Latency Expectations?

[simoneves]

Dear All,

New MegaDrum owner here. Barely had a chance to play with it yet; just fetched my Roland TD-9 module and PD-105 snare pad from storage and did some basic tests.

I am using Addictive Drums 2 on a 2012 Dell Latitude E6330 laptop (3.0GHz i7, 8GB, USB3.0, new SSD, fresh install of Windows 10 Home, power-saving features disabled in BIOS) with a Zoom UAC-2 USB3.0 audio/MIDI interface and the latest 1.21 Zoom driver installed (which is supposed to be an ASIO driver, or at least can operate in ASIO mode too).

I am wondering what I should be expecting in terms of latency from this set-up?

I hooked up another computer and USB audio interface with a mic into one channel and line-out from the Roland or Zoom into the other, and recorded some hits using Audacity.

Just using the Roland module, I see a latency of ~4ms between the physical hit and its audio out. This is actually more than I expected, but I guess that's as good as it gets for 10yo hardware, and I have never considered it to be unresponsive.

I then hooked up the Roland MIDI out (it doesn't have USB MIDI) to the Zoom MIDI in, with AD2 on the Windows laptop and audio back out through the Zoom, but the latency was TERRIBLE... of the order of 55-60ms.

I then tried the MegaDrum (default config, snare pad into Input 4), MegaDrum Basic map selected in AD2, but the latency was pretty much exactly the same.

I then realized that I was using the default Windows Audio driver mode for the Zoom, and tried switching to ASIO in the AD2 settings, but it refused... just said "failed to initialize device". I tried rebooting but it made no difference, neither did uninstalling and reinstalling the Zoom driver.

I then tried installing ASIO4ALL, which showed up in AD2 as an alternative ASIO driver (it still refused to let me pick the Zoom one) but this was also a failure. I couldn't find any setting that gave clean audio, and although drum hits gave a digital splat with much lower latency, the actual drum sound still didn't start until the 55-60ms mark! I uninstalled ASIO4ALL again.

Getting worried now, I moved the Zoom and AD2 over to my 2012 Macbook Pro (USB2) and then everything was much better. The latency was ~9ms using the TD-9 and MIDI, and ~7ms with the MegaDrum. This was just using the default CoreAudio driver, even though Zoom provide a Mac driver too (which I have not tried; not sure why/if it would be any better).

So, obviously there's a problem with the Zoom driver on my Windows laptop, which I will have to deal with separately, although if there's anyone on here that has one and can help with that, it would be much appreciated.

More concerning is that the MegaDrum is "only" 2ms faster than the Roland with MIDI. Not that I think 7ms is particularly poor, although I am hopeful that this could be improved further. I'm actually more surprised that the Roland wasn't even slower, given that it has to communicate through old-skool 31.25kbit MIDI.

I'm going to try AD2 and the Zoom on my desktop PC next to see if the ASIO driver works on that.

What other sources of latency could be removed or optimized? Is the AD2 Standalone Player the best option, or should I run it as a plug-in inside something else?

Thoughts on any or all of the above gratefully received...

[dmitri]

Latency over standard MIDI will not be noticeably higher then over USB if higher at all - MIDI packets are very short and even over a slower standard MIDI it will add not more than 1-2ms latency. Most of the latency will come from sound synth and this is where you should be trying to reduce it if you're having problems with latency. Good ASIO2 drivers for low latency on Windows is a must. And of course Mac OS (Core Audio) is known for providing better (lower) latency then Windows.

[simoneves]

Fair enough. Thanks, Dmitri.

That's why I specifically bought the Zoom UAC-2, because I was led to believe it was one of the lowest-latency interfaces. I guess their driver just doesn't like my computer, though.

I'll try it on my desktop PC, and I'll try other audio software on the laptop to see if anything else can talk to the ASIO driver. I have a support ticket into XLN with the same questions.

If I have to use the Mac instead, then so be it.

[simoneves]

For the record, it turns out that I had the "Class Compliant" switch on the back of the (new to me) Zoom enabled, which is supposed to allow it to work with iPads etc., but was presumably stopping the Windows ASIO driver from working.

Once I turned this off, the Windows ASIO driver worked as expected, and I was able to get a similar ~7-9ms latency on that platform, depending on trigger input.

Interestingly, having that switch off stopped the Mac from seeing the Zoom until I installed the custom driver on that too. The latency was the same with either Mac driver, though.

[Rovalo]

Also note that the set buffer size in your device ASIO driver highly affects latency.

You can use a latency monitor utility to see which other devices/drivers kill you latency performance, especially network drivers do.