Doors just opened. It's still the warm-up in here. Grab your spot and check back as the floor fills up.

B2B Beta
Menu

Set up your sound

Numark Scratch · Behringer UMC204HD

Check my kit

Check your computer, DJ software and gear work with DJ back 2 back before you sign up. It takes a minute, and nothing you pick is kept.

Your computer

Not sure? On a Mac: Apple menu → About This Mac. On Windows: Settings → System → About.

Its system

Wiring: computer, Behringer UMC204HD, Numark Scratch, powered speakers or amp, headphonesComputerUSBBehringerUMC204HDUSB (USB-B)inputs 1-2(XLR/TRS combo)outputs 1-2 (RCA)outputs 3-4 (RCA)Numark ScratchMaster Out (RCA)Line/Phono Inputs (RCA)Headphone Outputs(6.35 mm / 3.5 mm)Powered speakersor ampHeadphonesUSB-B to USB-C, orUSB-B to USB-ARCA to jack (¼")RCA to RCARCA to XLR, orRCA to jack (¼"), orRCA to RCA

Plug your headphones into your mixer or controller, not your computer.

FromToCable
Behringer UMC204HDUSBComputerUSBUSB-B to USB-C, or USB-B to USB-A
Numark ScratchMaster OutBehringer UMC204HDInputs 1-2RCA to jack (¼")
Behringer UMC204HDOutputs 1-2Numark ScratchLine/Phono InputsRCA to RCA
Behringer UMC204HDOutputs 3-4Powered speakers or ampRCA to XLR, or RCA to jack (¼"), or RCA to RCA
Numark ScratchHeadphone OutputsHeadphones

Your gear

Standalone controller

Your model

Numark Scratch

It has what the app needs, but we haven't tried it yet.

  1. Connect the Scratch's Master Out to your interface's inputs 1-2. That's your mix.
  2. Connect your interface's outputs 1-2 to the Scratch's Line/Phono Inputs, and set its Line/Phono Selector to Line and that deck's Deck Input Selector to Line/Phono. That channel is your partner's fader.
  3. Plug your headphones into the Scratch's Headphone Outputs, and cue your partner's channel there to beatmatch them.
  4. Keep your master level up: your partner hears your mix through it.
  5. If your speakers are on outputs 3-4: in Audio MIDI Setup, select your interface, click Configure Speakers, and set it to Quadraphonic, so this Mac sees 4 outputs.
  6. At Your sound in and out: under Source, pick your interface with Source channels 1-2; under Line in, the same with Line in channels 1-2; under Speakers out, where your speakers are plugged in.

PA or Mains

  • On a Mac: Powered speakers: run a cable from your Mac's output (or your audio interface's outputs) straight into the speakers.
  • On Windows: Run a cable from your PC's or interface's output straight into your powered speakers.
  • An amp and speakers: run the same cable into the amp's input. The amp drives your speakers as usual.
  • To check, in your first session: while you play, your track should sound once and clean. Once your partner has taken over, only your speakers play their set. When they hand back, it's back on your mixer ready to beatmatch. Nothing of them: your speakers are on your master out. Your own track doubled while you play: both are connected.

Interfaces that suit this setup

This setup needs an audio interface with two line inputs (for your mix) and two outputs (for your partner). If it has four outputs, your speakers can go on outputs 3-4. If it has two, plug your speakers into your computer.

  • On Windows: Outputs listed as OUT 1-2 and OUT 3-4? Line in on OUT 1-2.
  • On Windows: Speakers on OUT 3-4.
  • On Windows: Never pick a Loopback input as Source.

Behringer UMC204HD · 2 inputs (XLR/TRS combo) and 4 outputs.

Tested by us

Cables: one pair from your Numark Scratch's Master Out to the interface's inputs 1-2 (your mix), and one pair from the interface's outputs 1-2 to your Numark Scratch's Line/Phono Inputs (your partner). With the Behringer UMC204HD:

  • Numark Scratch Master Out (RCA) → Behringer UMC204HD inputs 1-2: RCA to jack (¼")
  • Behringer UMC204HD outputs 1-2 (RCA) → Numark Scratch Line/Phono Inputs: RCA to RCA

Check what comes in the box. If these cables aren't in it, you'll need to buy them.

In a set, the app shows these buttons and messages: READY · Set starts in · Handover · Accept handover · Confirm partner is mixed out · Fader up.

  • When offered a handover, make sure your partner's fader is up, then click Accept and mix in your track.
  • You have control. Once you're in, confirm your partner is mixed out.
  • When you're ready, you hand over, your partner accepts and tells you when you're mixed out, and you can stop your track.

Tested on Windows

Only gear that passed our Windows test:

  • Behringer UMC204HD: main and headphones on OUT 1-4.
  • MOTU M4: headphones on MOTU M Series (ASIO).
  • Pioneer DJM-V10: your partner on the channel set to USB 1/2.

VirtualDJ on Windows

No 4-channel output, such as the MOTU M4:

  1. Click the gear (top right).
  2. Click AUDIO.
  3. Under OUTPUTS, click SPEAKER + HEADPHONE.
  4. Under master, pick your interface's Out 1-2 (WASAPI). VirtualDJ's Audio Settings, with the master's list open and Out 1-2 (MOTU M Series) (WASAPI) picked.
  5. Click APPLY.
  6. Pick chan 1 & 2.
  7. Click APPLY.
  8. Under headphones, pick your interface's ASIO entry.
  9. Pick Out 3 & 4.
  10. Click APPLY. VirtualDJ's Audio Settings, finished: master on Out 1-2 (MOTU M Series) (WASAPI), chan 1 and 2; headphones on MOTU M Series (ASIO), Out 3 and 4.

4-channel output, such as OUT 1-4? Set master and headphones both to it: chan 1 & 2, then chan 3 & 4.

rekordbox on Windows

  1. Open Preferences.
  2. Click Audio.
  3. On Configuration, open the Audio list.
  4. Under Windows Audio, pick your interface's Out 1-2, not an ASIO entry: our app hears nothing from ASIO. rekordbox's Preferences, Audio, with the Audio list open: Out 1-2 (MOTU M Series) picked under Windows Audio, above the ASIO entries.
  5. Check that Audio shows Out 1-2. rekordbox's Preferences, Audio, finished: Audio on Out 1-2 (MOTU M Series), 48000 Hz, 256 samples.

Serato DJ Pro on Windows

Without Serato hardware, Serato DJ Pro plays to Windows' own output:

  1. Open Windows Settings, then System, then Sound.
  2. Under Output, pick your interface's Out 1-2. Windows' Sound settings, under Output: Out 1-2 (MOTU M Series) picked, the default device.
  3. In Serato DJ Pro, turn the master down until our "Your sound level" bar sits level with its mark, not past it. Serato starts at −0.1 dBFS, which pins the bar.

Your internet

Use a wired connection wherever possible.

Upload speed: 5 Mbps or more, or quality may drop.

How a set sounds depends on both DJs' internet connections, which we don't control. We can't promise a connection will be good enough.

Any issues? Email support@djb2b.com