Confused about tempo slider when 4 deck in sync

I’m trying to find out how the tempo sliders work when I’m using all 4 decks on my Reloop Mixon 8 Pro, using djay pro on my iPad, sync enabled on all 4 decks.

It looks like moving the slider up and down only sometimes changes the tempo on a deck, but I cannot tell what the logic is.

What I have tried:

  1. Load a different song on each of the 4 decks.
  2. Click sync on each of the decks.

First question, how do I know which deck is the “main” deck that all the other 3 decks will sync the BPM to?

  1. Load a new song on deck 2.
  2. After a second or two, the BPM on the deck 2 is in sync.
  3. Now I move the tempo slider on deck two down, but nothing changes on the display and I can hear the song isn’t changing BPMs.
  4. Then I go back up and somewhere near the middle, it starts updating the BPM.

But sometimes, as soon as I move the tempo slider, the BPMs change. I think this might be related to picking the slider that adjusts the master/main deck, but like my previous question, how do I tell the deck that is the primary?

I recorded a short video showing what I mean, any help would be great!


@fmpwizard this behaviour of the Tempo Faders is actually intentional and necessary to prevent a sudden jump of the Tempo.

  1. To better understand how this works, switch from 4 DECK Display Mode to CLASSIC Display Mode in djay. This will display the Tempo Faders on the screen.
  2. Set the Tempo Fader in the center for Deck 1 on the Mixon 8 and press Play.
  3. Make sure Sync is Off and adjust the Tempo of Deck 2 by moving the Tempo Fader well away from Center then press Play on Deck 2.
  4. Now press Sync on Deck 2. You will notice that the on screen Tempo Fader moves to match the BPM of Deck 1, but the physical position of the Tempo Fader on the Mixon 8 no longer matches it.
  5. To prevent a sudden jump in Tempo, the Fader will not affect the software Tempo until you move the physical Fader on the Mixon 8 to match the position on the screen.
  6. In 2 Deck Mode you will actually notice the “ghost” fader position on the screen (see below).
  7. Once the physical Tempo Fader position on the Mixon 8 matches the position in the software you will have control over the Tempo again.
  8. Unfortunately, there is currently no Tempo Fader display option in djay in 4 Deck Mode.
  9. Basically, you need to move the Tempo Fader Up or Down on the Mixon 8 until you find the position in the software.

@fmpwizard regarding your Master Tempo question, I recommend you first read the support article below on how the two different types of Sync work in djay depending on your settings.

Now for the harder part. Honestly, I’ve been using djay for many years and I’m still not 100% sure how the Master Deck is determined. Again, I suggest you experiment with 2 Deck Mode first to get a better sense of how it works. I’ll explain my experience with 3 common scenarios:

SCENARIO 1: No Decks Playing

  1. With Sync OFF and 2 new tracks loaded into Deck 1 and Deck 2.
  2. The Deck that you press the Sync button ON becomes the Slave and the other becomes the Master.
  3. For example, if you press Sync on Deck 1, Deck 2 becomes the Master Deck.

SCENARIO 2: Two Decks Playing

  1. This is basically the same a Scenario 1, but with the both Decks already playing.
  2. With Sync OFF and 2 new tracks loaded and Playing on Deck 1 and Deck 2.
  3. The Deck that you press the Sync button ON becomes the Slave and the other becomes the Master.

SCENARIO 3: One Deck Playing

  1. By default, I believe the actively playing Deck is the Master. So the Deck that is Playing through the master out and the audience can hear (ie. Channel Fader and Cross Fader Open).
  2. Pressing Play and the Sync Button on either Deck 1 or Deck 2 will Sync it to the one that was Playing first. For example, Deck 1 is playing through the main speakers and Deck 2 is paused with a new track. If you press Sync on Deck 1 or on Deck 2, Deck 2 will Sync to Deck 1 because it’s already playing and is considered the Master Deck.
  3. I believe the first Deck remains the Master Deck until you stop playback and load another track onto that Deck.
  4. In this case, the other Deck that is now actively Playing with the Channel Fader Open and Cross Fader side Open becomes the new Master Deck.

Now this all gets a bit more complicated with 4 Decks, but this should point you in the right direction for your own experimentation.

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Thank you so much for the replies! The link you provided and the explanation of the “ghost” fader really helped.
I’ll play around with the master deck portion of the question, I really wish the app would somehow highlight the master deck, when I’m in the middle of a chain of tracks, it’s hard to keep all of this in my head and still mix.

@fmpwizard you’re welcome. Glad that helped.

If you’d like to make a request to have a Master Deck Indicator added to the software, you can create a separate post on the Suggestions area. This way other users can up vote it and Algoriddim can get a sense of the demand.

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