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Gear / Technical Help => Microphones & Setup => Topic started by: gunk on December 29, 2017, 03:52:59 PM

Title: What technical difference between lavalier mic capsule and a regular capsule?
Post by: gunk on December 29, 2017, 03:52:59 PM
I want to use a lavalier mic (such as the Rode SmartLav+) to record meetings covertly.  It might be placed hanging out my bag or among my papers.

Are the characteristics of a lavalier mic capsule and different to a regular mic capsule?  For instance, is a lavalier designed to attenuate bass to overcome the proximity effect?

I'm assuming the mic is an omni.

I've seen some articles talk of "transparent" lavaliers and "proximity" lavalier but manufacturers don't seem to use these terms.  What's the technical difference between the two and how can I tell which of those types a particular mic is?

Thanks.



Rode SmartLav+ details can be seen at http://www.rode.com/microphones/smartlav-plus (http://www.rode.com/microphones/smartlav-plus)
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: heathen on December 29, 2017, 03:56:32 PM
Not to be a party pooper, but make sure you're aware of the legalities of this in your jurisdiction. 
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: nulldogmas on December 29, 2017, 04:08:03 PM
Not to be a party pooper, but make sure you're aware of the legalities of this in your jurisdiction.

Here's a handy primer if you need it:

https://www.mwl-law.com/wp-content/uploads/2013/03/LAWS-ON-RECORDING-CONVERSATIONS-CHART.pdf

In short: Don't secretly record conversations you're a part of in California, Florida, Illinois, Maryland, Massachusetts, Michigan, Montana, Nevada, New Hampshire, Pennsylvania, or Washington, or conversations you're not a part of anywhere.
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: DSatz on December 30, 2017, 12:19:39 AM
Fixed-pattern (single-membrane) omnidirectional condenser microphones are pressure transducers, and pressure transducers don't have proximity effect. Still, though, many lavaliers are designed with frequency response that compensates for the odd acoustical situation in which they're most often used--so if you place them elsewhere, they won't sound very natural. But you can equalize the recording if that bothers you.

The terms that you mentioned ("proximity" lavaliers vs. "intensity" lavaliers) aren't in widespread use to my knowledge, and I don't know what they might mean.

--best regards
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: illconditioned on December 30, 2017, 01:08:59 AM
I want to use a lavalier mic (such as the Rode SmartLav+) to record meetings covertly.  It might be placed hanging out my bag or among my papers.

Are the characteristics of a lavalier mic capsule and different to a regular mic capsule?  For instance, is a lavalier designed to attenuate bass to overcome the proximity effect?

I'm assuming the mic is an omni.

I've seen some articles talk of "transparent" lavaliers and "proximity" lavalier but manufacturers don't seem to use these terms.  What's the technical difference between the two and how can I tell which of those types a particular mic is?

Thanks.



Rode SmartLav+ details can be seen at http://www.rode.com/microphones/smartlav-plus (http://www.rode.com/microphones/smartlav-plus)

Interested to know what meetings need to be recorded ... and the legality of doing this.
The simplest "stealth" way to do to this is just to record from your computer or cellphone.
Regular consumer technology makes this easy nowadays ...

Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: gunk on December 30, 2017, 01:18:24 PM
Not to be a party pooper, but make sure you're aware of the legalities of this in your jurisdiction.

Thanks for checking.  All's well and above board as these links show and I don't foresee any problems.  My jurisdiction is the UK.

https://www.gponline.com/medico-legal-patients-record-consultations/article/1227228 (https://www.gponline.com/medico-legal-patients-record-consultations/article/1227228)
http://www.medicalprotection.org/uk/practice-matters-issue-7/digital-dilemmas---patients-recording-consultations (http://www.medicalprotection.org/uk/practice-matters-issue-7/digital-dilemmas---patients-recording-consultations)
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: gunk on December 30, 2017, 01:25:16 PM
Interested to know what meetings need to be recorded ... and the legality of doing this.
The simplest "stealth" way to do to this is just to record from your computer or cellphone.
Regular consumer technology makes this easy nowadays ...

I would like better quality than a Smartphone.  I am starting to think there may be clinical errors in a long-running but failing series of consultations which have led to injury.  My focus is on health and remedying the injury but later, if there has been negligence, then it may give rise to litigation which means I would like the participants at the consultations to be identifiable from their voices.

Recording medical consultations covertly is entirely legal in the UK as you can see from the links I posted in my previous message.

Are you able to provide any info to my original question?

Thank you.
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: illconditioned on December 30, 2017, 05:51:50 PM
Interested to know what meetings need to be recorded ... and the legality of doing this.
The simplest "stealth" way to do to this is just to record from your computer or cellphone.
Regular consumer technology makes this easy nowadays ...

I would like better quality than a Smartphone.  I am starting to think there may be clinical errors in a long-running but failing series of consultations which have led to injury.  My focus is on health and remedying the injury but later, if there has been negligence, then it may give rise to litigation which means I would like the participants at the consultations to be identifiable from their voices.

Recording medical consultations covertly is entirely legal in the UK as you can see from the links I posted in my previous message.

Are you able to provide any info to my original question?

Thank you.
Very good.  Nice to keep records.
The simplest solution I can recommend is a device with built in mics.  My favourite is the Sony PCM M10.  Wrap it in a cloth and put it in a pocket of your bag, with mics facing outwards.
Set it to record, lock the recorder, put some tape over the level controls and you're good to go.

A more complex system will have mics over your ears, but that is hard to wear without others noticing it, or without yourself being distracted by the rig :)


Good luck!

 Richard
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: gunk on December 31, 2017, 01:00:35 PM
Fixed-pattern (single-membrane) omnidirectional condenser microphones are pressure transducers, and pressure transducers don't have proximity effect. Still, though, many lavaliers are designed with frequency response that compensates for the odd acoustical situation in which they're most often used--so if you place them elsewhere, they won't sound very natural.

Hi Satz, Thanks for the info. 

You reply makes me wonder if a really small mic capsule (such as the Knowles FG series, if you know it) might be better because it is not designed as a lavalier but is said to have good performance.

This is the mic I mean https://www2.mouser.com/Knowles/Microphones/FG-BFG-Series/ (https://www2.mouser.com/Knowles/Microphones/FG-BFG-Series/)  The tiny capsule is 2.5mm diameter and it can come with an attached lead which saves the tricky soldering.

Do you or anyone else have any views on this mic?

Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: illconditioned on December 31, 2017, 01:35:51 PM
Fixed-pattern (single-membrane) omnidirectional condenser microphones are pressure transducers, and pressure transducers don't have proximity effect. Still, though, many lavaliers are designed with frequency response that compensates for the odd acoustical situation in which they're most often used--so if you place them elsewhere, they won't sound very natural.

Hi Satz, Thanks for the info. 

You reply makes me wonder if a really small mic capsule (such as the Knowles FG series, if you know it) might be better because it is not designed as a lavalier but is said to have good performance.

This is the mic I mean https://www2.mouser.com/Knowles/Microphones/FG-BFG-Series/ (https://www2.mouser.com/Knowles/Microphones/FG-BFG-Series/)  The tiny capsule is 2.5mm diameter and it can come with an attached lead which saves the tricky soldering.

Do you or anyone else have any views on this mic?
I've used all these mini microphones and more!

The FG series are great, just make sure to get one with leads soldered on already.  Too small for mere humans to solder!!
The noise level of these mics is a bit high, and they clip at high sound levels (rock music), but they are ultimate stealth mics.
I had a pair crazy glued to my glasses.  They were hidden in plain sight!

If size is not an issue my recommendation is the Primo EM172 or similar.  These have the lowest noise of all caps.  And in fact, these are the caps you will find inside  the Sony PCM-M10.

If you want low noise, just get a PCM-M10.

If you want low cost, buy a pair of EM172, you can find them online here, and probably many other places as well,
http://micbooster.com/primo-microphone-capsules/8-primo-em-172-z1.html
http://frogloggers.com/bt-em172/

There is also a smaller version EM-158, and those happen to be pretty good too.  Tascam DR-70D has those, and they are low noise, but not as low as the EM172.

Have fun!

  Richard
 
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: gunk on January 02, 2018, 04:09:24 PM
Hi Richard .......

KNOWLES FG

It's good to meet someone who knows the Knowles FG as they rarely seem to get mentioned.  I use the pre-wired FG capsule (model FG-23329-P07) but I think it may have been discontinued although stocks remain.  The capsule is so small and often doesn't need concealing because it looks like a length of cord on your clothing or bag.

PRIMO CAPSULES AND PIP

Thanks for the heads up about the Primo capsules.  I've been very ill for several years and the last constructor capsule I came across was the Panasonic WM-61A which the Primos seem to supersede as a favorite.  However I only want to record meetings and consultations so I don't need to accommodate high volumes. 

RECORDER QUALITY

What benefit would I get from a higher grade recorder than that Olympus LS-P1, such as the Sony M-10, if I'm only recording meetings and intelligibility along with identifiability are the main priorities?

BATTERY BOX

I think (please advise) I wouldn't benefit much from using a battery box with my Knowles as it runs at 0.9 - 1.6 volts which any consumer grade device (such as my Olympus LS-P1) can easily provide via Plug-In-Power.  The Primos you mentioned need more voltage:  EM172 needs 3 to 10 V, 5V nominal and EM258 needs 5 V but apart from powering the mic to work at all I can't see an advantage in adding a battery box.

Am I on the right track with my thinking above? 

Thanks for any feedback.
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: illconditioned on January 03, 2018, 10:34:42 PM
Do you want to spend your life hacking gear or getting the job done?

Get the PCM-M10 and record with built in mics.  Shockingly low noise, both the built in mics and recorder.  IMO this is the best recorder out there.  Battery life, ergonomics and quality are all outstanding.

Standalone recorder with careful positioning (gaffers tape to secure it in your books or bag with mics pointing out, covered with cloth), and the remote control, you can ensure a successful recording result every time. 

And after that, you if you want to record other stuff, whether ambient sounds, family events, or music, get some external mics and plug in to the M10.

As for Knowles FG, I have run them off the Sony M10 plug in power.  The sound with these little mics is incredible if the volumes are reasonable.  But they are easily overloaded.  I don't think plug-in-power will hurt the mics, but I can't guarantee it.

As for a battery box, I would try to avoid it.  More to carry, and more connections to fail...

Good luck!

 Richard
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: gunk on January 05, 2018, 08:05:47 AM
Get the PCM-M10 and record with built in mics.  Shockingly low noise, both the built in mics and recorder.  IMO this is the best recorder out there.  Battery life, ergonomics and quality are all outstanding.

Unfortunately the Sony M10 is discontinued.  What's the alternative?  Ideally cheaper.

I must have good ergonomics so I can use it without staring closely at menus (like I have to with a Zoom H4).

I am currently using an Olympus LS-P1 which is very similar to the Olympus LS-P2.
Title: Re: What technical difference between lavalier mic capsule and a regular capsule?
Post by: illconditioned on January 05, 2018, 08:42:23 AM
There have been a few M10's forsale here.
Not sure if any are still available.

Buy on the Taperssection if you can :)