DJM900NXS2 Pitch effect has noticeable artifacts

Not sure if I'd really classify what you're hearing as "quantizing," rather, it's granular affect which is essentially the internal DSP filling in the "gaps" caused by stretching linear audio it's processing beyond its relative means–a similar occurrence found with granular synthesis. I digress.

Back on topic, there's always going to be sonic artifacts when adjusting music in a destructive manner, in this case pitching up/down. The question is: when do these artifacts become noticeable for you (cite values)? Are they occurring with slight pitch adjustments or only when utilizing extreme settings? These specifics, in addition to some (audio samples) would really aid your chances for receiving proper assistance.

Also, because I have to ask, have you updated to the most recent firmware and do these artifacts occur on compressed and uncompressed songs?

I can understand stretching audio creating gaps but our algorithms have also gotten very good at filling in those gaps to create seamless transitions across those gaps with little to no noticeable artifacts. Native Instrument's traktor's key transpose settings are an example of this. I can basically transpose something up an entire octave and hear no sonic artifacts. I can do the same thing when transposing it down an octave.

Also- the artifacts that i'm referring to are when I'm pitching things both up and down. What it really sounds like is similar to the little pops that can be heard when you have an audio buffer set too low on a soundcard and the soundcard gets overloaded and the buffer backs up and drops bytes. It's a bunch of subtle drop-outs. The reason I use the term "quantize" is because generally when audio is re-pitched in this manner, there's some level of chopping of the audio that's going on in order to uniformly "fill in the gaps" so to speak.

In my particular case, I have a song in Abm that i want to pitch up to Am. That's a single semitone. First off, pitching it up should not be creating gaps in the audio signal. But even further, pitching it up by only a single semitone should not be creating little sonic artifacts like what appear to be drops out overflowing of the buffer.

Also- recent firmware up to date and compression of the audio files should not make a difference- these transpose just fine with traktor in real time without such sonic artifacts.

Perfect–thanks for the clarification.

Honestly, I think the Pitch FX on the mixer is designed more for a performance effect as opposed to utilizing for continuous playback such as adjusting the pitch of a track on a turntable/CDJ.

That said, the pops that you're hearing does sound like a viable concern, there should be no CPU issues since all processing is handled directly within the hardware's DSP. @Pulse or one of his partners in crime are better suited to help you troubleshoot from this point out. The clarification you provided above, however, will definitely be helpful.

I would be inclined to agree with you about being a performance mixer but this seems to occur with ANY use of the pitch effect, not just long-term pitching. The artifacts are present during any use of the effect and it seems like some of the other effects cause it too. This makes me really think that the mixer being overloaded and the DSP engine is not able to keep up w/ the audio stream.

Even without a CPU on board, DSP chips are still doing signal processing on digital bytes. Can they not still get overloaded?

Thank you by the way for your responses! They are definitely appreciated and it's nice to know someone else is actually looking at these posts.

@Corey > How much are you pitching the audio?

The Pitch effect sounds awful on the XDJ-RX2 (standalone mode) too (yes, I realize this is an old post, but it's still happening).  I honestly think there is a bug in Pioneer's pitch shifting implementation.  I say this because Master Tempo sounds good (even over pretty large tempo changes) and using the pitch fader without using Master Tempo also sounds all right. Shouldn't pitch shifting just be a combination of the two? (Pitch it up as if with the pitch fader, then slow it down as if with Master Tempo.)

EDIT: it sounds awful at even 1% pitch change. Slightly less bad if Level/Depth is way down, but it's not really possible to get it to usable settings.

I hate pitch-shifting things. Master Tempo has varied across products over the years (many claim the best was the CDJ-1000MK3), but I've only ever been happy sticking under 6% (one semi-tone). I can't say with any certainty, but I feel as if the pitch effect uses a different algorithm than the master tempo processing, as it does seem to create more artifacting at 4% than MT does at 8%.

Honestly, I would consider the pitch effect just that -- an effect; not a function.

@Pulse I think you're right that the algorithm is currently completely different.  I understand that pitch shifting is a very tough problem that can't be solved perfectly in general.  Changing the pitch by whole percentage points isn't really going to be precise enough to use it for key changes anyway.  My complaint is more that right now it sounds bad enough it's hard to use even as an effect