The Mid Air 25-Key Wireless USB MIDI controller

FIRST IMPRESSIONS

When I first received the Mid Air 25, I tried to get it working without reading the manual or installation guide. I started ripping staples out of the side of the box (not a good idea!) before noticing that the top of the box had a carrying handle. Hopefully, you won't make the same mistake. The box contained the Keyboard controller, the wireless receiver, a DC power supply cable, a USB cable, a short installation guide, and a CD-ROM.

I was a little put off by the DC power supply cable at first. "Wireless, eh?" I thought, but then I realized that the receiver would need a power supply. So I hooked up the power supply to the receiver. I connected the receiver, via a MIDI cable, to my trusty (and relatively ancient) Roland SC-33 Sound Canvas synthesizer, connected the SC-33 to an amplifier.

The keyboad initially felt a little light, but the addition of 6 AA batteries (required for wireless operation - those electrons have to come from somewhere!) quickly cured that problem.

I powered on the keyboard and two LEDs lit up on the receiver. A green one and a blinking yellow one. I plonked on the keys and voila! Absolutely nothing, but the mysterious yellow LED kept blinking. My first instinct was to check the volume on my amp, and on the SC 33. Nope, nothing wrong there, so I checked the receiver and noticed a little switch on the side which has 3 positions. One has a little picture of a MIDI plug (the current setting), the middle position says "AUTO" and the right position has a picture of a MIDI plug with waves emanating from it, presumably waves of wireless goodness. So I switched to the rightmost setting, plonked on some keys and voila! Actual music, sans wires.

If you haven't figured it out already, the aforementioned switch is to change the input of the receiver from the wireless keyboard to a direct MIDI connection (via a supplied MIDI-in socket in the receiver). When set to "AUTO", it automatically detects which input to use, which seems to be the ideal setting.

O, WIRELESS JOY

Having the power to produce keyboard music without being connected to anything proved to be quite thrilling. I practiced spinning around on one foot while playing short little arpeggios, and it worked quite nicely, except for a bit of dizziness. Jumping up and down while playing also worked pretty well. "Damn!" I thought, "If only this baby came with a shoulder strap!" [EDIT: I am told a harness for the MidAir 25 and MidAir 37 should be made available in early 2007]

I also tried getting progressively farther away from the receiver, to see what would happen, and as expected, around 25-30 feet (depending on the obstacles), I noticed some significant latency and dropped notes. After about 30 feet, the connection gets lost altogether, and you have to walk about 10 feet closer to get it back again.

Within 30 feet, with a clear line of sight connection, the wireless connection seemed to work quite well, even the modulation wheel, pitch bend and knobs (which send far more data than the piano keys) worked apparently flawlessly.

Continuing my experiment to use the Mid Air 25 without reading the manual, I found myself able to use the Pitch Wheel, the Modulation Wheel, the Octave Shift buttons, the Sustain button (nice!) and the Program Change up/down buttons. By default, the data-entry slider worked as a MIDI volume control, which was a nice feature. When you are 20 feet away from your sound-generating hardware, it's nice to be able to turn the volume down.

I noticed that a number of the piano keys had labels printed over them, but at first, using them eluded me. I eventually figured those out with the help of the manual. These keys allow you to transpose the keyboard, assign MIDI channel, and produce custom MIDI messages, among other things.

The knobs are rubberized and have a very nice feel to them (especially compared to the thinner plastic knobs on my older Evolution Mk-425c controller). By default, the knobs controlled various features on my SoundCanvas, including the amount of reverb, and chorus effect.

Eventually I got around to connecting the Mid Air 25's receiver to my laptop, via the supplied USB cable. My PC (which runs Windows XP) was able to recognize it as a MIDI device, and there was no need to install the driver from the CD-ROM. The 25 page user manual on the CD-ROM, however, was quite useful, especially for the knob preset charts in the back.

LATENCY TESTING

The keyboard, in addition to transmitting MIDI data wirelessly, also has a MIDI-out socket in the back, so I thought it would be interesting to do a more scientific test to see if the wireless connection introduces any latency. I connected the keyboard directly to my SoundCanvas, via a MIDI cable, and then recorded the sound of me striking notes with the handle of a butter knife. The stainless steel handle produces a loud click which showed up in the subsequent recording. By examining the sound wave in Audacity (a freeware sound editor), I could measure the time between when my fingertip hit the key, and the attack of the actual sound wave produced by the SoundCanvas. I performed the same test with the wireless connection to see if there was any significant difference.

I found that in both cases the latency was virtually the same, as shown in the top two sections of this screen capture -- the beginning of the triggered sounds lines up almost perfectly. (Note that the initial delay of about 22 milliseconds is not part of the wireless latency measurement; that number includes MIDI latency, processor latency in the synth, and the time the signal needed to travel from the speaker to the microphone.)

As you can see in the bottom section of the screen capture, I was able to increase the wireless latency by about 6ms by introducing various barriers, such as encasing the receiver inside a crockpot. This latency increases even more if you get farther than 30 feet away from the receiver. I assume the extra latency is due to the need for additional error correction when there is a weak or noisy signal.

The Mid Air 25 passed the latency test. It does not exhibit any additional latency over a regular keyboard, as long as you don't push things by putting the receiver inside a crock pot.

TARGET AUDIENCE? WHAT TARGET AUDIENCE?

[UPDATE: This section has been expanded a bit for clarity.]

As an adult male with some serious gearlust, I often find that my enthusiasm for new hardware is highest just before purchasing, and then wanes after a few hours after purchase, unless the particular bit of gear is truly exceptional. I am sad to report that my enthusiasm for the Mid Air 25 followed the typical pattern -- after a few hours of wireless joy, I began to wonder what the real benefits of adding wireless capability to a MIDI controller really were.

I also began to wonder who was the ideal target user for such a beast. Bear in mind that the Mid Air 25, at $250 retail, costs about one hundred dollars more than the very similar Oxygen 8 v2 (which costs $150 retail). Basically, you are paying one hundred extra dollars for the wireless capability (plus the cost of the 6 AA batteries).

One potential target user is the keyboard or synth performer. As a standalone performance instrument, the Mid Air 25 isn't really a clear winner. It doesn't mount onto my regular rig, and it doesn't have a shoulder strap. Since my regular setup already has numerous cables, subtracting a single cable from this setup doesn't really buy me much.

I am an actual keyboard player, not a guitarist, so I prefer having a full sized keyboard that I can play with both hands, and that is what I use with my regular performance rig. I suspect that the Mid Air 25's bigger cousin, the Mid Air 37 may be a better choice for performers, especially if tricked out with a custom strap.

What about desktop musicians? I do enjoy having a small form-factor on my desktop for laying down the occasional synth track, or playing with other MIDI-controlled software. So how did the Mid Air 25 affect the workflow on my desktop?

Well, not a whole lot. There is a spot on my cluttered desk for my (previously wired) 2-octave USB MIDI controller. I took that off, and replaced it with the MidAir unit. Yes, the 2 octave keyboard no longer required a USB cable to connect it to my computer, and I could have perhaps rearranged my desk to move it farther away from my CPU. But, as it turns out, the ideal position for the musical keyboard on my desk is close to my computer keyboard (which happens to be wired) and close to my monitor (which also happens to be wired). Although I have the freedom to move the MidAir further away from the nexus of my desktop activity, the ideal place for it is actually within that same nexus, well within the reach of a wire. And let's face it -- by using the Mid Air 25 on my desktop, I haven't really eliminated a wire, I've simply moved it from the keyboard to the receiver, which is still going to sit relatively close to me, plugged into my CPU tower, taking up a USB port. So, as a desktop musician, my workflow hasn't really been significantly altered at all.

Another possible target user for a wireless MIDI controller, I think, is the performer or DJ who wishes to keep some of his gear offstage or have a less cluttered looking setup. Personally, I think having much of your gear onstage is part of the charm of electric music performance, but I suppose there are a few spartan-minded souls who will find the current crop of Mid Air products a godsend. I'm just not one of them.

THE PROS

• All the features that made the original Oxygen8 nice.
• 8 rubberized knobs with a nice feel.
• Attactive dark blue color.
• One less wire!
• Fun to play while jumping

THE CONS

• Costs $100 more than its wired cousin, the Oxygen8 v2.
• Requires 6 AA batteries.
• No shoulder strap.
• 2 Octaves only.
• Limited MIDI control options, compared to a full-sized dedicated controller.

CONCLUSION

The original Oxygen8 from M-Audio was a breakthrough product. The Mid Air 25 is more like an incremental improvement, basically adding a wireless connection to the same set of features. Is this incremental improvement worth an extra hundred dollars and 6 AA batteries? I enjoyed playing wirelessly at first, but the charm wore off quickly. Ultimately, I realized that I don't really require the extra mobility. But if you really need an additional 20 feet of distance from your equipment, than the Mid Air 25 should be well worth it.