Voxkit -- sound-triggered MIDI drum controller for iOS

[fessaboy]

Folks -- I thought I'd post a note here that we've released a new app -- it listens to audio coming in, and can convert that into drum hits (either samples that are internal to the app, or MIDI). We're using an FFT to analyze the sound; the app can distinguish between four (distinctive) sounds. I normally drum onto the back of a book to trigger the bass, a plastic sheet for a snare, and a bottle for a cymbal, but you can train it for whatever you want. You can also beat-box a drum track.

There are four banks, each with four trigger sounds -- so you can switch quickly between different samples or MIDI note assignments. You can add your own drum hit samples (WAV file format) with iTunes file sharing. The app will also record drum samples and MIDI that you play; you can import a backing track using Audio Paste, record a drum track, and then export the drums with Audio Copy for mixing. The MIDI and recorded audio are both available through iTunes file sharing or by email -- so you can import things into Logic or ProTools.

The latency is around 15ms for playing the samples. With wired MIDI, it's around 30ms, which should be good enough for anything but very fast playing. If you're using WiFI MIDI, the latency may be annoying -- which is why we've made the MIDI recording available through iTunes.

Here's a YouTube video:
And the link to iTunes: http://itunes.apple.com/us/app/voxkit!/ ... ?ls=1&mt=8
The app is intro-priced at $0.99 for a few more days.

Give me a yell if you have any questions!

Patrick/Secret Base Design

[marlow]

Patrick,

I really like voxkit! I had purchased tabledrum probably over a year ago and was disappointed that I couldn't add my own samples or trigger midi. Voxkit does!

I haven't found the time to really play with it fully, but it seems to differentiate sounds pretty well and the latency is useable.

However, it seemed that it acted monophonic. Can two samples be triggered at the same time? I haven't tested midi to determine if the engine is tracking simultaneous triggers, but the samples do not seem to play at the same time.

Thanks,

Marlow

[fessaboy]

Only one sample can be triggered at a time with sound input; this is something that we might be able to tweak in a future version. There's a short (1/40th of a second) lock-out on audio re-triggering; without it, you can get a lot of double-hits from room echo. 40 beats per second seems like it should be enough for everyone (640k RAM, too!).

The app is looking at the frequency spectrum of the incoming sound (and actually, only about 512 samples of a volume spike at 44.1khz, to keep the latency down) -- the fingerprinting then goes with the best match from the training input. If there are two simultaneous sounds, the overlapping frequency spectrums are a harder to pick apart -- and this really increases the chance of triggering the wrong sample. We might add a switch to the next version that will let you choose how to trigger -- you could get simultaneous hits, but it would almost certainly degrade accuracy.

If you use the touch screen, you can trigger multiple hits simultaneously. The internal sampler engine supports playback of up to 10 hits at a time. There's no limit on the number that you can trigger by MIDI.