The DJM-900NXS2 adds a second USB port at the top of the unit for connecting a second laptop for quick changes, as well as an 1/8″ headphone jack (yes, you can finally leave those 1/4″ adapters at home).
The Sound Color FX now has a «Min/Max» parameter knob like the DJM2000 for even more tweaking, chunkier knobs, and a new effect called «Sweep». There’s also a redesigned Beat FX section, which now has a sharp OLED display, a bigger touchpad, and new effects including Ping Pong delay, Vinyl Brake, and «Helix».
You can also specify which frequencies are affected by these effects through the FX Frequency selector (eg when you want to add reverb or delay to only high frequencies without touching the low end, for instance). Plus each channel now has a blue LED that tells you which ones are being sent through the Beat FX.
On the tech side, the DJM-900NXS2 sports a 64-bit audio processor (bumped up from 32 in the DJM-900NXS), and has an independent send/return FX channel for hooking up outboard effect processors like Pioneer DJ’s own RMX-500, or even your iPad running an effects app (the RMX1000 comes to mind) and layer them on top of the mixer’s built-in Beat FX. There’s also an added peak limiter, which minimises distortion in the master output when it’s being pushed.