Sound comes out of my headphones or speakers incorrectly. [rekordbox]

There are 3 things to consider: settings, operation and connection.
Please check each in the following sequence:

1) Confirm the audio output destination setting
1. Open rekordbox Preferences.
2. Click [Audio].
3. Check that each item is selected as follows:

■ Windows
Audio: DJM-V10 ASIO
Mixer Mode: External
Output Deck1 :DJM-V10 ASIO: CH1
Output Deck2: DJM-V10 ASIO: CH2
Output Deck3: DJM-V10 ASIO: CH3
Output Deck4: DJM-V10 ASIO: CH4
Output Sampler Deck: DJM-V10 ASIO: SAMPLER VOL

■ Mac
Audio: DJM-V10
Mixer Mode: External
Output Deck1:DJM-V10: CH1
Output Deck2:DJM-V10: CH2
Output Deck3:DJM-V10: CH3
Output Deck4:DJM-V10: CH4
Output Sampler Deck: DJM-V10: SAMPLER VOL

*If you can’t select the correct choice because it isn’t displayed or an error has occurred etc., refer to [Troubleshooting -rekordbox > "I can't set [AUDIO] in the rekordbox Preferences correctly."]

2) Check the volume level operation
1. Play a track.
2. Set the [TRIM] knob to the center (12 o’clock).
3. Slide the channel fader to the top.
4. Slide the crossfader to the center.
5. Turn the MASTER [LEVEL] knob to 2 o'clock.
If the MASTER [LEVEL] indicator lights up more than half way, there’s no problem in the settings and operation.
If you don’t hear any sound from the headphones at this point, check the following:
6. Turn the [MIX] knob for HEADPHONES A/B to the center.
7. Turn the [LEVEL] knob for HEADPHONES A/B all the way to the left.
8. Press the MASTER [CUE] button.
9. Turn the HEADPHONES A/B [LEVEL] knob slowly to the right.

3) Check the connection of speakers and headphones
For details, see [Connections] in the Instruction Manual.
Even if you’ve already connected them, reconnect them to make sure they’re properly connected.
You can read the Instruction Manual [here].

Note: The DJM-V10-LF doesn't have a crossfader. You can control the volume depending on the scale of the channel fader.