# DDJ-FLX4 - map Crossfader FX Toggle to Smart Fader button **URL:** \ **Category:** DJ Hardware\ **Tags:** macOS, iOS\ **Created:** [January 23, 2024, 7:44pm UTC](https://community.algoriddim.com/t/ddj-flx4-map-crossfader-fx-toggle-to-smart-fader-button/23996 "2024-01-23T19:44:04Z")\ **Posts on this page:** 1\ **Page:** 2
**Author:** ![Slak\_Jaw](https://community.algoriddim.com/user_avatar/community.algoriddim.com/slak_jaw/32/6517_2.png) [@Slak\_Jaw](https://community.algoriddim.com/u/Slak_Jaw)\ **Post date:** [October 8, 2026, 7:04pm UTC](https://community.algoriddim.com/t/ddj-flx4-map-crossfader-fx-toggle-to-smart-fader-button/23996/24 "2026-10-08T19:04:26Z")
Hi @djchase, the Smart Fader button isn’t locked down anymore. Also, you can easily MIDI map an unused button to the Crossfader FX toggle yourself: 1. Go to **Dashboard \> Settings \> MIDI Devices** and tap your DDJ-FLX4. 2. Press an unused button or SHIFT+ the desired button on the FLX4 3. Set the Target to **Mixer** and the Action to **Crossfader FX Toggle**. 4. Tap **Save** and give it a new name so you keep the original mapping as a backup. ![IMG_1325](https://community-assets.algoriddim.com/original/3X/5/5/553d4c05a2b8b5232581dc4e28ca17c36557bbab.jpeg) If Crossfader FX Toggle doesn’t show up in that list, or it saves but the button does nothing, let me know exactly what you see and I’ll dig into it. I hope that helps! If you’ve never used the MIDI Learn tool in djay before, please refer to the section linked below from the user manual. > **[Mapping a MIDI device | Algoriddim Support](https://help.algoriddim.com/user-manual/djay-ios/midi/mapping)** > > If your controller isn’t natively supported, you can still use it with djay’s MIDI Learn feature. This lets you map hardware controls directly to djay functions on your iOS device. You can also edit the mapping of supported controllers to customize... [Previous page](https://community.algoriddim.com/t/ddj-flx4-map-crossfader-fx-toggle-to-smart-fader-button/23996.md?page=1)