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-   -   Unpowered wired lav mic (https://www.dvinfo.net/forum/all-things-audio/512546-unpowered-wired-lav-mic.html)

Nick Mirro December 5th, 2012 09:59 PM

Unpowered wired lav mic
 
Looking for a lav mic with the standard xlr connector attached, no power supply and shirt worn. Can only find unterminated pigtail types that could be converted.

Guess I can learn to solder in a hurry : - ) if necessary. Is there such a product? I would be thankful for any recommendation of something new or used I am working with a small budget of 150.

Battle Vaughan December 5th, 2012 10:42 PM

Re: Unpowered wired lav mic
 
You will probably get better answers but here's a start: Audio-Technica - Microphones, headphones, wireless microphone systems, noise-cancelling headphones & more : ATR3350 Omnidirectional Condenser Lavalier Microphone

This is an inexpensive lav which runs off of a button battery contained in the connecting cord. It would require a mini-plug to XLR adapter. This is a mono plug, Rode makes a stereo-mini to xlr adapter which might work. http://www.campbellcameras.com/shopp...01RODVXLR.aspx

partial discliamer: I have used this little mike on a consumer-level camcorder, it's no Countryman or Tram but it works. Be sure you get the battery right- way-round or it will work really badly. I have not tried mono plug in the stereo plug adapter listed above, I think it will work but I am not positive. At any rate, it's a very inexpensive solution until you find a better one....

PS if you learn to solder you could make an adapter with a mono mini female and an xlr male plug (Neutrik recommended) , common items.at Markertek, Mouser Electronics, etc.

PPS: If you use the xlr, be sure to turn off the phantom power to that input. As pointed out below, the 48v will fry the mike. Ummm, I just found the mini-to-xlr adapter mentioned above, tested it wth the AT lav in my field mixer forgetting about the phantom power, and pffffft.....Otherwise, with no 48v on the line, I THINK it will work....

Steve House December 6th, 2012 04:51 AM

Re: Unpowered wired lav mic
 
Quote:

Originally Posted by Nick Mirro (Post 1766560)
Looking for a lav mic with the standard xlr connector attached, no power supply and shirt worn. Can only find unterminated pigtail types that could be converted.

Guess I can learn to solder in a hurry : - ) if necessary. Is there such a product? I would be thankful for any recommendation of something new or used I am working with a small budget of 150.

You HAVE to have a power supply; condenser mics need a bias voltage to work. Lavs need a bias voltage of about 5 volts. The XLR connector for a hard-wired lav is also a power supply because the normal 48 volt phantom power is too high and will fry the mic if it's not dropped down to the 5 volts the mic requires and the XLR connector/power supply has the component to do that built into it.. A standard XLR connector without the power supply components will not work.

FYI, the XLR power supply module by itself will consume the majority of your budget. You need to budget about $400 or so for most of the mainstream hard-wired lavs like the Tram TR50

Richard Crowley December 6th, 2012 07:38 AM

Re: Unpowered wired lav mic
 
There are dynamic lav mics which require no power, but they are quite rare these days, and may not be easily found within your budget. They are also larger, heavier, and lower-output than more modern electret condenser designs. OTOH, XLR inputs without phantom power are also rather rare and it is curious why you would be seeking such a combination.

Technically, the low voltage required by electret condenser microphones is not "bias" voltage. The electret charge itself is the "bias" or polarizing charge for the capsule. The voltage is required as the operating power for the impedance converter circuit (typically just a single FET transistor). To be sure, it uses very little current, so batteries often last practically the shelf-life of the battery.

Non-electret microphones also require a bias/polarizing charge across the capsule. In modern designs typically provided by the 48V phantom voltage itself. That is why you will find that all low-voltage microphones are of the electret type.

Ref: Microphone - Wikipedia, the free encyclopedia

Nick Mirro December 6th, 2012 12:39 PM

Re: Unpowered wired lav mic
 
Richard, thanks for the Wiki link.

The uninformed goal of an unpowered lav was simply to reduce weight (no battery). I was thinking that the mixer would provide the needed power, but that obviously won't work for many mics as you said.

There is a budget audio-technica on B&H that seems to have very good reviews. Guess the power module can use phantom power instead of its battery.

http://www.bhphotovideo.com/c/product/68272-REG/Audio_Technica_AT803_AT803B_Mini_Clip_On.html

Richard Crowley December 6th, 2012 12:57 PM

Re: Unpowered wired lav mic
 
That AT803 has a power pack practically the size of a deck of cards. If I were looking for something really light and small, I would consider something like...
Naiant

Rick Reineke December 6th, 2012 01:24 PM

Re: Unpowered wired lav mic
 
There are a few dynamic lavs available like the Shure SM11..
Shure SM11
however it has a low output level ( –64 dBV/Pa (0.60 mV), (1 Pa = 94 dB SPL) and would only be good for higher SPL sources.

Jon Fairhurst December 6th, 2012 01:45 PM

Re: Unpowered wired lav mic
 
Quote:

Originally Posted by Richard Crowley (Post 1766682)
That AT803 has a power pack practically the size of a deck of cards. If I were looking for something really light and small, I would consider something like...
Naiant

Wow. The Niant X-X looks like a heck of a solution. The size, price, and sensitivity are all excellent. (And, Richard is right: the AT803b power supply is huge!)

Any experience with how it sounds?

Nick Mirro December 6th, 2012 04:39 PM

Re: Unpowered wired lav mic
 
I followed Steve's point that some sort of power module was inevitable. Oh well, too late now :-) Still feel good about this choice.

Thinking about this, it is probably easier to get the PM and mic situated on me, leave them there for the duration and then plug the xlr into it as needed. Am hiking all over creation and repeatedly setting up. This approach is a bit bulkier but its a small trade off for not having to reattach the mic every 15 minutes.

Considering investing in a llama or one if its smaller cousins. Any recommendations?

Richard Crowley December 6th, 2012 05:21 PM

Re: Unpowered wired lav mic
 
Quote:

Originally Posted by Jon Fairhurst (Post 1766691)
Wow. The Niant X-X looks like a heck of a solution. The size, price, and sensitivity are all excellent. (And, Richard is right: the AT803b power supply is huge!)

Any experience with how it sounds?

I just got two of them. But I haven't had a chance to try them out yet.
You want to borrow them and test them against what you have now?

Christopher Young December 6th, 2012 08:32 PM

Re: Unpowered wired lav mic
 
Quote:

Originally Posted by Nick Mirro (Post 1766560)
Looking for a lav mic with the standard xlr connector attached, no power supply and shirt worn. Can only find unterminated pigtail types that could be converted.

Guess I can learn to solder in a hurry : - ) if necessary. Is there such a product? I would be thankful for any recommendation of something new or used I am working with a small budget of 150.

A while back on a job in the States I got stuck on a weekend urgently needing an extra two lav mics to go into the mixer and grabbed two from Radio Shack. They did a surprisingly good job considering their price. Purchased two XLR plugs and soldered them on in the hotel. Needed to cross wire pins 1 & 3 as they were unbalanced mics. Put pin 2 to the hot lead and all was good. Being electret mics they do need power and are powered by an LR44 type button battery.

Cheap but have hung on to them as back up mics. It been a number of years since I bought them but it looks like the Shack still carries them.

Hands-Free Tie-Clip Omnidirectional Electret : Microphones | RadioShack.com

Chris Young
CYV Productions
Sydney

Jon Fairhurst December 7th, 2012 03:24 PM

Re: Unpowered wired lav mic
 
Quote:

Originally Posted by Richard Crowley (Post 1766743)
I just got two of them. But I haven't had a chance to try them out yet.
You want to borrow them and test them against what you have now?

That would be great. I don't have time for a big test, but I could compare them to a Sanken COS-11D. My wife used to have an AT803b for events, but she donated it to the organization. My e-mail is myfirstname@mylastname.com

Greg Miller December 9th, 2012 03:20 PM

Re: Unpowered wired lav mic
 
Quote:

Originally Posted by Christopher Young (Post 1766774)
... grabbed two [mics] from Radio Shack.
<snip>
Purchased two XLR plugs and soldered them on in the hotel. Needed to cross wire pins 1 & 3 as they were unbalanced mics. Put pin 2 to the hot lead and all was good.

Of course in that scenario, you need to be absolutely certain that the mixer is NOT putting out any phantom voltage on XLR pins 2 and 3! The phantom voltage (sometimes as high as +48vdc) would almost surely fry the unbalanced mic, and the short to ground on pin 3 might do some harm to the phantom supply in the mixer.

Phill Pendleton January 29th, 2013 08:32 PM

Re: Unpowered wired lav mic
 
Just wondering how the Naiant mics went?

David Aronson February 1st, 2013 05:18 PM

Re: Unpowered wired lav mic
 
Quote:

Originally Posted by Jon Fairhurst (Post 1766922)

That's a really cleaver way to prevent spam...

Anyway, It's a little out of your budget, but the Countryman B3 mic is amazing and it's pretty damn tiny.
http://www.bhphotovideo.com/c/product/295908-REG/Countryman_B3P4FF05B_B3_Omnidirectional_Lavalier_Microphone.html


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