Audio Recorder with Auto-Silence Detection and Input Monitoring

Professional audio recorder with manual hotkey control, automatic silence-based recording, and input monitoring for capturing audio from Traktor Audio 6 (or any audio interface).

Features

• Input Monitoring (ARM): Monitor your input in real-time through your speakers/headphones before recording
• Silence Trimming: Automatically remove silence from the beginning and/or end of recordings
• Manual Recording: Start/stop with F9/F10 hotkeys
• Auto-Record Mode: Automatically starts recording when audio is detected after silence, stops when silence returns
• Real-time Level Meters: Visual feedback of input levels for left and right channels
• Professional Format: Records WAV files at 44.1kHz, 24-bit stereo
• Configurable Silence Detection: Adjustable threshold (dB) and duration
• Auto-naming: Sequential file numbering with timestamps
• Device Selection: Choose separate input and output devices
• RX11 Integration: Optionally auto-open recordings in iZotope RX11

Installation

1. Install Python 3.8 or higher
2. Install dependencies:

pip install -r audio_recorder_requirements.txt

Note: The keyboard module requires administrator/root privileges for global hotkeys on some systems. If hotkeys don't work, run the script with elevated permissions.

Monitoring Latency

When using ARM (input monitoring), you may experience a small delay (latency) between your input and what you hear. This is normal and depends on:

• Your audio interface drivers (ASIO drivers typically have lowest latency)
• System performance
• Buffer size (blocksize in the code - currently 2048 samples ≈ 46ms at 44.1kHz)

For lower latency:

• Use ASIO drivers if available (Windows)
• Close other applications
• If you experience crackling, the latency is too low for your system

Recording latency: The recorded audio is perfectly in sync - only the monitoring has latency.

Usage

Basic Operation

1. Run the recorder:

python audio_recorder_sil.py

2. Select your input device (Traktor Audio 6 Input B should be auto-selected if connected)
3. Select your output device (for monitoring - can be Traktor Output or your system speakers)
4. Choose output folder and file naming preferences
5. Use ARM feature and recording modes:

ARM (Input Monitoring)

The ARM feature lets you monitor (hear) your input in real-time before recording - essential for checking levels and making sure everything sounds right.

To enable monitoring:

1. Check "🎧 ARM (Enable Input Monitoring)"
2. Adjust monitor volume (slider)
3. You'll now hear your input through the selected output device
4. Status shows "ARMED - Monitoring Input"

Note: You can be armed without recording (to check levels), or record without being armed (if you don't need to hear the input).

Manual Mode (Default)

• Press F9 to start recording
• Press F10 to stop recording
• Files are saved with sequential numbering + timestamp

Auto-Record Mode

1. Enable "Auto-Record" checkbox
2. Adjust silence threshold (default: -40 dB)
3. Adjust silence duration (default: 2 seconds)
4. The recorder will:
   • Wait for audio above threshold
   • Start recording automatically
   • Stop when silence duration is reached
   • Perfect for recording vinyl, cassettes, or multi-track sessions

Silence Trimming

The recorder can automatically remove silence from your recordings before saving:

Trim from Beginning: Removes all silence before the first sound

• Useful when you hit record before the audio starts
• Eliminates pre-roll silence in auto-record mode

Trim from End: Removes all silence after the last sound

• Cleans up recordings that captured silence after the music stopped
• Perfect for auto-record mode

Trim Threshold: The dB level below which audio is considered "silence"

• Default: -50 dB (quieter than the auto-record threshold)
• Lower values (e.g., -60 dB) = more aggressive trimming
• Higher values (e.g., -40 dB) = only trim very quiet sections

Example: If you record a song with 2 seconds of silence before it starts and 3 seconds after it ends, enabling both trim options will save just the song itself.

Note: The console will print how much silence was trimmed, e.g., "Trimmed 4.23s of silence (original: 184.50s, final: 180.27s)"

Settings Explained

• Silence Threshold: Audio level (in dB) below which is considered silence

  • Lower values (e.g., -50 dB) = more sensitive (detects quieter sounds)
  • Higher values (e.g., -30 dB) = less sensitive (only louder sounds trigger)

• Silence Duration: How many seconds of continuous silence before stopping

  • Useful for avoiding premature stops during quiet passages
  • Typical: 2-3 seconds for music with pauses

• Min Recording Duration: Prevents very short recordings from being saved

RX11 Integration Options

Option 1: Auto-Open in RX11 (Recommended)

Modify the save_recording method to automatically open files in RX11:

# After saving the file, add:
import subprocess
rx11_path = r"C:\Program Files\iZotope\RX 11\RX 11 Audio Editor.exe"
subprocess.Popen([rx11_path, self.current_filename])

Option 2: Batch Processing with RX11

If you have specific RX11 processing chains you want to apply:

1. Save all recordings first
2. In RX11, use Batch Processor:
   • File → Batch Processor
   • Add your recording folder
   • Apply your processing chain (noise reduction, EQ, etc.)
   • Process all files at once

Option 3: RX11 Command Line (Advanced)

RX11 has limited command-line support. Check documentation for:

# Example (syntax may vary):
"C:\Program Files\iZotope\RX 11\RX 11 Audio Editor.exe" -process "preset.rxp" "input.wav"

Workflow Example: Vinyl Ripping

1. Connect turntable to Traktor Audio 6 Input B
2. Select Traktor Input B Left/Right as input device
3. Select your speakers/headphones as output device
4. Enable ARM to hear the turntable
5. Adjust monitor volume to comfortable level
6. Enable Auto-Record mode
7. Set silence threshold to -45 dB
8. Set silence duration to 3 seconds
9. Optionally enable "Auto-open in RX11"
10. Start your vinyl record
11. Recorder automatically creates separate files for each track
12. Listen in real-time as it records
13. Files open in RX11 automatically for:

• Click/pop removal
• De-noising
• Leveling
• Export to MP3/FLAC

Troubleshooting

"No audio device selected"

• Click "Refresh Devices"
• Ensure Traktor Audio 6 is connected and recognized by your OS
• Check that drivers are installed

Hotkeys not working

• Run script as administrator (Windows) or with sudo (Linux/Mac)
• Or use the GUI buttons instead

Audio clipping/distortion

• Check input levels in Traktor/system settings
• Ensure levels stay in the green/yellow range (not red)
• If clipping in monitors, reduce monitor volume

Can't hear monitoring when armed

• Check output device is correct
• Verify output device isn't muted in system settings
• Increase monitor volume slider
• Make sure ARM checkbox is enabled (status should show "ARMED")

Crackling/dropouts when monitoring

• Latency is too low for your system
• Close other applications
• Consider using ASIO drivers (Windows)
• In code, increase blocksize from 2048 to 4096 or 8192

Auto-record starts/stops erratically

• Adjust silence threshold (try -45 dB or lower)
• Increase silence duration to 3-4 seconds
• Check for background noise/hum

File Format

All recordings are saved as:

• Format: WAV (PCM)
• Sample Rate: 44,100 Hz
• Bit Depth: 24-bit
• Channels: Stereo (2)

This format provides excellent quality for archival and is compatible with all audio editing software.

Tips

1. Use ARM to check levels first: Enable monitoring before recording to verify everything sounds right
2. Monitor volume: Keep monitor volume at 50-70% to avoid feedback if using speakers
3. Test your levels: Record a short test before long sessions
4. Watch the meters: Green is good, yellow is okay, red means clipping
5. Use auto-mode for multi-track: Perfect for albums or tapes
6. Manual mode for single takes: When you know exactly when to start/stop
7. Save settings persist: Your preferences are saved between sessions
8. Headphones recommended: Use headphones for monitoring to avoid feedback

Integration with Video Converter

After recording, use the MP3-to-YouTube converter to create videos:

1. Convert WAV to MP3 if needed (or use WAV directly)
2. Choose a static image or video
3. Create YouTube-ready video file

License

Free to use and modify for personal and commercial projects.