Microphone quality is bad!

Hi,

Recorded audio with unity3d microphone API in android have low quality.i made a microphone plugin in java for unity android and recorded an audio but have very good quality.

What is the problem?
java code plugin:

public static void StartRecording()
    {
   		FreeRecorder();
   		
   		File sampleDir = Environment.getExternalStorageDirectory();
   	    try 
   	    {
   	      audiofile = File.createTempFile("sound", ".wav", sampleDir);
   	    }
   	    catch (IOException e) 
   	    {
   	      Log.e(TAG_Recorde, "sdcard access error");
   	      return;
   	    }
   	    mRecorder = new MediaRecorder();
   	    mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
   	    mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
   	    mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_WB);
   	    mRecorder.setOutputFile(audiofile.getAbsolutePath());   		
        mRecorder.setOnErrorListener(errorListener);
        mRecorder.setOnInfoListener(infoListener);
        
        try 
        {
            mRecorder.prepare();
            mRecorder.start();
        }
        catch (IllegalStateException e) 
        {
            e.printStackTrace();
        }
        catch (IOException e) 
        {
            e.printStackTrace();
        }
        
        Log.d(TAG_Recorde , "Start Recording!");
    }

Unity code:

    private void StartMic()
    {
        clip = Microphone.Start(Mics[0], true, 15, 24000);
    }

Thanks.

hi Milad,
I have same problem

so after a long time, do you solve it?