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External Mic on Galaxy Devices

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AdamOutler

Retired Senior Recognized Developer
Feb 18, 2011
5,224
9,812
Miami, Fl̨̞̲̟̦̀̈̃͛҃҅͟orida
Hey guys, I worked on adding external microphone features to my device for a dog-gone long time yesterday... about 5 hours. Elite Recognized Developer Rebellos searched the code and we figured out that the device wouldn't recognize my mic because it's ohms are too low. The WolfsonMicro chip uses any value below 1000 ohms to signify button presses. Above 1000 ohms it signifies a microphone. My microphone is a 900 ohm microphone, so in all actuality, it's pretty high considering most are around 100-500 ohms. However, Rebellos and I managed to hack through it. I wanted to share this method.

My target device is a Galaxy Camera, but Samsung has used WolfsonMicro chips in their devices for a long time. This also works on the Galaxy Note 2 so Its logical to assume it will work on others.

Here's the finished solution. A Samsung 4-pole to 1/4" Mic adapter with a 200ohm resistor inline.
20121229_121732.JPG



Introduction
attachment.php


The Galaxy Camera and Note2 require over 1000 ohms of resistance in order to recognize that a microphone is connected to it. So, there's two ways to do this.

1. Buy a microphone with over 1000 ohms of impedance.
2. Add some impedance.

Now, adding impedance will reduce the volume of the microphone, but that's not an entirely huge issue as adjusting volume is not a big deal. However, adding a resistor will slightly distort the waveform but even with this slight distortion it's not going to destroy the sound quality because it's a very slight ripple which in most cases will not affect the compressed recording quality.

Getting things together
Everything you need to add external, directional audio is available at Radio Shack for less than $35 USD. Buy a better microphone with higher ohms for louder sound. You get what you pay for.
1. 1/4" Mono In-Line Audio Jack (2-pack) - RS Part Number 274-0340 - $5
2. a set of Samsung Earbuds with 4-pole connections
3. optional - microphone Unidirectional Dynamic Microphone - RS Part Number 3303038 - $19.99 - note the old one is 900ohms. The new one is 600 ohms.
4. optional - Biasing Resistor - you will need to do the following equation to determine the ohmage of resistor you require. $5
1100 ohms - (ohms of your microphone stated in the manual) = ohms of resistor required to turn on the microphone.
1100 ohms - 900 ohms = 200 ohms of resistance required
5. Epoxy and Superglue $5

Building the adapter
Building the adapter is quite simple Samsung uses 7 wires in their headphones. Bare wire is not connected to anything. 3 are copper colored in clear shields there is a Blue or Green, Red and White as well. The 3 copper are the common leads The White is the microphone.

  1. Cut the connector off the headphone, leaving 3 inches of the cable.
  2. Cut all of the wires except for one Copper and the White wire.
  3. Strip and tin the Copper and White wires.
  4. Solder the copper wire to one side of the 1/4" Mono In-Line Audio Jack
  5. *Optionally* If required to exceed 1100ohms solder the resistor to the white wire
  6. Attatch the white wire (with resistor if used) to the center post of the 1/4" Mono In-Line Audio Jack.
    At this point you can verify your setup works.
    20121229_104711.JPG

  7. superglue the wire to hold it in place for the next step
    20121229_105045.JPG
  8. Mix up your epoxy and apply to the resistor, wire and jack connections in a way to support the following:
    1. to keep the wires from touching anything
    2. to prevent physical strain on the electrical connections
    You'll want to ensure that the epoxy is a light coat which totally surrounds the wire, resistor and large metal pads on the 1/4" audio jack. But don't let it go down inside the jack because it can prevent the microphone from connecting properly.
    20121229_105648.JPG
  9. slide the 1/4" jack cover down over the epoxy after it's done drying.

It should look something like this:
20121229_121732.JPG



Here's a video showing how it works with my cheap microphone. It works super well to remove almost all noise from my recordings and just needs about a 6db gain and bass-boost adjustment in post-processing for accurate sound reproduction. This could be and will be corrected with a better mic in the future.

 

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Last edited:

QNBT

Senior Member
Oct 14, 2010
1,432
657
Does 1000 ohms apply to USB driven mics (somehow)? Or is it only a matter of drivers? To be specific I'm referring to the Snowball from Blue.
 

Adreaver

Senior Member
Jun 12, 2012
1,516
874
New London
I'm considering adapting this mod to my specific needs. I'm looking to hardwire my lady's car for handsfree using google now. I have headphone audio in via a tape deck adapter. This mod would allow me to add an external mic mounted to the steering wheel or dashboard.

Is the mic functionality of this mod exclusive with audio output? Or could I keep the Red, Blue, and remaining copper wires and attach them to a separate 1/4" jack for audio out?

This would then give me a Y-Adapter, with one side for Mic In, and the other for Line Out.
 

AdamOutler

Retired Senior Recognized Developer
Feb 18, 2011
5,224
9,812
Miami, Fl̨̞̲̟̦̀̈̃͛҃҅͟orida
Does 1000 ohms apply to USB driven mics (somehow)? Or is it only a matter of drivers? To be specific I'm referring to the Snowball from Blue.

If there is a way to configure that chip, its locked away in proprietary drivers. The ohms only affects the pins 1 and 2 in the OP. To my knowledge all samsung camera apps (GCam and Note2 tested) do not have the ability to record bluetooth or USB.
 
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AdamOutler

Retired Senior Recognized Developer
Feb 18, 2011
5,224
9,812
Miami, Fl̨̞̲̟̦̀̈̃͛҃҅͟orida
I'm considering adapting this mod to my specific needs. I'm looking to hardwire my lady's car for handsfree using google now. I have headphone audio in via a tape deck adapter. This mod would allow me to add an external mic mounted to the steering wheel or dashboard.

Is the mic functionality of this mod exclusive with audio output? Or could I keep the Red, Blue, and remaining copper wires and attach them to a separate 1/4" jack for audio out?

This would then give me a Y-Adapter, with one side for Mic In, and the other for Line Out.

It would work well.. to activate Google Now you simply open the connection between pins 1 and 2 momentarily... however, i posted a schematic for the entire audio controls via USB last year. It uses the Built-in FSA chip present in all Samsung Galaxy devices. You bridge USB PINS 4-5 WITH A 410kohm resistor and then using a set of 10 switches and resistors you can seek, skip, pause, and several other actions. The schematic for a car-mode audio dock is located in the USB chip manual.
 
Last edited:

lutadore

New member
Feb 26, 2011
3
1
Adam,

I've found this on the net and thought it may be of interest to you.
These guys have worked on a similar project, but for the iPhone. On the wiki they stated that they couldn't get the android microphone to work, but I think you solved the problem.

I am unable to post links but the project is called BootlegMic, and the wiki is:

wiki dot openmusiclabs dot com slash wiki slash BootlegMic


Regards
Lutadore

Sent from my GT-P3100 using xda app-developers app
Edit: typos fixed
 
Last edited:

darkspr1te

Senior Member
Sep 24, 2012
948
583
Adam,

I've found this on the net and thought it may be of interest to you.
These guys have worked on a similar project, but for the iPhone. On the wiki they stayed that they couldn't get the android microphone to work, but I think you solved the problem.

I am unable to post links but the project is called BootlegMic, and the wiki is:

wiki dot openmusiclabs dot com slash wiki slash BootlegMic


Regards
Lutadore

Sent from my GT-P3100 using xda app-developers app

Sadly this wont work for ifruit devices, due to the fruits closed licence system for 3-rd party products the headphone have to digitally ID themselves to the phone. Take and 4 pin ifruit headset and on the other side of the buttons board is a small ic, it get's it's 1.2v from the earphone signal and transmits digital secure key down the ground/mic wires. Also the fruit company decided to swap ground and mic wires so my ifruit 4 headphones make my note do some very odd things, but put my samsung note phones in the ifruit and all it does is cancel the call.

darkspr1te
 

springer.music

Senior Member
Dec 15, 2010
546
303
Planet Earth
Getting things together
Everything you need to add external, directional audio is available at Radio Shack for less than $35 USD. Buy a better microphone with higher ohms for louder sound. You get what you pay for.
1. 1/4" Mono In-Line Audio Jack (2-pack) - RS Part Number 274-0340 - $5
2. a set of Samsung Earbuds with 4-pole connections
3. optional - microphone Unidirectional Dynamic Microphone - RS Part Number 3303038 - $19.99 - note the old one is 900ohms. The new one is 600 ohms.
4. optional - Biasing Resistor - you will need to do the following equation to determine the ohmage of resistor you require. $5
1100 ohms - (ohms of your microphone stated in the manual) = ohms of resistor required to turn on the microphone.
1100 ohms - 900 ohms = 200 ohms of resistance required
5. Epoxy and Superglue $5

Thanks for the tips but I found that all external mics for iPhone work pretty well with Android devices.

As I mentioned in another thread, I have an irig mic cast and it works like a charm with both my old Galaxy Note (now sold) and with my Galaxy Note 2: http://forum.xda-developers.com/showthread.php?t=1795707

Also it's a condenser mic which should have better sensitivity than a dynamic mic, and it's got a socket to connect a set of earbuds or speakers.

I got it for $39: http://www.bestbuy.com/site/IK+Multimedia+-+iRig+Mic+Cast+Condenser+Microphone+for+Select+Apple%AE+Devices/4755719.p?id=1218522129796&skuId=4755719

There's also a bigger handheld version of the same mic:
http://www.bestbuy.com/site/IK+Multimedia+-+iRig+Handheld+Condenser+Microphone+for+Select+Apple%26%23174%3B+Devices+-+Black/Silver/2938035.p
 

AdamOutler

Retired Senior Recognized Developer
Feb 18, 2011
5,224
9,812
Miami, Fl̨̞̲̟̦̀̈̃͛҃҅͟orida
Thanks for the tips but I found that all external mics for iPhone work pretty well with Android devices.

As I mentioned in another thread, I have an irig mic cast and it works like a charm with both my old Galaxy Note (now sold) and with my Galaxy Note 2: http://forum.xda-developers.com/showthread.php?t=1795707

Also it's a condenser mic which should have better sensitivity than a dynamic mic, and it's got a socket to connect a set of earbuds or speakers.

I got it for $39: http://www.bestbuy.com/site/IK+Multimedia+-+iRig+Mic+Cast+Condenser+Microphone+for+Select+Apple%AE+Devices/4755719.p?id=1218522129796&skuId=4755719

There's also a bigger handheld version of the same mic:
http://www.bestbuy.com/site/IK+Multimedia+-+iRig+Handheld+Condenser+Microphone+for+Select+Apple%26%23174%3B+Devices+-+Black/Silver/2938035.p

I tried an iRig. The guy at Radio Shack opened it up and we tried it. The volume was unusably low.
 

springer.music

Senior Member
Dec 15, 2010
546
303
Planet Earth
I tried an iRig. The guy at Radio Shack opened it up and we tried it. The volume was unusably low.

The iRig as such is a guitar adapter, therefore I don't think it's suitable for mics:
http://www.radioshack.com/product/index.jsp?productId=11976281

iRig mic and iRig mic cast on the other hand are real condenser mics.
The recording volume on mine is loud and clear, it also has a switch to adjust the sensitivity from Low to High (a sort of volume booster).

Most likely the guy at radio shack made you try the wrong product...
 

Adreaver

Senior Member
Jun 12, 2012
1,516
874
New London
The iRig as such is a guitar adapter, therefore I don't think it's suitable for mics:
http://www.radioshack.com/product/index.jsp?productId=11976281

iRig mic and iRig mic cast on the other hand are real condenser mics.
The recording volume on mine is loud and clear, it also has a switch to adjust the sensitivity from Low to High (a sort of volume booster).

Most likely the guy at radio shack made you try the wrong product...

Audio inputs have 2 possible settings: mic or line. Mic uses a hardwired preamp to boost volume to usable levels, where line does not.

While most professional mixers have a switch for each input, since the iRig went for an iDiot-proof solution, you need to buy the correct adapter.

Maybe somebody more motivated than me could solder in a switch with an extra resistor that would allow for a mic/line toggle. Probably easier to get the mic version and disable the preamp for line rather than the other way around.

Edit: http://m.bestbuy.com/m/e/product/detail.jsp?skuId=4770587&pid=1218526674224&ev=prodView is an I rig mic preamp that enables phantom power. Won't allow an all in one solution for mic/line, but should be a hack free way to attach any mic you want.

Sent from my SPH-D710 using xda app-developers app
 
Last edited:

Zkaar

Senior Member
Oct 13, 2012
328
77
I want to do this, but only if it will work on a I9000. The I9000 mic is a piece of crap, so I'm wondering if making this and attach a external mic will solve anything...
 

pravarth

Senior Member
Jul 11, 2011
158
26
Mysore
Great guide, thanks. I want to do the same mod and create a 3.5mm 4 pole to 3.5mm mic and headphone splitter. I want to use to connect a pc headset with mic to blackberry curve 9220. Any idea on how i should go about finding the right impedance for mic and control?
 

Jurassitol

Senior Member
Jul 13, 2012
273
64
I have a 200 Ohm mic, so would this be too much of an impedance jump (given I add an 800 Ohm) for the resistor to have clear audio? Great work by the way, love following your techniques.
 

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  • 30
    Hey guys, I worked on adding external microphone features to my device for a dog-gone long time yesterday... about 5 hours. Elite Recognized Developer Rebellos searched the code and we figured out that the device wouldn't recognize my mic because it's ohms are too low. The WolfsonMicro chip uses any value below 1000 ohms to signify button presses. Above 1000 ohms it signifies a microphone. My microphone is a 900 ohm microphone, so in all actuality, it's pretty high considering most are around 100-500 ohms. However, Rebellos and I managed to hack through it. I wanted to share this method.

    My target device is a Galaxy Camera, but Samsung has used WolfsonMicro chips in their devices for a long time. This also works on the Galaxy Note 2 so Its logical to assume it will work on others.

    Here's the finished solution. A Samsung 4-pole to 1/4" Mic adapter with a 200ohm resistor inline.
    20121229_121732.JPG



    Introduction
    attachment.php


    The Galaxy Camera and Note2 require over 1000 ohms of resistance in order to recognize that a microphone is connected to it. So, there's two ways to do this.

    1. Buy a microphone with over 1000 ohms of impedance.
    2. Add some impedance.

    Now, adding impedance will reduce the volume of the microphone, but that's not an entirely huge issue as adjusting volume is not a big deal. However, adding a resistor will slightly distort the waveform but even with this slight distortion it's not going to destroy the sound quality because it's a very slight ripple which in most cases will not affect the compressed recording quality.

    Getting things together
    Everything you need to add external, directional audio is available at Radio Shack for less than $35 USD. Buy a better microphone with higher ohms for louder sound. You get what you pay for.
    1. 1/4" Mono In-Line Audio Jack (2-pack) - RS Part Number 274-0340 - $5
    2. a set of Samsung Earbuds with 4-pole connections
    3. optional - microphone Unidirectional Dynamic Microphone - RS Part Number 3303038 - $19.99 - note the old one is 900ohms. The new one is 600 ohms.
    4. optional - Biasing Resistor - you will need to do the following equation to determine the ohmage of resistor you require. $5
    1100 ohms - (ohms of your microphone stated in the manual) = ohms of resistor required to turn on the microphone.
    1100 ohms - 900 ohms = 200 ohms of resistance required
    5. Epoxy and Superglue $5

    Building the adapter
    Building the adapter is quite simple Samsung uses 7 wires in their headphones. Bare wire is not connected to anything. 3 are copper colored in clear shields there is a Blue or Green, Red and White as well. The 3 copper are the common leads The White is the microphone.

    1. Cut the connector off the headphone, leaving 3 inches of the cable.
    2. Cut all of the wires except for one Copper and the White wire.
    3. Strip and tin the Copper and White wires.
    4. Solder the copper wire to one side of the 1/4" Mono In-Line Audio Jack
    5. *Optionally* If required to exceed 1100ohms solder the resistor to the white wire
    6. Attatch the white wire (with resistor if used) to the center post of the 1/4" Mono In-Line Audio Jack.
      At this point you can verify your setup works.
      20121229_104711.JPG

    7. superglue the wire to hold it in place for the next step
      20121229_105045.JPG
    8. Mix up your epoxy and apply to the resistor, wire and jack connections in a way to support the following:
      1. to keep the wires from touching anything
      2. to prevent physical strain on the electrical connections
      You'll want to ensure that the epoxy is a light coat which totally surrounds the wire, resistor and large metal pads on the 1/4" audio jack. But don't let it go down inside the jack because it can prevent the microphone from connecting properly.
      20121229_105648.JPG
    9. slide the 1/4" jack cover down over the epoxy after it's done drying.

    It should look something like this:
    20121229_121732.JPG



    Here's a video showing how it works with my cheap microphone. It works super well to remove almost all noise from my recordings and just needs about a 6db gain and bass-boost adjustment in post-processing for accurate sound reproduction. This could be and will be corrected with a better mic in the future.

    2
    So, there's two ways to do this.

    1. Buy a microphone with over 1000 ohms of impedance.
    2. Add some impedance.
    3. Capacitor couple the signal.

    I tried with a 4 conductor plug, a 0.1 µF cap and a Shure SM58.
    Note: A much larger capacitor (~100 µF) is really needed for decent bass response.
    It needed a good 30 dB in Audacity to make a reasonable level.

    You could use a mic mixer, an attenuator and a capacitor to couple audio into your Android.
    Just don't record in .amr format!

    P.S. My ZTE Awe uses 2.5V as bias for the regular FET preamp that would be in a mic.
    1
    Probably could build a preamp circuit using an op-amp to handle the impedance shift without losing volume.
    1
    Does 1000 ohms apply to USB driven mics (somehow)? Or is it only a matter of drivers? To be specific I'm referring to the Snowball from Blue.

    If there is a way to configure that chip, its locked away in proprietary drivers. The ohms only affects the pins 1 and 2 in the OP. To my knowledge all samsung camera apps (GCam and Note2 tested) do not have the ability to record bluetooth or USB.
    1
    I've just seen this:

    CES: IK Mobile Music Accessories Now Compatible with Android
    http://www.ikmultimedia.com/news/?item_id=1982

    and

    CES: Announcing iRig Recorder for Android
    http://www.ikmultimedia.com/news/?item_id=1981

    It was about time! :D

    I rig is very low volume. I've tried it. It sucks.