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Live-Mode Step by Step Guide
This guide will introduce you to another major feature of the program. As before, follow along with the included demo file and perform the actions printed in Bold type. We assume you have mastered the other concepts we introduced in the Basic and Advanced audio restoration Step by Step guides. Please make sure you have completed those earlier guides before attempting this one even if you are a Forensics User. It teaches you the basic flow of the software program.
Live-mode is a powerful feature of DCArt10 / DCForensics10 that allows you to remove noise and enhance audio as it happens. You do not have to record the audio to the hard disk before applying filters. Live Mode is used by TV and Radio broadcast engineers to clean up noisy live feeds for real-time transmission. Forensics users use it to clean up real-time surveillance audio streams. It is also useful for cleaning up radio reception for Hams, SWLs, DXers, and other Forensic applications. Audiophiles sometimes use Live mode to replace the preamplifier and tone controls in their audio system. If you have your computer connected to your home stereo, you can use Live-mode to actually restore your records while you play them. It can also be used “on site” by Forensic users who may need to listen to (and record) surveillance audio as it happens.
To use Live-mode, make sure you have your speakers connected to the sound card output and an audio signal connected to the line level input. This audio signal source can be from a soundboard, mixer, radio receiver (or tuner), turntable (with preamp) or any other signal. For this Step-by-Step guide, we’re going to assume you are using a radio to provide a signal to the program. In this case, you would connect the headphone or other audio output of your radio or tuner to the Line Input of your sound card.
Turn on the radio and you should hear audio from the speakers connected to your computer. This step depends somewhat on the brand and model of sound card that you have, but the great majority of sound cards will simply take whatever audio appears on its input and sends it directly to the output of the sound card. If you don’t hear anything, just keep going in this Guide, as we’ll check everything out a bit later.
Now turn off your Radio and launch the program if you haven’t already and then open the file called “Radiodemo.wav”. It’s in the same directory as the other demo files. Before we do this live, we’re going to experiment a bit with a recorded bit of audio.
Once the file is loaded, listen to it. You can hear that there is A LOT of noise in this file. It is understandable, but would not be fun to listen to due to all the noise. Once the file has finished playing, open the Multi-Filter (under the Filter Menu) and choose the preset called “Live Mode Demo Cleanup – SW Radio”. This preset provides some useful tools for this demonstration file. This preset will also be a good starting point for your own efforts as you use the program in Live mode.
Double click the Continuous Noise Filter to open its adjustment window. You can look at the settings for all the tools in the Multi-Filter preset and you should be able to understand what they are doing based on your learning so far. Remember, you can always open a specific filter and then hit F1 to find out about it. Your screen should look something like this:
Multiple Screens Shown Working Together
We want to bring your attention specifically to the Continuous Noise filter here because we are dealing with a concept that you might not have considered – How do I use this filter in Live mode when I can’t take a sample of the noise? Remember, the audio is happening in real time and is typically not recorded to the disk at all in Live-mode. It’ll therefore be impossible under these conditions to actually take a noise sample. Our preset setting here shows how you can deal with this. Notice that the filter is set to provide a fairly large amount of attenuation to the low frequencies and the higher frequencies (remember, the higher the blue square controls are set, the more noise is removed at that frequency). With radio signals, we will seldom care about very low or very high frequencies anyway, so this setting gets rid of a lot of noise without unduly bothering our good signal. The controls between 300 Hz and 3,000 Hz (which are speech frequencies) were then simply adjusted for good results. Go ahead and hit the Multi-Filter Preview button now. Click Bypass in and out to hear the improvement. (Alternatively, change the CNF mode of the Continuous Noise Filter to Auto Spectrum CNF or AFDF and the filter will find its own noise fingerprint on-the-fly.)
Notice the slider labeled Attenuation. This control determines the overall amount of filtering that is going on for the entire filter. If you move this control upwards, it will filter more overall noise. While Previewing, adjust the attenuation slider to find the point you like best. You’ll find that this very weak signal is now quite understandable – if you speak German. The other filters are also adjustable, of course. You’ll quickly find that there is a tradeoff here. The more aggressive you make the Continuous Noise filter, the more digital artifacts you will induce. Just adjust it to please your ears.
Now stop the Preview and let’s go into Live-mode. Turn on your radio so that you can hear the signal in your computer speakers.
Note: If you don’t hear anything, continue on anyway as some sound cards don’t monitor incoming audio by default. Double click the leftmost icon in the Multi-Filter so that you can adjust your audio settings. Do that and then click on the button labeled “Live Preview” and the program will immediately start providing filtered audio to your speakers. You should certainly be hearing audio now.
In the Live-mode, your screen should look something like this figure:
Live-Mode is engaged
Important -- Do you hear two versions of the audio – one a bit later in time than the other - like an echo effect? If so, you need to turn down the input of your sound card. If you have a standard sound card, just double click the speaker icon in your tray and choose “Options” then “Properties”. Now click on “Recording” and then click “OK”. Now move the slider labeled Line Input or Line down to the bottom. The echo should go away! If you have a more sophisticated sound card, refer to its documentation to find out how to turn off monitoring or turn down the Line Input control.
If you have the DC Forensics10 version of the program, you cannot only process audio in real time, but you can record it as well. Just click the Log to Disk button. Additionally, you can also select VOX recording (the program starts and stops recording automatically with the signal that comes in) and have the program mark the segments with the date and time of their occurrence.
Here’s a tip. You can now add or change the filters as you please. A good one for radio work is the Dynamic Processor using the ALC mode. This can help a lot with atmospheric fading in a SW (Short Wave) signal as it will even out the audio level in real time.
What you have learned:
In this Step-by-Step Guide, you’ve learned how to use the Multi-Filter in Live mode to process audio as it happens. You’ve learned how to adjust your sound card for Live-mode – remember, however, that some low quality sound cards cannot record and play at the same time and therefore can’t be used in Live Mode. You’ve also learned how some filters can be used to make radio reception much better.
This guide will introduce you to another major feature of the program. As before, follow along with the included demo file and perform the actions printed in Bold type. We assume you have mastered the other concepts we introduced in the Basic and Advanced audio restoration Step by Step guides. Please make sure you have completed those earlier guides before attempting this one even if you are a Forensics User. It teaches you the basic flow of the software program.
Live-mode is a powerful feature of DCArt10 / DCForensics10 that allows you to remove noise and enhance audio as it happens. You do not have to record the audio to the hard disk before applying filters. Live Mode is used by TV and Radio broadcast engineers to clean up noisy live feeds for real-time transmission. Forensics users use it to clean up real-time surveillance audio streams. It is also useful for cleaning up radio reception for Hams, SWLs, DXers, and other Forensic applications. Audiophiles sometimes use Live mode to replace the preamplifier and tone controls in their audio system. If you have your computer connected to your home stereo, you can use Live-mode to actually restore your records while you play them. It can also be used “on site” by Forensic users who may need to listen to (and record) surveillance audio as it happens.
To use Live-mode, make sure you have your speakers connected to the sound card output and an audio signal connected to the line level input. This audio signal source can be from a soundboard, mixer, radio receiver (or tuner), turntable (with preamp) or any other signal. For this Step-by-Step guide, we’re going to assume you are using a radio to provide a signal to the program. In this case, you would connect the headphone or other audio output of your radio or tuner to the Line Input of your sound card.
Turn on the radio and you should hear audio from the speakers connected to your computer. This step depends somewhat on the brand and model of sound card that you have, but the great majority of sound cards will simply take whatever audio appears on its input and sends it directly to the output of the sound card. If you don’t hear anything, just keep going in this Guide, as we’ll check everything out a bit later.
Now turn off your Radio and launch the program if you haven’t already and then open the file called “Radiodemo.wav”. It’s in the same directory as the other demo files. Before we do this live, we’re going to experiment a bit with a recorded bit of audio.
Once the file is loaded, listen to it. You can hear that there is A LOT of noise in this file. It is understandable, but would not be fun to listen to due to all the noise. Once the file has finished playing, open the Multi-Filter (under the Filter Menu) and choose the preset called “Live Mode Demo Cleanup – SW Radio”. This preset provides some useful tools for this demonstration file. This preset will also be a good starting point for your own efforts as you use the program in Live mode.
Double click the Continuous Noise Filter to open its adjustment window. You can look at the settings for all the tools in the Multi-Filter preset and you should be able to understand what they are doing based on your learning so far. Remember, you can always open a specific filter and then hit F1 to find out about it. Your screen should look something like this:
Multiple Screens Shown Working Together
We want to bring your attention specifically to the Continuous Noise filter here because we are dealing with a concept that you might not have considered – How do I use this filter in Live mode when I can’t take a sample of the noise? Remember, the audio is happening in real time and is typically not recorded to the disk at all in Live-mode. It’ll therefore be impossible under these conditions to actually take a noise sample. Our preset setting here shows how you can deal with this. Notice that the filter is set to provide a fairly large amount of attenuation to the low frequencies and the higher frequencies (remember, the higher the blue square controls are set, the more noise is removed at that frequency). With radio signals, we will seldom care about very low or very high frequencies anyway, so this setting gets rid of a lot of noise without unduly bothering our good signal. The controls between 300 Hz and 3,000 Hz (which are speech frequencies) were then simply adjusted for good results. Go ahead and hit the Multi-Filter Preview button now. Click Bypass in and out to hear the improvement. (Alternatively, change the CNF mode of the Continuous Noise Filter to Auto Spectrum CNF or AFDF and the filter will find its own noise fingerprint on-the-fly.)
Notice the slider labeled Attenuation. This control determines the overall amount of filtering that is going on for the entire filter. If you move this control upwards, it will filter more overall noise. While Previewing, adjust the attenuation slider to find the point you like best. You’ll find that this very weak signal is now quite understandable – if you speak German. The other filters are also adjustable, of course. You’ll quickly find that there is a tradeoff here. The more aggressive you make the Continuous Noise filter, the more digital artifacts you will induce. Just adjust it to please your ears.
Now stop the Preview and let’s go into Live-mode. Turn on your radio so that you can hear the signal in your computer speakers.
Note: If you don’t hear anything, continue on anyway as some sound cards don’t monitor incoming audio by default. Double click the leftmost icon in the Multi-Filter so that you can adjust your audio settings. Do that and then click on the button labeled “Live Preview” and the program will immediately start providing filtered audio to your speakers. You should certainly be hearing audio now.
In the Live-mode, your screen should look something like this figure:
Live-Mode is engaged
Important -- Do you hear two versions of the audio – one a bit later in time than the other - like an echo effect? If so, you need to turn down the input of your sound card. If you have a standard sound card, just double click the speaker icon in your tray and choose “Options” then “Properties”. Now click on “Recording” and then click “OK”. Now move the slider labeled Line Input or Line down to the bottom. The echo should go away! If you have a more sophisticated sound card, refer to its documentation to find out how to turn off monitoring or turn down the Line Input control.
If you have the DC Forensics10 version of the program, you cannot only process audio in real time, but you can record it as well. Just click the Log to Disk button. Additionally, you can also select VOX recording (the program starts and stops recording automatically with the signal that comes in) and have the program mark the segments with the date and time of their occurrence.
Here’s a tip. You can now add or change the filters as you please. A good one for radio work is the Dynamic Processor using the ALC mode. This can help a lot with atmospheric fading in a SW (Short Wave) signal as it will even out the audio level in real time.
What you have learned:
In this Step-by-Step Guide, you’ve learned how to use the Multi-Filter in Live mode to process audio as it happens. You’ve learned how to adjust your sound card for Live-mode – remember, however, that some low quality sound cards cannot record and play at the same time and therefore can’t be used in Live Mode. You’ve also learned how some filters can be used to make radio reception much better.