NCH Switch reduces MP3 file sizes primarily by re-encoding them at a lower bitrate, which discards some audio data for smaller files, though this may affect quality.
Steps to Reduce MP3 Size
Launch Switch and click "Add Files" to select your MP3s. Right-click a file, choose an MP3 output format, and adjust settings like bitrate (e.g., lower from 320kbps to 128kbps), sample rate (e.g., 44.1kHz), or channels (stereo to mono).
Click "Convert" to process; output files save to a designated folder with reduced size based on your compression choices.
Key Settings for Compression
Bitrate: Use CBR (constant) or VBR (variable) modes, e.g., -settings .mp3 CBR 128 via command line for 128kbps.
Quality: Set 0-9 (lower for smaller files).
Batch Processing: Add multiple files for efficiency.
Lower settings yield smaller files but potential quality loss; test samples first.