The purpose of this project is making your favourite audio editing tool into powerful live audio processor. In my case I use Sonar 3 Producer Edition, it is old software but work fine and low computer and resource requirements. Now they launch ver. 7.  Thanks to Eugene V. Muzychenko for his Virtual Audio Cable and Michael Tippach for his ASIO4ALL, because of their software I can make low latency digital audio processor. The latency is about 30 ms, this is almost unhearable delay.

Figure 1. Block Diagram Live Audio Processor Using Audio Editing Software

Figure 1 describe how to turn audio editing software into powerful live audio processor. Music from radio automation software  is inputed to Virtual Audio Cable and audio from outside mixer is inputed to line input your real souncard. The real soundcard and Virtual Audio Cable are wrapped with ASIO4ALL that provide low latency/delay from input to output. Then I use these two soundcard devices as input in the Sonar 3 producer audio track. After some audio processing, I send the output to real soundcard then to stereo encoder / transmitter and the other to VAC 2 as monitor. For the monitor I use N-Track software as audio spectrum analyzer.

Before set-up everything you should install Zararadio Automation Software, ASIO4ALL , Virtual Audio Cable, N-track and Sonar 3 Producer Edition. After install all software, you should set like shown below :

Figure 2. Real Soundcard Recording Setting

Figure 2 is real soundcard recording settings. Go to Control Panel>>Sounds and Audio Devices>>Device Volume>>Advanced>>Option>>Properties>>Choose Recording and select Line In as recording device.

Figure 3. Virtual Audio Cable Setting Setting

Figure 3 is settings for Virtual Audio Cable. Go to Virtual Audio Cable control panel to set 2 VAC sound devices.

Figure 4. ASIO4ALL Setting

Figure 4 is ASIO4All settings. Go to ASIO4ALL Ofline Setting  I set 512 samples for real soundcard ASIO buffer. It is will cause about 10 ms latency/delay. And I set 256 samples for VAC (5 ms latency). Then I activated Always Resampled 44.1 kHz<->48kHz on both of them.

Figure 5. ZaraRadio Automation Sofware Setting

Figure 5 is Zararadio settings. Go to Tools->Options->Output

Figure 6. Sonar 3 Producer Edition

Figure 6 is Sonar 3 Producer Edition worksheet. Sonar is multi-tracks audio video editing software and only support Direct-X Plugin. You will need Cakewalk VST Adapter to load your favourite VST Plug-in to DirectX plugin. For starting point, you should set audio device in Sonar, Go to Options>>Audio>>Advanced Tap>> Choose Asio for Driver Mode and enable write and read caching then go to General Tap>>Set Playback Timing Master to
ASIO4All Your Real Soundcard and Set RecordTiming Master to ASIO4All Virtual Cable 11. The details shown below :

Figure 7. Sonar Audio Devices Setting

Figure 8. Sonar Audio Devices Setting

Figure 9. Sonar Audio Devices Setting

After set the audio devices, insert some audio tracks and some buses as your need. In my case I need 3 tracks and 3 buses, one track for Zararadio, one for microphone from mixer 1,  one for microphone from mixer 2, one bus for Musics, one bus for microphones and one bus for master. In Sonar every track and bus are provided by equalyzer automatically. With this equalizer you can make 16 kHz brickwall Low Pass Filter (LPF).You can enable this feature as your need. 

Figure 10. Audio Routing in SONAR 3

After that, set Zararadio track input to Stereo ASIO4ALL Virtual Cable 11 and Microphones tracks input to Stereo ASIO4ALL Your Soundcard 11. The output is set to Musics bus for Zararadio and Microphones bus for microphone. These are important to break into two buses because different audio treatment between musics and human speeches. Insert your favourite VST or Direct-X plugin into effect boxes. 

The output for Musics and Michrophones buses are set to Master bus. The output for Master is set to ASIO4ALL Your Soundcard 1. I insert send to ASIO4ALL Virtual Cable 2 into Master bus for N-Track Spectrum Analyzer.

Now Turn On Echo in every track (->) symbol.

Happy Transmitting