[Skip to bottom for solution if you're not interested in background info]
So, I'm going to try to avoid making this too technical, so I'll start at with some background.

I'm currently a student in university studying Electrical Engineering and moonlighting as a software developer on research programs. As such, I'm often required to be in the beta programs for different pieces of software, on of which is OSX itself. [Current patch: 10.11.4 Beta (15E39d)]

I hadn't gotten the chance to dig out my controller for months because of work, but when I finally could, I found it didnt work.

After trying the regular troubleshooting steps (different USB cables, uninstalling Serato and reinstalling it, checking the Audio MIDI Devices page, installing Serato on a clean install of OSX, etc), I finally broke down and contacted Serato's support team. After going through many of the steps I'd already half tried, I was told that the issue may have something to do with how the operating system is parsing -reading in from hardware- the name of the DJ mixer itself, which is why when I would connect it Serato would begin picking it up and then suddenly drop it with a "failed to connect audio" error at the bottom.

It wasn't until the CS rep was able to talk with the program developers themselves that this revealed itself. And it only took navigating to the Audio Devices page in Audio MIDI Setup to confirm this. Where the name of the controller should have been "PIONEER DDJ-SB" it was instead listed as "PIONEER DDJ_SB". This underscore is what was disallowing communication between Serato and the Controller itself.

So, now that I knew the problem, I went about looking for a way to fix it. The CS rep wisely advised against this, as it can indeed be dangerous to mess around with core system settings, but luckily the fix turned out much simpler than that!

I originally began looking for ways to change the name of the device itself. This led me to Apple's Developer site, and a thing called the "Apple AppleUSBFTDI kernel driver". This ended up being some what of a dead end, but eventually led me to the tools needed to properly probe system Input Output (IO for short) devices.

The software I ended up using to do this was IORegisteryExplorer 3.0.3, which allowed me to get the actual firmware level name of the controller itself. However, when I did so, I found it was actually polling correctly! It said "PIONEER DDJ-SB" just like it should!

This is good news! It meant that the underlying driver of the laptop itself was operating correctly, and that it was something at a relatively high level that was screwing with Serato.


So after that I went back into Audio MIDI Devices and began looking for a way to just change the name of the controller there. Unfortunately, I couldn't find one; but while searching online for a way to do so, I found a forum post about creating what are called "Aggregate Devices". That gave me an idea, 'what if I just create a new device and name it "PIONEER DDJ-SB"'? So I did just that. And it worked!!!



***SOLUTION BEGINS HERE***
[MAKE SURE CONTROLLER IS PLUGGED IN TO COMPUTER AND POWERED ON]

1. Open "Audio MIDI Devices"
2. Go to "Window" on the top bar and click "Show Audio Devices"
3. Click the little "+" button in the bottom left corner and click "Create Aggregate Device" from the drop down
4. Select your controller from the list
5. Double click on the name area where it says "Aggregate Device" (on the left panel showing all devices) and rename it to whatever your controller's name should be. (you should be able to find this in the Audio MIDI Setup panel that shows a bubble chart of all devices)
6. Give the device the proper name
7. Open Serato to confirm it worked
8. Get playing!



Sorry about the lack of pictures, unfortunately you cant upload them on this forum. Hopefully I'll have a guide up soon if people want one that has the pictures.