The aXRotate plugin receives an update today to version 1.2.0 and it’s a big one! What’s more, it now comes as a (Universal Binary) AudioUnit format for Mac!
If you have already bought it, you can download the update from the download section of your Account page. If you haven’t, you can pick it up at my online shop!
Version 1.0.0 was a plain vanilla Ambisonics rotation with yaw, pitch and roll control. Version 1.2.0 adds two new features that massively increase its usefulness:
- Get head tracking by connect an EDTracker module.
- Increase the spaciousness of your static binaural mixes by adding micro oscillations to the sound scene.
Let’s go into both of these new features in a bit more detail.
Head Tracking Inside Your DAW
There are a lot of ways to improve how your Ambisonics mix will sound but, if you’re listening to a binaural rendering, head tracking has got to be the most dramatic (tied with HRTF personalisation).
aXRotate can now receive data directly from the EDTracker, which is a low cost, efficient head tracker. It come in both wired and wireless versions. If you want to spend even less, there is a DIY solution for less than £10!
When your EDTracker is already connected and you add a new instance of aXRotate to your project, it should connect automatically. If it does not, or you connect the EDTracker after adding the plugin, you can simply click on the Connect button.
The Rezero button resets the front-facing position to the orientation of the tracker when the button is pressed. This is useful if you want to change what direction you’re facing while working, or even if you just want to readjust the position of your headphones!
Increased Spaciousness Without Tracking
People don’t tend to keep their head perfectly still. They will make tiny involuntary head movements. aXRotate allows you to simulate these head movements. This is most useful for when you are creating a static binaural rendering, as it can increase the perceive spaciousness of the scene. Is it a substitute for real head tracking? No. Is it one more thing you can do to improve the quality of your production. Sure.
Micro Head Movements can be activated from the drop-down menu in the bottom half of the plugin interface, to a maximum of 10 degrees. The oscillation amplitude you pick will depend on your audio content. The aim is to have as small variations that are not audible or distracting, just like real micro head movements.
Micro Head Movements are disabled automatically when head-tracking is active because in this case the micro-movements are in the tracker movement data!
A Note On Latency…
Latency is a critical factor when it comes to head tracking. To avoid perceptual artefacts, the head tracking latency needs to be as low as possible.
A major component in this is your audio interface buffer size. If you make a head movement it cannot be reflect in the audio until at least the buffer has finished processing and is output by your audio interface. You should set your audio interface latency to as low as possible without causing audio drop-outs.
Be aware that convolutions also add latency to the signal. Therefore, you should aim to only have your Ambisonics-to-binaural render after the aXRotate.
Convolutions placed before the aXRotate will add latency to the audio, but not to the head tracking.
You should aim for a total latency of less than 50 ms. The shorter, the better.
Update Rate
The Update Rate controls how often the head tracker is sampled or micro head movements are updated. This value must always be smaller than your audio interface buffer size.
Smaller update values will lead to smoother head-tracker/movement data but will require more CPU.
Note that the Update Rate only controls how often the data is sampled, it does not change the overall latency! As mentioned, reducing your audio interface buffer size will do that.
The Future of aXRotate
I want to add support for more head trackers in the future. Get in touch with me to tell me what head tracker you are using and I will see if it is possible to provide support for it directly inside aXRotate.
For now, if you want to support future development you can purchase the aXRotate for up to first, third or seventh order from my web store. Thanks!
