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Mic Power Consumption

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Been looking at some short shotgun mics. I noticed that the operating power consumption varies a lot. For instance, the DPA 4017b uses 4.5mA, the 4017c consumes 2.8mA, while the Neumann KMR 81i sips a mere 0.8mA.

 

This leads me to wonder why some mics would be more more power hungry than others. I'm also curious to know whether this difference is significant enough to have a meaningful impact on the battery life of pre-amps, recorders, and... cameras.

 

I'm looking for a mic that will be used in relatively humid conditions and will live on-camera when not being used on a boom.

 

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9 minutes ago, mikewest said:

Why are you worried about power consumption???

 

mike

"battery life", extended time away from AC, and... curiosity?

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the math is quite straight forward: P = U * I

so the DPA draws 0.22W and the Neumann 0.04W on paper

 

compare that with the typical batteries you want to use and you get a rough estimate.

ie a single AA with about 2Wh runs the DPA for 10h and a 40Wh camera  battery for 200h, and five times that on the Neumann.

 

so for most people the power draw is negligible compared to the rest of the gear they run (recorder, wireless etc) and the other factors are far more important on choosing a mic (like how they sound and handle)

bests

chris

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If you look at the field of mics, and choose only shotguns with RF biasing, you get Sennheiser and the Rode NTG-3. I don't have a milliamperage figure for the NTG-3 at the moment but have reached out to someone who should know. (New info from Rode: It requires full spec phantom power and at least 5mA.) Rode very wisely chose to use the RF biasing to decrease humidity problems.

That begs the question of humidity problems. With my CMC641, which I have now owned for over 15 years, I have only had two incidents of humidity problem noise. That's back when I was overly scrupulous. I would dis-assemble the capsule and body after use and store them separately. I cleaned the contacts and stopped doing that and my humidity problems never happened again. My thought is that perhaps exposing the circular gold contacts allows air and schmutz to collect and that creates the noise. If you've never cleaned those contacts, perhaps you should. Be careful! Don't apply liquid cleaner in such a was as to allow it to drip down inside the power supply or capsule. Hold those parts with the contacts aimed DOWN and clean them (gently) from beneath. 

Most of my work has been done in the Mid-Atlantic US. In Summer, it can be EXCEPTIONALLY humid here for days at a time. I don't have data on Amazonian Rain Forests, but sometimes the air is so thick here that you can't see the top of a 1200' broadcast TV tower. 

Finally, one mic will probably create few problems other than shorter battery life, however, I have heard of situations in which multiple amperage-hungry mics could not run on a mixer or console because its amperage rating of the mixer/console Phantom Power supply was not sufficient to feed multiple "hungry" mics. 

 

Regards,

 

Ty Ford

Edited by Ty Ford
more info

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9 hours ago, chrismedr said:

 

so for most people the power draw is negligible compared to the rest of the gear they run (recorder, wireless etc) and the other factors are far more important on choosing a mic (like how they sound and handle)

bests

chris

+1

 

I’ve never actually noticed that different microphones cause different battery life when I’m using them. 

 

-Mike

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The conversion inefficiency of a DC to DC converter (e.g. 12v. to 48v.) is a much greater factor in battery life than is the minimal current draw of a condenser microphone.

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19 hours ago, MartinTheMixer said:

Hello, 

And then there's the Schoeps 2U at a whopping 170ma.

 

7.7 times the power used of the DPA.

 

Thanks, Martin

 

And. perhaps more significantly, the digital version of the above monetized Neumann KMR81i draws 150mA. 

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59 minutes ago, Constantin said:

 

And. perhaps more significantly, the digital version of the above monetized Neumann KMR81i draws 150mA. 

Constantin, "more significantly" because of? I want to make sure I'm not missing something here.

 

Also, that Neumann mic must have some serious downside, no one seems too excited about that one.

 

Sincerely, Martin

 

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1 hour ago, MartinTheMixer said:

Constantin, "more significantly" because of? I want to make sure I'm not missing something here.

 

Also, that Neumann mic must have some serious downside, no one seems too excited about that one.

 

Sincerely, Martin

 

 

No, there‘s nothing you missed. I was merely pointing to the Neumann D, because the comparison between its analog and its digital versions highlight even more the differences in power consumption between the two mics. Also, the OP mentioned the regular 81, so I thought this was information (kind of) pertinent to this thread. 

 

A lot of people use and love both versions of the KMR81i, but as I recently found out, the analog version has got no AM rf shielding, so it doesn’t work with digital transmitters. 

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On 3/7/2018 at 2:30 PM, Constantin said:

...KMR81i, but as I recently found out, the analog version has got no AM rf shielding, so it doesn’t work with digital transmitters. 

 

Good to know, I wasn't aware of that. Thanks.

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