Tech, Art, DIY, invention #IPPParadigm: Adding external Microphone to Android tablet or SmartPhone

Many Android devices ( smartphones , tablets, etc. ) are great for filming events and people. You can improve your videos by using an external microphone. The most important part of a typical video is high quality sound. More important than the lighting or focus or .......

I performed most of these experiments on a Samsung Galaxy Avant smartphone circa May 2015.

Choosing a microphone
Many microphones will work with a android device. The key issue is to have a microphone that puts out an active signal ( not to exceed 1 volt ). Some microphones produce an active voltage. Some require a battery ( voltage source ) to do so.
Many computer microphones ( that plug into a 3.5mm jack ) depend on the computer supplying a voltage for operation. See images at the end of this post.
A dynamic microphone produces a voltage without any external voltage sources. I experimented with a AKG-D70-ME.
A condensor microphone requires an external voltage source. I experimented with an un-named condensor microphone I found in my junk box.

Getting the correct adapter cable
You will want to buy an adapter cable with a 3.5mm audio jack with 4 connections on it ( TRRS: tip-ring-ring-shield ). See image at end of this post. There are two versions of this, so make sure to get the correct version. I bought mine at MicroCenter.com for $5. You can get them on eBay. Make sure the TRRS is ear-ear-ground-microphone ( iPhone compatible ) .

Testing your tablet or smartphone
Plug in the adapter cable to the Android device ( headphone jack ). Plug your microphone into the adapter cable. Plug your headphones into the adapter cable. Use an audio sound recorder application. My phone indicated that an external microphone was activated. ( This does not prove the microphone is working. ) Try recording and speak into the microphone. Try different distances and speaking levels. Try windscreens and pop screens. At each test announce what you are testing. Example: " I am 3 inches from microphone .... testing the black windscreen. I am speaking loudly."

Adjusting the sound level
Sound level applications are available at the online Android Apps Store ........ many good ones are free. Using the app you can adjust the sound level of your microphone.
1) by the distance the microphone is from the subject
2) by muffling the microphone with soft foam
3) your microphone may have a signal level adjustment. ( Or you may be rich and be using a mixer )
4) editing the sound later .... using a video editing application. There are many to choose from ( many are free ) I choose to move videos to my Apple MacIntosh to edit.

Avoiding hum and wind noise.
Cables must be shielded. Using a balanced microphone cable is advised.
Putting a pop filter and/or windscreen on a microphone can improve the sound quality. You can make ( DIY do it yourself ) these easily using soft foam or even thick fabric.

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Images

Microphones come in a myriad of sizes and shapes. You cannot tell what kind a microphone is just by looking at it.