Sanken CS1 and Cell interference

[chris_bollard]

Hi All

I seem to to be getting hits when I use my Sanken CS1 from crew and cast cell phones. (GSM). I ask for everyone to turn their phones off but silent mode seems about the best that can be mustered.

Does anyone have any suggestions? Is there an inline filter that I can use - or is it to do with the pyscial size of the CS1 and the wavelength of the GSM transmissions? No problems with the 416...

[ProSound]

You can try the Neutrik EMC connectors that are suppose to help RF issues:

http://www.neutrik.com/us/en/audio/210_1822126843/NC3FXX-EMC_detail.aspx

This may help if not switch to a 416 if your having an issue.

[Jeff Wexler]

I seem to to be getting hits when I use my Sanken CS1 from crew and cast cell phones. (GSM). I ask for everyone to turn their phones off but silent mode seems about the best that can be mustered.

The CS1 in my experience has not been any more or less immune to GSM cell phone interference. The GSM interference, now often referred to as an iPhone problem, used to be less prevalent since prior to the iPhone there were less GSM devices on the set. As you pointed out, the only real solution is to turn the phones OFF --- silent mode doesn't cut it of course.

The 416 will not be subject to these problems since the design of that mic is totally different than most all of the other "modern" microphones. This is why many people keep a 416 ion their kit to solve these problems.

Regards,  Jeff Wexler

[Reid]

Would some one explain why GSM causes interference.  Reading info such as

http://mobiledevdesign.com/tutorials/radio_introduction_gsm_gsm/

leads me to think the narrow fq control and low power would minimize rf.  Why is the opposite true?

Thanks

[studiomprd]

your simple question is actually way too complex for an easy answer and is also way above the typical technical level of www.jwsound.net. 

RF is a really complex subject involving lots of math, physics, and voodoo!!

ultimately, it doesn't matter why or how cell phones (particularly GSM) or other devices create problems,  but the fact is, they do create the problems.  sometimes interference comes from improper operation of devices, but the fact is that it often comes from proper operation of the equipment and technology, and wireless microphones are secondary users, who by definition (FCC!) must not cause interference to primary (licensed) users, and also must accept and deal with any interference resulting from proper operation of and by a primary licensee.

As for our other (non-wireless mic) equipment, and even other electronics in general, if licensed, or approved equipment is operating correctly as specified, any interference it creates is, under the current situation,  something that has to be accepted and dealt with.  In the grand scheme of things, our problems are trivial compared to what others are dealing with!!

[Reid]

Snarky...not an answer .....but.......to the point.      Coffee anyone???

[Alan]

Hi All

I seem to to be getting hits when I use my Sanken CS1 from crew and cast cell phones. (GSM). I ask for everyone to turn their phones off but silent mode seems about the best that can be mustered.

Does anyone have any suggestions? Is there an inline filter that I can use - or is it to do with the pyscial size of the CS1 and the wavelength of the GSM transmissions? No problems with the 416...

I ditch my CS1 and Neumann KM185 for these reasons, even with inline filters and stuff. The Schoeps, Neumann AK45, MKH416 & 50 handle it pretty well in my case. Even the CS3e gets it occasionally. I do have inline filters on my boompoles but when it comes, it comes ( tick tick tick tick tick ).

Alan

[Daniel McIntosh]

I recently sold my Schoeps CMC4 and upgraded to a CMC6.  I was told it was immune to iPhone chatter. Unfortunately it does not seem to be any more immune than my CMC5, whether hardwired or wireless.

[Jeff Wexler]

I recently sold my Schoeps CMC4 and upgraded to a CMC6.  I was told it was immune to iPhone chatter. Unfortunately it does not seem to be any more immune than my CMC5, whether hardwired or wireless.

I don't think anyone thought the new design Schoeps would be RF immune to GSM problems but it definitely is an improvement (and a total fix in some cases like video transmitters) but it has not in my experience completely eliminated GSM (phone) problems. Also, you say you have upgraded to CMC6 but you don't say that it is a NEW CMC6. The CMC5 and CMC6 has both been around for quite awhile and both were subject to significant RF problems for years. It is only when the CMC6 was upgraded, by Schoeps, were the problems solved. I believe a mod can be done by Schoeps to any CMC6 to make it about as RF immune as it can be. Make sure your particular CMC6 is a new one (new design with RF suppression).

-  Jeff Wexler

[ProSound]

My newest issue recently is producers are clipping there comtek next to the Iphone or in a pocket with it despite me explaining this is why they are getting chatter it doesn't work they still complain. Is the Lectro IFB more Iphone or GSM immune?

[Jeff Wexler]

My newest issue recently is producers are clipping there comtek next to the Iphone or in a pocket with it despite me explaining this is why they are getting chatter it doesn't work they still complain. Is the Lectro IFB more Iphone or GSM immune?

The GSM noise that's getting into the Comtek headset is most probably NOT a function of the RF receiver part of the Comtek pack. They could have headphones plugged into an iPod and be listening to music and have GSM noise/chatter in their headphones if the GSM phone is close to iPod (or Zune player which I mention just so as to be balanced). My point is, the GSM noise is very insidious and gets into everything --- I have had GSM noise come through the speakers of my MacBook since the phone is on my belt and the laptop is on, my lap for example. I don't think you would have less problem with a Lectrosonic IFB receiver since the sound may actually be getting into the headphone amp just as it is with the Comtek or any other device.

-  Jeff Wexler

[Daniel McIntosh]

Make sure your particular CMC6 is a new one (new design with RF suppression).

I bought the CMC6 less than one month ago.  I will email Redding with the serial# and see if this can be determined.

[Noah Timan]

I believe a mod can be done by Schoeps to any CMC6 to make it about as RF immune as it can be.

I had this done by Schoeps in Germany for $250 and the mic came back just as RFI-prone as it ever was, so a word of caution there.  Maybe I just had bad luck as I have heard other people say their Modulous/Canatrans problems went away. 

[John Blankenship]

I bought the CMC6 less than one month ago.  I will email Redding with the serial# and see if this can be determined.

You can easily tell if it is the newer version yourself.  Look into the connector end of the microphone.  If there is a ground plane (copper metal) around all the pins, then it's the newer version.

JB

[rafaeldelauz]

I ditch my CS1 and Neumann KM185 for these reasons, even with inline filters and stuff. The Schoeps, Neumann AK45, MKH416 & 50 handle it pretty well in my case. Even the CS3e gets it occasionally. I do have inline filters on my boompoles but when it comes, it comes ( tick tick tick tick tick ).

Alan

I have a new version of the Km185 and Km184 and I found both extremely well shield against RF, specially the 185. I used to have the old version and it was a nightmare, but with my new guys I have pratically the same reliability that with my MKh416.

[RPSharman]

On the very first day of any production, I ask the 1st AD to announce that if people are ON SET while we are rolling that their phones must be off and not just on silent.  I explain that it interferes with the microphones.  I also ask that it be mentioned again on days with lots of extras, which serves to remind the crew also.  If a take is runied by cell phone interference, then I explain that it is indeed on the track, and I explain the cause.  Cell phones are soon turned off.

As for Comteks.  This happens all the time.  I explain that it can be helped by not keeping their phone in the pocket near the Comtek, but typically with producers sending and receiving texts and emails CONSTANTLY throughout the day, the problem is persistent.  It is a greater problem when the director or camera crew are wearing Comteks on set.  The headphones may not be loud enough to feed back, but the da-da-da-dadada-da-da-da can often be heard bleeding through.  This once again reinforces NO CELL PHONES ON SET.

It's always a delicate conversation, and I try to have it as little as possible.

Robert

[Noah Timan]

On the very first day of any production, I ask the 1st AD to announce that if people are ON SET while we are rolling that their phones must be off and not just on silent. 

Yeah, that always works....<g>

[johnpaul215]

I've also had issues with a hardwired Sanken CUB-01. I am not sure if it was the CUB-01 itself or the XLR cable i plugged it into. This was a car setup, and i was curled up in the back. The actor in the passenger seat had an iPhone in her bag on the floor (on top of my cables).

I guess the nice thing about Comteks being vulnerable is that they all get to hear how bad that noise really is..... and can't blame anyone but themselves.

[Noah Timan]

A good place to start troubleshooting, though it may seem obvious, is attacking what's immediately in front of the microphone -- the actors.  Often the actors will have a personal cell phone in a pocket or purse and that's the culprit, and in those instances frantically running around trying to shut down every crew or video village smartphone won't help. 

I do remember one show a couple of years ago where John Leguziamo always had a noisy GSM Treo in his pocket and every time we got a GSM hit we'd ask him if he'd turned his phone off, and he'd reply with a sheepish look.  He was very good about letting me confiscate it until we got the shot.

[johnpaul215]

I just wanted to chime in here and give some relief to the iPhone.  Blackberry phones also utilize the GSM signal, and as such can give the same problems as the iPhone.  This is not an iPhone issue.

To be fair, it does not apply to Blackberries and Treos on Verizon or Sprint. They use CDMA. The iPhone is the new blame because 1) they now outsell Blackberries and 2) they all have GSM radios in them. Blackberries have a roughly 50/50 chance of being GSM.

[RPSharman]

To be additionally fair, I have heard this noise for years, long before iPhones.  Regardless of phone type, Comteks are affected in close proximity.  Regardless of phone type, CUB01 are susceptible to noise (I have noticed this more in cars).

While the GSM phones have created greater problems for more devices at greater distances, all communication devices on set can give us problems.

[old school]

Hey RVD, commercials are the worst when it comes to people talking on their cell phones. Producers, cameramen, even directors talking during a take. I point out the obvious a time or two, but then.... what can ya do. One producer I work for has a policy that whoever has their phone goes off during a shot, bang he or she pays 10 $$$ to his favorite charity. Even with this heads up, he takes in 50.00 or more a day for the "Heal the Bay".

CrewC

[RPSharman]

I had a 1st AD on set with a similar rule, but it was $20 into the dollar day bucket at the end of the week.  No more than a few hours after announcing his policy did his cell phone ring on set.  He answered it with, "Thanks, Honey.  You just cost me 20 bucks.  What can I do for you?"  A funny moment.

I must still point out, Richard, that I have had interference with standard cell phones (not Nextel or GSM) , most notably with the CUB in a car.  It has also occurred with actors directly under a mic, both with 50s and CMCs.  It also happened with a regular phone hanging on the side of my cart, charging.  It rang while on charge, and the close proximity to my DV824 sent it right into my headphones.  This was over 2 years ago, so I can't remember if it was on the track or just the headphone amp.  Regular phones have far less of an impact than iPhones, etc., but they still pose a problem.

Robert

[Philip Perkins]

Is there any truth to the story that James Cameron would confiscate any cel phone that went off on his set and would nail the phone

to the wall near the door?

The Neutrik EMC connectors help some, but just some (Sanken, Schoeps, Neumann). 

Maybe we could make a deal with the big techo-communication companies:  they develop a new cel-phone technology that doesn't interfere with our equipment and we'll shut up about all those "white-space" devices.

Philip Perkins

[johnpaul215]

I had a 1st AD on set with a similar rule, but it was $20 into the dollar day bucket at the end of the week.  No more than a few hours after announcing his policy did his cell phone ring on set.  He answered it with, "Thanks, Honey.  You just cost me 20 bucks.  What can I do for you?"  A funny moment.

I must still point out, Richard, that I have had interference with standard cell phones (not Nextel or GSM) , most notably with the CUB in a car.  It has also occurred with actors directly under a mic, both with 50s and CMCs.  It also happened with a regular phone hanging on the side of my cart, charging.  It rang while on charge, and the close proximity to my DV824 sent it right into my headphones.  This was over 2 years ago, so I can't remember if it was on the track or just the headphone amp.  Regular phones have far less of an impact than iPhones, etc., but they still pose a problem.

Robert

I have run into it with any GSM (AT&T, T-Mobile) phone, and that includes "regular" cell phones.... like the freebie Nokia phones that a lot of people (used to) have. Treos on AT&T/T-Mobile are terrible, but i use a Verizon one and can wrap my cables around it. I've never had a problem with a Verizon or Sprint phone.

I wish AT&T phones didn't do this, but they do. It's THE reason i don't have an iPhone.