Jump to content

Lavalier mic not working


Patrick Cooper
 Share

Recommended Posts

Some time ago, I ordered a lavalier mic via eBay. My very first lav mic. Though I cannot get it to work. I have connected it to three devices (two phones and a Samsung tablet) and used different audio recording apps and I'm not having any success. It seems that when I record audio, the device's internal mic is being used and the lav mic is ignored (despite being plugged in.)

With the testing I have done, I kept the device fairly close to my face and also had the lav mic fairly close to start off with. During the recording, I would move the lav mic further and further away as I was talking but kept the device close by. Then I would bring back the lav mic in close again. Upon playback, the apparent loudness of my voice stayed the same. It was obvious that the device's internal mic was being used. I also did another test where I would keep the lav mic close to my face while I talked and moved the device further away. This resulted in my speaking voice getting softer in volume and sounding more distant. Another clear indicator that the lav mic is being ignored by the device.

I do admit that I'm completely new to using lav mics. Would there be something obvious that I'm missing? I'm just assuming that when a lav mic is plugged into a device, it's detected and utilised by an audio recording app by default. Though I'm not really sure if that is the case. The lav mic I have is YouMic which seems to have some positive reviews online.

I also have a general query about recording good quality audio. I confess that my knowledge of audio is not great. The app I'm using at the moment is Voice Record (available to iPhones.) It has a VU meter and there is an adjustable Input Gain. I find that I have to raise the Gain extremely high while I'm talking so that the needle gets close to the edge of the red zone in the VU meter. And the phone is quite close to my face. Upon playback, my voice has good volume but there is a huge amount of background noise (despite being in a mostly quiet room.) It sort of sounds like static and is very distracting. Any tips on getting rid of that background noise or at least reducing it? Obviously, if I lowered the Gain, that would help but my speaking voice would also sound much softer. 

Link to comment
Share on other sites


The phone should switch to the lav mic as soon as it is plugged in. The fact that the devices do not recognize the microphone is enough to explain it does not work. Usually smart-phone or tablet jacks are 4-pins TRRS (Tip Ring Ring Sleeve): Tip (left channel) and first ring (right channel) for stereo audio out, second ring for mono audio in, and sleeve is common ground. Maybe you are not using the proper cable. If your lav uses a 3-pin TRS minijack, you probably need a 3 to 4 pins adapter.

Smart-phones use "intelligent" detection: if nothing is plugged, no need for audio out nor audio in. If a TRS jack is plugged, 2nd ring and sleeve are shorten so no need for audio in (the phone guesses it is a simple pair of headphones). If 2nd ring and sleeve are not shorten (impedance different from zero), there must be an external mic plugged in so audio in is activated and replaces internal microphones.

Other than that, smartphones or iPads are not meant to be pro-grade audio recorders. Especially with the internal microphones that face the challenge of getting decent intelligibility without being properly placed, and discard the ambient noise. Using lavs or external mini-shotgun microphones should strongly help though, and may meet your needs.

Edited by Nicolas POISSON
Link to comment
Share on other sites

Someone with more knowledge will chip in, hopefully, but generally you need directionality to get rid of off- mike sound. Lavs can be directional or not- check which you have. Everyone remembers rifle mics with the fluffy covers which were very directional.

Normal speech shouldn't get near the red zone- it's to stop really loud sounds from distorting. I'm no expert but I think I would aim for -5 or -3 tops.

Also, are you sure that the app actually does override the Iphone's automatic gain control?

Edited by Mark Dunn
Link to comment
Share on other sites

45 minutes ago, Nicolas POISSON said:

The phone should switch to the lav mic as soon as it is plugged in. The fact that the devices do not recognize the microphone is enough to explain it does not work. Usually smart-phone or tablet jacks are 4-pins TRRS (Tip Ring Ring Sleeve):

Yea there is the possibility that the mic is defective. This particular mic is TRRS. And I'm using the cable that was supplied with the mic.The last device I used it with was an iPhone with a 3.5mm input. 

Link to comment
Share on other sites

28 minutes ago, Mark Dunn said:

Someone with more knowledge will chip in, hopefully, but generally you need directionality to get rid of off- mike sound. Lavs can be directional or not- check which you have. Everyone remembers rifle mics with the fluffy covers which were very directional.

Normal speech shouldn't get near the red zone- it's to stop really loud sounds from distorting. I'm no expert but I think I would aim for -5 or -3 tops.

Also, are you sure that the app actually does override the Iphone's automatic gain control?

I was under the impression that most lav mics were omnidirectional though I know there can be some exceptions. Yea I'm sure I could get even better audio quality with a shotgun mic connected to my camera. Though as I'll be recording myself speaking for youtube videos, it's going to be awkward manually adjusting the audio levels on a camera that is facing me. So a lav mic connected to a phone or tablet will have to do.

Ah I was under the impression that all audio sources need to be close to the red zone with the occasional clipping being acceptable. I didn't know that speech could be a bit softer.

I do hear a difference when I adjust the gain. Also, the higher the gain is, the closer the needle gets to the red zone. When the gain is pushed all the way to the maximum, the needle is right on the edge of the red zone and the static-like background noise is pretty loud and distracting. 

On youtube, Ive heard audio samples of dialogue from various lav mics (and most of them were omnidirectional) and none of them had that background static noise. 

Link to comment
Share on other sites

Auto gain (ALC) is much better than it used to be so you could try it when you get your mic sorted out. With your VU meter, I'm pretty sure you can drop the level down quite a bit- it's easy to do a test, if the app will control the phone mic.

Link to comment
Share on other sites

34 minutes ago, Patrick Cooper said:

Though as I'll be recording myself speaking for youtube videos, it's going to be awkward manually adjusting the audio levels on a camera that is facing me.

You can set up the audio level before any real recording, looking at the VU-meters at the back screen of the camera. Then you activate the limiters (if any) and just use the camera facing you, forgetting about sound and trusting your previous set-up. It may require a few trial-and-error, as you might speak louder during real takes (3 to 6dB more is common). Big plus: no need to sync audio afterwards. Even a $100 shotgun mic above your head on a stand will give much better sound than a lavalier.

I guess this is the way most solo you-tubers with decent sound do. Nobody is able to think to its speech while constantly checking audio levels simultaneously.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...