def _start(self):
                if self.config['source'] == 'pulse':
                        proc_mm = subprocess.Popen(
                                ['multimon-ng', '-a', 'AFSK1200', '-A', '-t', 'raw', '/dev/stdin'],
                                stdout=subprocess.PIPE, stderr=open('/dev/null')
                        )
                else:
                        if self.config['source'] == 'rtl':
                                proc_src = subprocess.Popen(
                                        ['rtl_fm', '-f', str(int(self.config['rtl']['freq'] * 1e6)), '-s', '22050',
                                        '-p', str(self.config['rtl']['ppm']), '-g', str(self.config['rtl']['gain']$
                                        stdout=subprocess.PIPE, stderr=open('/dev/null')
                                )
                        elif self.config['source'] == 'alsa':
                                proc_src = subprocess.Popen(
                                        ['arecord', '-D', self.config['alsa']['device'],
                                        '-r', '22050', '-f', 'S16_LE', '-t', 'raw', '-c', '1', '-'],
                                        stdout=subprocess.PIPE, stderr=open('/dev/null')
                                )
                        proc_mm = subprocess.Popen(
                                ['multimon-ng', '-a', 'AFSK1200', '-A', '-t', 'raw', '/dev/stdin', '-'],
                                stdin=proc_src.stdout,
                                stdout=subprocess.PIPE, stderr=open('/dev/null')
                        )
                        self.subprocs['src'] = proc_src
                self.subprocs['mm'] = proc_mm