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Flacbox 1.6: Auto Sync, Equalizer, OPUS Support

Flacbox 1.6: Auto Sync, Equalizer, OPUS Support

Anna Kosenko
Anna Kosenko Co-Founder & Director at Everappz

Flacbox 1.6 brings major new features to the FLAC music player for iPhone and iPad.

TL;DR: This update adds automatic cloud library sync, a 10-band equalizer with custom presets, OPUS format support, and the ability to play music from external SD cards. A FLAC playback bug has also been fixed.

What’s New in Flacbox 1.6

Automatic Cloud Music Library Sync

No more manually refreshing your library. The new sync engine automatically scans selected cloud folders and updates your music library in real time.

  • Enable via: Settings → Music Library → Automatic Sync
  • Select folders via Sync Folder → Change Settings
  • Choose sync mode: Wi-Fi only or Wi-Fi + Cellular
  • Enable Background Sync for auto-updates while the player is active (increases battery usage)

Your cloud music collection stays current without manual intervention.

10-Band Equalizer for Custom Sound

Shape your audio with the built-in 10-band equalizer, accessible from the Player screen or Settings.

  • Adjust frequencies between -12 dB and +12 dB
  • Use built-in presets or create your own
  • Fine-tune preamp power (use caution to protect hearing)

This gives you studio-level audio control on your iPhone or iPad.

OPUS File Format Support

Flacbox now plays OPUS files alongside FLAC, ALAC, MP3, and other formats. OPUS is a high-efficiency codec used widely for voice and music. Full equalizer support is included for OPUS playback.

Play Music from External SD Cards

Play music directly from an SD or microSD card connected to your iPhone or iPad:

  • Use a Lightning to SD Card Camera Reader Adapter
  • Insert the card and connect to your device
  • Open Flacbox – it recognizes the card automatically
  • Browse and play files via the Services → PowerDrive section

This is ideal for expanding your music library without using device storage.

FLAC Playback Bug Fix

A 2-second skip at the end of FLAC files has been fully resolved. Tracks now play seamlessly from start to finish.

Download Flacbox

Flacbox 1.6 is available now on the App Store. Download Flacbox and try these features today.

Have feedback or feature requests? Reach out – we build Flacbox based on what our users need.

Frequently Asked Questions

What audio formats does Flacbox support?
Flacbox supports FLAC, ALAC, MP3, AAC, OGG, OPUS, WAV, AIFF, DSD, and other popular audio formats. All formats work with the built-in equalizer.
Can I play music from an SD card on my iPhone?
Yes. Connect an SD or microSD card using a Lightning to SD Card Camera Reader Adapter. Flacbox detects the card automatically and lets you browse and play files directly from external storage.
Does Flacbox sync with cloud storage automatically?
Yes. Starting with version 1.6, Flacbox can automatically sync your music library from cloud folders. Enable Automatic Sync in Settings and select the folders you want to monitor.
Is the Flacbox equalizer customizable?
Yes. The 10-band equalizer lets you adjust individual frequency levels between -12 dB and +12 dB. You can use built-in presets or save your own custom settings.
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