

If you have a tested clear frequency from scanning and looking at the reciever RF level (transmitter off), and then you later have dropouts due to low recieved RF power (not really possible to monitor during a shoot, but during testing) and the transmitter is within (for example) 100 feet of the reciever, I would consider that transmitter defective due to low output. I have a few G2 units and have never had a problem even when the venue has six of their own Sennheiser systems operation on other frequencies.

You should send the unit(s) to Sennheiser for a check or at least go by a radio shop and check the field strength.

 

[Chadfish]

Jeff I have to admit - I have not ever changed the channel on the G2. It's so RF free here in northern Humboldt that it's rare to have 2 people using wireless within the same range. But as far as jewelry goes: I do a math seminar maybe 4 times a year. It usually goes for 3 hours, with the speaker walking all over the room. I rarely get any RF hits. But I have on a couple of occasions got hits that related to her jewelry. She raised her fist to shake it - making a point, and the static reacted to the same rhythm as her fist shaking. I asked her to take off the bracelets and the problem did not return.

I don't thing the unis id defective. I think I just have been lazy. I actually have my own G3 ENG package on it's way directly from Sennheiser! 800.00 from the DVStore. The G2 was my boss' and I wanted my own. I feel dumb after using the G2 for 4 years and not having to change the channel. Or in one case probably having to change the channel (the room never works for me because I get lots of RF hits) and not knowing it. So I'll ask your workflow if it's not too basic.

• Do you scan for free channels first thing when you get to a new location?
• If you find halfway through a shoot you can't stop that you are getting hits, can you change channels from the receiver only without disturbing the talent?
• Can anyone say if Guy''s DV theater quick start video for the G2 will apply to the G3 units?


Thanks.

 

[tallrd]

She raised her fist to shake it - making a point, and the static reacted to the same rhythm as her fist shaking. I asked her to take off the bracelets and the problem did not return.

The following explanation may be of use to many of you.

What you are likely experiencing is common with wireless systems using traditional compander circuits (I believe this is the case is most non-digital systems). Many of the Lectrosonics systems use digital transmission instead of a compander.

The dead-giveaway if you have one over the other is if you rattle a set of car keys (or in your case jewelry) in close enough proximity to the mic for it to pick up the sound. Analog companders can't handle that, and that's what you are likely hearing; not the RF dropping out. It's the compander breaking up. The sound is quite similar though, so it's easy to mistake one for the other.

When shaking a set of car keys in front of a mic plugged into a digital wireless, such as a Lectrosonics, you will hear just that: a set of keys being shaken.

Try it for yourself in a controlled environment, and you'll see what I mean

This is part of the reason Lectrosonics is so well-respected, and also why it costs more.

 

[Chadfish]

I have to hand it to Lectrosonics. I love the quality of the unit I use from work. But that rattling jewelry thing made a definite "static & thud" sound that I sometimes get when nothing is making a noise and my talent is just walking around. Does the sound you describe tallrd sound like that?

 

[tallrd]

yup

 

[John Willett]

1. For a more "robust" signal, you need more transmitter output power, not more or selective reciever sensitivity..

Not sure I agree with this.

If you are only using one radio and no others, a higher power certainly helps.

Receiver selectivity, I would say, is certainly more important than raw power as it concentrates on the wanted signal and rejects others - poor selectivity lets in all sort of cr*p.

For multi-channel use, lower power is better than higher power and you get a much better and safer signal by reducing transmitter power.

 

[j1clark@ucsd.edu]

Not exactly true. Multipath - the fact that the signal from the transmitter bounces around and arrives at the receiver multiple times and all slightly out of phase from each other - can cause a "hit". What can happen is that at one specific antenna, two or more versions of the signal can cancel each other out, causing a null in the response. Different receivers handle such a null differently - sometimes it causes white noise, sometimes it causes a moment of silence, etc. For that moment (or longer, depending on the situation) the background RF engergy on that channel is predominant.

The situation that I was thinking of is were both antennas in an diversity setup, are receiving an approximately equal interfering signal.

In the case of Lectrosonics, is there some form of PN coding on the pilot which would allow the receiver to distinguish an on frequency interferer, and the mic's signal?

 

[Cees Mutsaers]

Can anyone briefly tell me how the the situation is in Europe (The netherlands in my case). I was planning to by lectrosonic stuff for my HPX300 bu the dealer adviced me not to buy this US brand because it works on 700 MHz. He could not give me any other info. So now I am lost what to do if I want a wireless mic. Can anyone give me some advice??

 

[j1clark@ucsd.edu]

Can anyone briefly tell me how the the situation is in Europe (The netherlands in my case). I was planning to by lectrosonic stuff for my HPX300 bu the dealer adviced me not to buy this US brand because it works on 700 MHz. He could not give me any other info. So now I am lost what to do if I want a wireless mic. Can anyone give me some advice??

A brochure for a Bosch wireless mic that I saw suggested that for the Netherlands, a device operating in 852-876 MHz region was recommended. Since it's somewhat difficult finding out this sort of information directly from government documents, I'll take it that in the Netherlands, anything in the 700 MHz band is not authorized...

 

[John Willett]

Can anyone briefly tell me how the the situation is in Europe (The netherlands in my case).

There are lots you can get - G2 and G3 are legal in the Netherlands, for example.

But with digital switch-over happening all over Europe you should seek the advice of the manufacturers main agent in your country to get the best frequencies.

 

[Karlw]

The situation that I was thinking of is were both antennas in an diversity setup, are receiving an approximately equal interfering signal.

In the case of Lectrosonics, is there some form of PN coding on the pilot which would allow the receiver to distinguish an on frequency interferer, and the mic's signal?

Yes, actually. Each of the 256 frequencies within a block has a unique pilot tone "signature" so the receiver can tell if what it is picking up is the intended signal or not. However, the stronger signal always wins - the difference here is that when the unintended (interfering) signal overwhelms the intended signal, you get silence rather than a "hit".

 

[Karlw]

Can anyone briefly tell me how the the situation is in Europe (The netherlands in my case). I was planning to by lectrosonic stuff for my HPX300 bu the dealer adviced me not to buy this US brand because it works on 700 MHz. He could not give me any other info. So now I am lost what to do if I want a wireless mic. Can anyone give me some advice??

Not sure your dealer either knows what's going on or is being honest. Lectrosonics offers our "E01" (export for Europe) versions of our products in a wide variety of frequency blocks, well below 700 MHz to above 700 MHz. Perhaps check with our authorized dealer for the Netherlands: Audio Electronics Mattijsen.

Interestingly, it is the 700 MHz band specifically that is NOT allowed for use in the US any longer....

 

[Karlw]

Not sure I agree with this.

If you are only using one radio and no others, a higher power certainly helps.

Receiver selectivity, I would say, is certainly more important than raw power as it concentrates on the wanted signal and rejects others - poor selectivity lets in all sort of cr*p.

For multi-channel use, lower power is better than higher power and you get a much better and safer signal by reducing transmitter power.

This is a oft-repeated bit that is not totally true. Both transmitter power and receiver selectivity are important, along with the resistance of the receiver to IM (i.e. RF headroom is good).

All things being equal, yes, you might say that lower power is better for multi-channel operations. However, now days, with all the RF junk in the air, this becomes a trade-off. Ideally, you'd want to have fairly high-powered transmitters and highly-selective receivers. One of the down sides of increasing transmitter power, though, is that it becomes easier to generate IMs in the transmitters when they are close to each other. There is a design approach which can overcome that, however. We've done tests with isolated and non-isolated transmitters for close-proximity Intermod generation, and we found that two non-isolated transmitters at 30 mW created more IM products at higher levels than did 250 mW transmitters with isolators.

Bottom line: all things are not equal. Note that even companies who have touted low power for many years as the best compromise now offer variable-power transmitters up to 100 mW.

 

[jeff9329]

Note that even companies who have touted low power for many years as the best compromise now offer variable-power transmitters up to 100 mW.

I didn't realize that any companies touted low power as a good thing. That sounds crazy. To me 100mW is low power. However, I admit even the puny 30mW output of the Sennheiser G2 is adequate in a properly functioning unit. If a company has IM or bleed issues at these low power levels, I would think they really need to work on the design.

I may have break out the 1kW RMS linear amp and experiment some (if it works on 700 mHz).

 

[j1clark@ucsd.edu]

One of the down sides of increasing transmitter power, though, is that it becomes easier to generate IMs in the transmitters when they are close to each other. There is a design approach which can overcome that, however. We've done tests with isolated and non-isolated transmitters for close-proximity Intermod generation, and we found that two non-isolated transmitters at 30 mW created more IM products at higher levels than did 250 mW transmitters with isolators.

Bottom line: all things are not equal. Note that even companies who have touted low power for many years as the best compromise now offer variable-power transmitters up to 100 mW.

This sort of thing was (perhaps still is) rampant in 802.11 applications, where some company claims to have a device that works on 3 'separated' channels at 2.4 GHz... without sharp filters, it is doomed...