This tool is a simple utility for adjusting the volume (gain) of WAV/FLAC/ALAC files. You can increase or decrease the volume in the range of -10dB to +10dB. It adjusts only the gain while completely preserving the original file format (bit depth and sampling rate).
✨ Key Features
Simple Operation - Just drag and drop files and enter the adjustment gain value (+1.0, -1.5, etc.)
Multiple File Support - Process single or multiple files simultaneously
Individual Gain Settings - Specify different gain values for each file
Auto Clipping Adjustment - Automatically processes with maximum safe gain when clipping is detected
Metadata Preservation - Complete preservation of tag information and cover images
3 Format Support - Supports WAV/FLAC/ALAC (.m4a)
Gain Range - Adjustment from -10dB to +10dB
📌 Important Notes
ALAC Processing: Processing ALAC (.m4a) files requires ffmpeg (PATH registration or placement in the same folder as EXE)
Original File Protection: Original files are never modified. Adjusted files are created as new files
📦 Distributed Files
File Name
Description
gain_adjuster.exe
Executable file (approx. 22MB)
gain_adjuster_ReadMe.html
User manual (Japanese version)
gain_adjuster_ReadMe_en.html
User manual (this file - English version)
Note: This tool requires no installation. Simply place the EXE file in any location to use it.
📋 System Requirements
Item
Details
OS
Windows 10 or later
WAV/FLAC Processing
Works standalone (no additional software required)
ALAC Processing
Requires ffmpeg (PATH registration or placement in same folder)
About ffmpeg (for ALAC processing)
To process ALAC (.m4a) files, ffmpeg is required:
Method 1: Register ffmpeg in system PATH (recommended)
Method 2: Place ffmpeg.exe in the same folder as gain_adjuster.exe
Processing: Convert to WAV via ffmpeg for processing
🚀 How to Use
Basic Usage
Drag and drop audio files (single or multiple) onto gain_adjuster.exe
Console window opens and displays the number of files
Enter gain adjustment value for each file (e.g., -2.5 or +3.0)
Press Enter to start processing
When processing is complete, new files are created in the same location as the original files
After all files are processed, a summary is displayed
💡 Gain Value Input Examples:
-2.5 - Decrease by 2.5dB
+3.0 - Increase by 3.0dB
1.5 - Increase by 1.5dB (+ sign can be omitted)
-5dB - Decrease by 5dB (dB notation also acceptable)
Multiple File Processing Example
Found 3 valid file(s)
============================================================
File 1/3: song1.wav
Enter gain adjustment value: -1.5
✓ Completed successfully
File 2/3: song2.flac
Enter gain adjustment value: +2.0
WARNING: Clipping detected at +2.0dB!
Auto-adjusting to maximum safe gain: +1.2dB
✓ Completed with auto-adjusted gain (+1.2dB)
File 3/3: song3.m4a
Enter gain adjustment value: +0.5
✓ Completed successfully
SUMMARY
============================================================
Processed: 3/3 files
Auto-adjusted files:
- song2.flac: +2.0dB → +1.2dB
📊 Processing Specifications
Item
Specification
Gain Adjustment Range
-10dB to +10dB
Clipping Protection
Yes (auto detection & auto adjustment)
Metadata
Complete preservation (including tags and cover images)
📁 Output Files
Processed files are saved with the following naming convention:
File Name Examples
Original file:music.wav
After -2.5dB adjustment:music_-2.5dB.wav
After +3.0dB adjustment:music_+3.0dB.wav
Output Examples by Format
WAV:original_+2.0dB.wav
FLAC:original_-1.5dB.flac
ALAC:original_+3.0dB.m4a
⚠️ Auto Clipping Adjustment Feature
If clipping (audio distortion) would occur due to excessive gain increase, the tool automatically processes with the maximum safe gain value.
Auto Clipping Adjustment Example
Enter gain adjustment value: +5.0
Processing...
WARNING: Clipping detected at +5.0dB!
Peak level would be: +2.35dB over 0dBFS
Auto-adjusting to maximum safe gain: +2.5dB
Peak level: 0.998 (OK)
✓ Completed with auto-adjusted gain (+2.5dB)
Benefits:
Completely avoids clipping
Applies the highest possible gain
No need to re-run
Processing does not stop midway
❓ Troubleshooting
"ffmpeg not found" error (during ALAC processing)
Cause: ffmpeg is not found for ALAC (.m4a) file processing.
Solution:
Register ffmpeg in system PATH
Or place ffmpeg.exe in the same folder as gain_adjuster.exe
Processing is slow
Causes and Solutions:
ALAC processing: Takes longer than other formats due to ffmpeg conversion (normal operation)
Large files: Processing time is proportional to file size
Multiple files: Sequential processing takes file count × processing time
🎓 Technical Specifications
Gain Calculation: Accurate volume adjustment using linear gain (10^(dB/20))
Processing Precision: High-precision processing with float64 (double precision floating point)
Audio Quality Degradation: Theoretically no quality degradation due to processing at same bit depth and sampling rate
🔒 Security Information
⚠️ About First Run Warning
Windows Defender (SmartScreen) may display a warning, but this is a false positive:
"Windows protected your PC" is displayed
Click "More info"
Click "Run anyway" button
📄 Disclaimer
Notes on Use
Use of this tool is at your own risk.
The developer assumes no responsibility for any changes or loss of audio quality resulting from audio file processing.
For commercial use, please comply with relevant copyright laws and license agreements.
The developer assumes no responsibility for any damage caused by the operation of this tool.
This tool was developed to provide music enthusiasts with a better music experience.
If you have any questions or feedback, please feel free to contact us using the above information.
Audio Gain Adjuster - Universal Audio Volume Adjustment Tool