Induction Kitchen Nightmare

[VAS]

Today, I have experienced a nightmare in a cooking show.

Wireless & Induction Kitchen

 

Some sort info's: Wireless was Sennheiser G3 (626 MHz - 688 MHz) and G2 (780 MHz - 822 MHz). Lavaliers was DPA 4061. I know, 780 MHz - 822 MHz isn't very good here; but usable. The kitchen was without any extra furniture, so the whole system (below glass surface) was expsosed (not visible to camera of course).

 

When the chef was turned on the kitchen for cooking; wireless went crazy, both of them. The sound was something like huge noise gate, plus extreme denoise, plus extreme compression. Like RF swallow into black hole (use your imagination).

 

I did everything from my side; changing frequencies, changing lavaliers, changing everything with all combinations. Same story: No bueno.

 

Booming was not possible; yes you thinked correctly, extremely wide shoot (master camera) plus exterior (45 meters away was passing a train every 4 minutes). So everyone went crazy because of "sound problem", the kitchen nightmare; not the train nightmare. I have asked a simple question, if we had that kitchen from previous season. Guess, the answer was "no". And the story goes crazy.

 

Next time, cooking show, I will ask what type of kitchen will be. After "where", "when" (and why in my inner thoughts).

[Mungo]

That induction inducts the mic itself and the cable between lav and transmitter, I guess, so changing frequencys won't help unfortunately. 

I even had that once with a wired(!) MK41 (!).

Recently talked to a Sennheiser developer about this issue. It was new to him that this is a big problem for us. For oncoming products they will think about testing induction noise (within the other tests a new product runs through before thrown onto the market). 

[Ilari Sivil]

I wonder if the Neutrik EMC-connectors could be of any help? Seems pretty problematic in any case, especially since induction stoves are pretty nice to use so people may be reluctant to give them up. Another thing to check up on for future gigs, I guess...

[VAS]

Hi Ilari,

 

I tried a starquad cable from receiver to recorder; still no bueno.

The problem was from transmission side (tx and lavalier).

I wonder if I had a digital wireless, things was better; but I don't know.

[pkautzsch]

 

On 4.3.2018 at 12:31 PM, Ilari Sivil said:

I wonder if the Neutrik EMC-connectors could be of any help?

With wired boom mics, maybe.

 

On 4.3.2018 at 1:53 PM, VAS said:

The problem was from transmission side (tx and lavalier).

I wonder if I had a digital wireless, things was better; but I don't know.

When talent is close to a source of interference, the main culprit usually is the unbalanced connection between mic head and transmitter.

Therefore, digital wireless would only transmit the compromised audio signal more faithfully.

I doubt the induction field was strong enough to hit your receivers, you must have been a few meters away if it was an ultra-wide shot.

Did you do a scan?

[Mike G]

The same happened to me too a couple of weeks ago, when using Sennheiser G3s and MKE-2s in a cooking show. I had several different induction ovens in the set/shoot.

So the interference on the G3s was from non to extrem noise gate. I had a room tone boom too, so in post we fixed the gated sound in the mix.

 

Anyway, I found this plausible explanation by Larry:

 

 

So if you guys have a chance, use other transmitters than G2 - G3, when shooting with induction.

Any experience with other brands, besides Sennheiser?

[jpb2]

what do you think about wrapping the stove in foil and grounding it in a pinch?

[LarryF]

Try wrapping your hand tightly around the lavaliere mic and see if it at least works like a lavaliere wrapped up in a hand. This will block possible supersonics (24 kHz). You should get really muffled sound. You can also tap the cable and see if you get the usual cable noise. This doesn't solve the problem but at least it would show that supersonic noise through the air is the problem.

Best Regards,

Larry Fisher

[mikewest]

Thanks for that observation Larry.

There is a similar problem with large HMI lamps on-set that produce a high level noise at 19kHz

My ears cannot hear that!!!

Regards

 

mike

[Malcolm Davies Amps CAS]

6 hours ago, mikewest said:

Thanks for that observation Larry.

There is a similar problem with large HMI lamps on-set that produce a high level noise at 19kHz

My ears cannot hear that!!!

Regards

 

mike

That's interesting Mike, the HMI high level noise on the larger lamps used in the Uk is always14kHz

[IronFilm]

On 3/13/2018 at 10:19 PM, Malcolm Davies Amps CAS said:

That's interesting Mike, the HMI high level noise on the larger lamps used in the Uk is always14kHz

 

Strange because both countries are 50khz

[LarryF]

1 hour ago, IronFilm said:

 

Strange because both countries are 50khz

50 Hz not 50 kHz (50,000 Hz). 

Best Regards,

Larry Fisher

[BRYAN DAY]

The same happened to me too a couple of weeks ago, when using Sennheiser G3s and MKE-2s in a cooking show. I had several different induction ovens in the set/shoot.
So the interference on the G3s was from non to extrem noise gate. I had a room tone boom too, so in post we fixed the gated sound in the mix.
 
Anyway, I found this plausible explanation by Larry:
 
 
So if you guys have a chance, use other transmitters than G2 - G3, when shooting with induction.
Any experience with other brands, besides Sennheiser?

Lectrosonics SSM cos 11 and / DPA mini no problem same situation


Sent from my iPhone using Tapatalk

[LarryF]

3 hours ago, BRYAN DAY said:

Lectrosonics SSM cos 11 and / DPA mini no problem same situation


Sent from my iPhone using Tapatalk

The reason (probably) the Lectro was not affected is that the Lectro does not have multiple sections of pre-emphasis (treble boost) as does Sennheiser. It is exactly the reason some transmitters have problems with the key test; the large boost of supersonic frequencies. Also, the Lectros do a fair amount of supersonic roll off very early in the mic gain stage. This makes me strongly believe the induction cook top was a supersonic audio problem and not an RF problem. Thanks for the update.

Best Regards,

Larry Fisher

[VAS]

Thank you guys! I learned a lot!

 

[berniebeaudry]

Arc welding can have an effect on wireless as well.  I've never had an issue with Lectro gear around it.

[Mike G]

On 29.3.2018 at 5:47 PM, BRYAN DAY said:

Lectrosonics SSM cos 11 and / DPA mini no problem same situation


Sent from my iPhone using Tapatalk

 

Thanks Bryan for the update on the topic!

 

On 29.3.2018 at 9:50 PM, LarryF said:

The reason (probably) the Lectro was not affected is that the Lectro does not have multiple sections of pre-emphasis (treble boost) as does Sennheiser. It is exactly the reason some transmitters have problems with the key test; the large boost of supersonic frequencies. Also, the Lectros do a fair amount of supersonic roll off very early in the mic gain stage. This makes me strongly believe the induction cook top was a supersonic audio problem and not an RF problem. Thanks for the update.

Best Regards,

Larry Fisher

 

Larry, I think you're 100% right. Thanks for sorting that out. 

[Dalton Patterson]

Very informative read. 

[Jule]

I experienced something similar, but with the 5000 series / Sennheiser - and it was not with induction ovens but with the ultrasonic connection of hairpieces (extensions) at the hairdressers. The radio link could not be used at all.

[daniel]

On 3/30/2018 at 3:13 PM, berniebeaudry said:

Arc welding can have an effect on wireless as well.  I've never had an issue with Lectro gear around it.

I've had problems when recording surgical operations when they use a Electrocauter for cauterisation. I think it's creating a mini arc which results in a 'splat' on the channels of some radio mic (and a smell of burning flesh). 

[Pat Slater]

On 09/04/2018 at 5:19 AM, daniel said:

I've had problems when recording surgical operations when they use a Electrocauter for cauterisation. I think it's creating a mini arc which results in a 'splat' on the channels of some radio mic (and a smell of burning flesh). 

I have done a lot of recording in surgery over the last few years, my set up with cos-11 into lectro has never had problems from any high frequency medical equipment, including the cauterising systems. The smell does put me off meat for a while ( usually only lunch.... )

[daniel]

1 hour ago, Pat Slater said:

I have done a lot of recording in surgery over the last few years, my set up with cos-11 into lectro has never had problems from any high frequency medical equipment, including the cauterising systems. The smell does put me off meat for a while ( usually only lunch.... )

Good to know. IIRC, my mid range sennheiser RMs were sensitive to the cauterising, the cheap Sony UWPs (i had as back up) worked fine.