Audio Mixing in Pro Tools on the Surface Pro Tablet


When my manager asked me to write a piece about pro audio mixing on a tablet, my curiosity was piqued. My past experiences in tablet-based music production have been exercises in lateral thinking, calling for me to adapt to tablet-specific DAW software, and forgo the use of my favorite professional plug-ins. However, as he told me more about the assignment, it became apparent that I wouldn't be faced with either of these challenges, because I wouldn’t be mixing on just any tablet, I'd be mixing on a Surface Pro tablet running Windows 10 Professional powered by a 1.9 GHz Intel® Core™ i7-8650U Quad-Core processor with turbo boost up to 4.2 GHz, an optional keyboard, and an electronic pen.

Microsoft 12.3" Multi-Touch Surface Pro 6

Naturally, my first thoughts were "Hmm... I wonder if I can I get Pro Tools running on this thing?” and “…what about my Waves plug-ins?" Considering that I had access to the Surface Pro Signature Type Cover detachable keyboard for punching-in shortcuts, and that the tablet features a full-size USB 3.0 port for my iLok, I saw no reason that it wouldn't be feasible. Inspired, I took to the Avid site to do some research and found its specifications are certainly in the ballpark. Now encouraged, I downloaded installers for Pro Tools, as well as the Waves Mercury bundle, and started getting down to business.

Waves Mercury - Comprehensive Audio Processing Plug-Ins Bundle

Both installations went smoothly, with no anomalies to speak of. So, I plugged my Pro Tools iLok into the USB 3.0 socket, double-clicked the familiar purple and silver icon, and was greeted by the good ol' "unable to locate hardware" error. Ah yes, I love that one. Don't we all? After a minute or two of head scratching, I remembered that I had forgotten a key step: the ASIO driver. If you've ever tried to get PT working on a Windows machine, you've probably figured out that it won't work with your native audio driver, as say, it would on a Mac using Core Audio. Luckily, there is an excellent free and widely used ASIO driver called ASIO4ALL that I could download and install on the Surface Pro in a matter of seconds. Once I did that, Pro Tools loaded right up.

Curious to see how well (or how poorly) the Surface Pro handled Pro Tools and its stock plug-ins, I proceeded to load up a demo session, a catchy Brit-rock inspired pop tune called "Turn Me Off," by the Oakland, CA, rock outfit Audrye Sessions. The mix consisted of 37 audio tracks, tons of sub-mixes and parallel buses, 2 virtual instruments, and quite a bit of processing using Avid plug-ins, such as Channel Strip, D-Verb, AIR Verb, Boom, Structure Free, and others.

To my delight, the Surface Pro could play back the 44.1-kHz session without a hitch with the Pro Tools playback engine set to a 7GB cache size, ignore errors not checked, delay compensation checked, and sample hardware buffer size set to 512. For readers who may not know, hardware buffer is a setting in the Pro Tools playback engine that effectively balances system latency with the amount of time the computer allows itself to process audio. So, the lower the H/W buffer, the more responsive the system is, but the more strain there is on the computer to keep up. For mixing in general, it's usually recommended to raise the buffer size to allow the computer more time for effects processing. However, I wanted to see how well the Surface Pro performed under more strenuous, lower-latency conditions, so for testing purposes I bumped the H/W buffer down to 128. Surprisingly, it still performed extremely well, with no overload errors whatsoever. Also, note I could easily push the cache up to 7GB, thanks to the 16GB of memory provided by this version of the Surface Pro. Higher cache settings improve disk performance, minimizing playback errors. What’s more, is that the 16GB of RAM, along with the huge, fast 1TB SSD, also makes the tablet capable of running and storing a fair amount of multi-layer sample-based virtual instruments. This further builds the case for the Surface Pro as a formidable option for music and audio production. Anyway, I digress. Back to the demo.

The mix already had a bit of volume automation on the lead vocal track, but I was excited to try adding some of my own automation using the included Surface Pen, which seemed like it would be a natural marriage. I picked one of the more lead-like guitar parts and drew some gradual panning movement as the hook section progressed, using the pen. In freehand mode with the pencil tool selected, drawing volume breakpoints on the touchscreen with the Surface Pen proved to be a fun, efficient, and accurate method for creating automation. Furthermore, I found that using the pen to draw boosts, notches, and roll-offs in the paragraphic EQ section of the Channel Strip plug-in was also quite useful and cool. Since the faders show up a bit small on the Surface Pro touchscreen, it was tricky using my fingertips to manipulate track volume in the Pro Tools mix window. Using the pen to do this was a much smoother experience, allowing me to make far more accurate and precise adjustments.

At this point, I was fairly impressed with the Surface Pro, but I was anxious to try out some of my go-to Waves plug-ins, to create a more realistic mix scenario, and to put the device to the test using some effects that are a bit more demanding in terms of processing power. First, I added the Waves V-Comp to the vocal group to level it out, and created an instance of the IR1 convolution reverb (full-power version, not efficient) on a separate bus, and sent the vocals to it for more ambience. I followed the reverb with the 6-band Renaissance EQ to cut some of the low end, and applied the MaxxBass plug-in to the DI bass guitar to give it more girth. The Surface Pro handled all the processing without a problem, with no adjustments to the playback engine needed.


Before printing, I decided to add a quick mastering chain to the mix bus, just for fun, starting with the stock Avid Trim plug-in, followed by the Waves C4 multiband compressor and then the L2 Ultramaximizer peak limiter. The L2 and the C4 are two of the more CPU-demanding Waves plug-ins, in my experience, and I was pleased to find that the Surface Pro could print the mix without any issues whatsoever.

The Surface Pro is the first tablet to come along that one could even consider calling a "legit" pro audio mixing and editing solution, if for no other reason than its laptop-strength processing power. In addition, its ability to perform well at lower hardware buffer settings makes it a viable piece for MIDI production work and maybe even audio recording, two processes in which low latency is crucial. While the Surface Pro Type Cover keyboard is on the small side and may require some getting used to in terms of ergonomics, it does make Pro Tools shortcuts and traditional mouse navigation possible, which are essential for audio editing and other tasks. Even though its relevance is somewhat limited in the Pro Tools environment, the Surface Pen did offer some useful applications that I mentioned above, such as adjusting track volume in the mix screen, as well as drawing automation and EQ curves. I also wanted to note that to authorize Pro Tools and Waves at the same time, I needed to use a USB hub. I wouldn’t call this a deal-breaker, but a second full-size USB port would have been more convenient. Overall, I was impressed with the Surface Pro, and feel that it may a represent a big step in truly bridging the gap between the mobile computing and pro audio worlds.

Microsoft Surface Pro