Mopho DJ May Not Be The Most Practical DJ Setup Ever

Two turntables and a mixer to simple for you?

Then check out Mopho DJ – ‘an alternative to currently available digital hardware interfaces and time-coded vinyl (TCV)’ that’s based on modifying two turntables by taping iPod touches to their surfaces.

Here’s the official explanation:

Similar to TCV, the proposed method leverages existing analog turntables as a physical interface to manipulate the playback of digital audio. To do so, however, an accelerometer/gyroscope–equipped smart phone is firmly attached to a modified record, placed on a turntable, and used to sense a performers movement, resulting in a wireless sensing-based scratching method. The accelerometer and gyroscope data is wirelessly transmitted to a computer to manipulate the digital audio playback in real-time.

The method provides the benefit of digital audio and storage, requires minimal additional hardware, accommodates familiar proprioceptive feedback, and allows a single interface to control both digital and analog audio. In addition, the proposed method provides numerous additional benefits including real-time graphical display, multi-touch interaction, and untethered performance (e.g “air-scratching”).

Such a method turns a vinyl record into an interactive surface and enhances traditional scratching performance, while affording new and creative musical interactions.

Informal testing show this approach to be viable, responsive, and robust.

Before you dismiss this as iCrap, note that this is an academic proof of concept project, using iPod touches as cheap, ‘canned’ devices to transmit position and motion data wirelessly.

via harmonicvol

7 thoughts on “Mopho DJ May Not Be The Most Practical DJ Setup Ever

  1. I'm so glad Stanford is using their $180,000 NSF subgrant (Award 0855758 Sub-award S7039-G1) to research and develop such useful prototypes.

    Seriously though, any of the 32 citations Bryan and Wang make in their paper (4 pages of paper, 2 pages of references) would be a better read. Interaction would make or break the use of gyroscopes in this manner, and they acknowledge that they didn't even have a DJ test this. Imbecilic.

    The first reference points to Ms Pinky. Ms Pinky doesn't require any "extra" hardware beyond a TCV LP, actually has usable software and is a product you can purchase for practically nothing! And let's think about where the "vinyl" metaphor breaks down with Bryan and Wang's "research"; first of all it's a system which can't read absolute position data. You can drop the needle 2 minutes in on timecoded vinyl and your digital file/Ableton clip/automation/whatever will start playing at the 2 minute mark. Good luck accomplishing that by polling a gyroscope. Ms Pinky TCV has 155 position stamps per rotation. That's not half bad, and I even sometimes use it to modulate and "scratch" as if the vinyl were a huge super-LFO. Don't even get me started on the exponential motion scaling curves… My point here is that TCV is mature and affordable. Hell, CDJs with spinning platters are mature too.

    Forget all that for a second and tell me that you think NSF grant money should be used to figure out the best way to measure the position and velocity of a spinning platter, and that a gyroscope in a $300 phone sitting on a custom machined plexiglass disc is even worth considering..

  2. Well, Stanford eats $90,000 of that grant up front as overhead – it pays for things like libraries and the rest of the music department.

    Since tuition and expenses run about $50K per year, the remainder of the money won't even support two grad students for a single year.

  3. I'm playing the world's smallest violin for them… And publishing my research about controlling a robotic micro-violin-playing arm with a gestural smartphone interface!!! Eat it up, techblogs!

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