Nord User Forum

[Eumel]

Hi keyboard colleagues,

I have a very general question and maybe you like to share your opinion with me/us here. To me, the Nord keyboards' latency (time from pressing a key with medium velocity until audio out from the instrument's sockets) is obviously small enough so that it doesn't bother me (NS2EX, NLA1). I remember in the old times, that e.g. the Roland U20 had quite a big latency that hindered me from playing real groovy or perfectly in time. Playing those instruments didn't give me acoustical feedback that was 'direct' enough. This latency topic was not a topic anymore to me in the last 20 years. Now, having bought two synth simulations for my iPad Pro 2015 (iWavestation and the Moog Model D) I'm suffering from that topic again. I am using the original Apple Lightning to USB 3.0 Camera Adapter plus the Thomann MIDI USB 1x1. Did anybody ever measure the latency on any keyboard or synth simulation? Would a newer iPad be faster? How can I overcome that?

What are your experiences with professional emulations like e.g. Keyscape running on a MacBook? What MacBook is needed at least for that? Is such a MacBook comparable to an iPad?

Many questions, many thanks for your comments in advance

Greets

Eumel

[maxpiano]

Hi Eumel, usually it is the Audio that contributes more to the latency rather than the MIDI (even using a MIDI USB adapter; even with standard MIDI DIN the typical max latency to & from a hardware MIDI device is a around 2ms.

So also with the iPad it is crucial to use a good and fast (and compatible) external audio interface, able to work without glitches with lower audio buffers sizes (to keep audio latency below 7-8ms); for example with my iPads I use a Yamaha AG03 and it works pretty well for me, with Camelot (and also other audio apps) I can set the buffer size at 256bytes = 5,8ms of latency at 44.1KHz (less if going at 48KHz). Internal iPad audio latency is higher + it loads the CPU more (since it has to "manage" the internal sound generation logic/settings, like EQ, rather than just sending audio data to the USB Audio card)

[Eumel]

Hi maxpiano,

first of all - many thanks for your prompt answer. To be honest, I do not get it. I think (maybe I'm wrong) that the latency is caused by the iPad, but not by its D/A conversion but by the synth emulation (the iPad is forced to calculate DSP algorithms though the iPad is no specific DSP). The Yamaha AG03 can take over the D/A conversion, ok, but is this really the slow part?

Thanks

Euml

[maxpiano]

Hi maxpiano,

first of all - many thanks for your prompt answer. To be honest, I do not get it. I think (maybe I'm wrong) that the latency is caused by the iPad, but not by its D/A conversion but by the synth emulation (the iPad is forced to calculate DSP algorithms though the iPad is no specific DSP). The Yamaha AG03 can take over the D/A conversion, ok, but is this really the slow part?

Thanks

Euml

The iPad is just executing code (of the synth App you are using) just like a computer running a Virtual Instrument would do (neither a PC or Mac use dedicated DSPs as well) and considering that an iPad can run 3D videogames that re way more complex than a VST then you should see that it is not a CPU performance problem, to a reasonable extent, trust me; I run Ravenscroft 275 or iMini or Sunrizer or iM1 (...) on an iPad Air2 with the buffer settings I mentioned and latency is just the same you'd get using the same VSTs on a PC/Mac (you just need to be less demanding in terms of polyphony, at least on an Air2 but I also have an iPad Pro 2018 and in that case you can ask for more )

Maybe you should also describe better what apps re you using exactly and what the settings.

[anotherscott]

with the iPad it is crucial to use a good and fast (and compatible) external audio interface, able to work without glitches with lower audio buffers sizes

Are you sure about this? The iPad Pro model in question has a headphone out. While there are reasons one might want to use an audio interface, I have not seen evidence that it will improve latency compared to that standard audio output. But I could have missed something.

Getting back to the OP: Some people are more sensitive to different amounts of latency then others are. Unusually, I didn't see a way to adjust buffer size in Model D (and I don't have iWavestation)... you can adjust it if you run it within an AUv3 host, have you tried that? If you didn't need a host app for anything else, I'd be hesitant about adding the overhead of running another program essentially only for the purpose of trying to reduce overhead but it's worth a shot.

Other than that, short of the obvious (running in airplane mode, not running other background apps) I'm not aware of any way to get better performance except to buy an iPad with a faster processor, which can allow you to reliably pick lower buffer settings (for the apps that have that setting), and hopefully, for those apps that make this setting by themselves, they can tell they're on a faster machine and adapt their own settings accordingly.

[maxpiano]

with the iPad it is crucial to use a good and fast (and compatible) external audio interface, able to work without glitches with lower audio buffers sizes

Are you sure about this? The iPad Pro model in question has a headphone out. While there are reasons one might want to use an audio interface, I have not seen evidence that it will improve latency compared to that standard audio output. But I could have missed something.

I can only be sure sure of what I have experienced directly, on an Air2 (which has headphones out as well) testing Rav 275 with the same frequency and buffer settings (44.1KHz and 256) I have observed higher CPU load and as a consequence more frequent glitches when using the internal audio vs using the external USB audio.

PS: OK, maybe it is not "crucial" but "better/recommended"