pspsounds wrote:Anybody had experience with both and which is better?
I've recently made this exact switch so I'm plenty qualified to comment on it.
Everything I write is merely my opinion of using both, even though I have used the 2500 much more extensively... just bare that in mind. Regardless of which OS you use with the 2500, there's still a number of features the 4K has that the 2500 can't touch and never will.
There's the obvious things like a sequencer with 10 times more resolution, 24/96 sampling engine, 64 note poly, MUCH more flexible and useable filters, and the effects are
actually pretty decent for Akai. You also get buttons for all the main functions (even a button for every letter of the alphabet for easy naming), and thus far I have not discovered any tucked away hidden functions. A bonus in my book.
There's also great build quality, the adat option which I seriously rate (nice one Gertie

), a bigger screen and a jog wheel that doesn't drive you nuts!
On the downside... with
my 4K the pads are rubbish! I have to set the sensitivity to 200% to get anywhere close to an acceptable level of playability. There's plenty of options for making them better, but at this point I miss the 2500's pad response. Even without any twonkery I could still play the pads on the 2500 like I was typing on a keyboard, whereas on the 4K I have to roll my sleeves up and stand over it. It's not the end of the world though. The screen changes are also a wee bit sluggish compared to the 2500, but various other modes offset that in usefulness with the extra real estate. Sequence Edit (grid edit) is particularly good IMO. Q-link implementation and the way you edit them is night and day over the 2500.
JJ also has a number of great features that the 4K will never have.
NDC is cool, as are a whole raft of functions to speed up workflow and add power. You should peruse the comparison charts if you aren't familiar with it.
The issue I have with JJ is the OS is in constant flux... more so now than at any point with the new screen. If you miss a few updates when you eventually load the latest OS there's a bunch of extra shit on the main screen that leaves you thinking "WTF??", as well as other "refinements" that take time to learn. I can't be doing with any of that shite now. There's plenty of bug testers on here who will help push the OS, but the bottom line is the 1K and 2500 will never have the horsepower that
I truly need.
A word on sound quality...
The 4K and 2500 are in a similar league of possessing a very transparent sounding output. No obvious coloration... BUT, if you start adjusting the pitch and/or heavily layering you start to hear a distinct improvement with the 4K. Especially working at 24 bit. As a full keygroup sampler this is where the 4K comes into its own. It's either important to you or it doesn't matter. It matters to me.
If you search out any sound comparisons on here or anywhere else, you will often find a single drum loop or synth sound is used as a basis for a serious test of sound quality. Bullshit! If a test doesn't comprise a multi-tracked and layered audio file then it's useless at determining what has the greater fidelity. Again, this is either important to you or it isn't.
AKsys is another bonus of the 4K, assuming you can get it to work. On the latest Windows and Mac OS's it's a no-go, but using VMware Fusion in either one of those it becomes a worthwhile tool. It will enable you to manage the files on your 4K's hard drive , as well as create programs and keygroups. It gets the job done.
The sequencer timing is also reported to be the most solid of any hardware sequencer ever made.
Almost sample accurate... a deviation of fractions of a millisecond. The 'Litmus Test' used to confirm this is a widely regarded benchmark of accuracy.
Hope some of this helps...
