Capturing Audio And MIDI On The Cheap

Welcome to the drum nerd’s guide to harnessing the advanced capabilities of the iPhone, iPod touch, and iPad – iOS devices – to make them part of the music-production world. Because they represent new technologies, both their capabilities and limitations are not yet widely understood. Frankly, as I began to pen this article I believed I had a firm grasp on the subtleties of using them as music-production tools, only to find that, indeed, I did not. It was a great learning experience, albeit one fraught with a few sleepless nights staring at the ceiling wondering what I had gotten myself into. By the end, I hope you have a better understanding of how to fold these amazing little devices into your musical life.

Sheer Numbers

Although estimates differ, well over 200 million Apple iOS devices have shipped since the release of the iPhone in mid-2007 and the iPad in April 2010. That’s not even factoring in the 70-plus million units of the iPod touch sold, which has many of the same capabilities of the iPhone – speaker, microphone, Wi-Fi, etc. – just no cellular network capabilities. That’s about 300 million devices in users’ hands. These sheer numbers make it likely that many of you reading this article own one or more iOS devices. So, why not tap into the power of the iOS to make music? Its sophistication will allow you do a great deal more than just update your Facebook status or ignore that call from your boss.

Get ready and hang on, we’re about to dive into how to get MIDI and audio to interface with your cool iOS device, as well as explore some of the great, inexpensive software I’ve discovered that brings music production to the palm of your hand.

iOS MIDI: The Ins And The Outs

CoreMIDI is the protocol that Apple has created to handle communication between iOS devices and external MIDI instruments. iOS 4.3 (released in March 2011) or newer is required to use external MIDI with the iPhone, iPod touch*, or iPad.

Getting MIDI into iOS devices is by far the most confusing part of this whole process. The newness of the CoreMIDI spec and the tight power-consumption limitations of iOS devices, coupled with the widely varying power requirements and design differences of third-party USB MIDI devices, make finding what will function properly a bit of a minefield.

External USB devices have to connect to the iPad by the USB-to-30-pin adapter found in the Apple camera connection kit. You’ll only know if a particular USB MIDI interface works by plugging it in and seeing if the iPad prompts you that it’s either not compatible or it draws too much power. If you don’t get a prompt you’re probably in luck. I have an old Edirol MIDI interface that works great, and one of the current Roland interfaces that doesn’t work at all – go figure. There is no consistency whatsoever.

Notice that I just spoke specifically about the iPad. The camera connection kit is not designed to work with the iPhone. So if you have an iPhone, don’t waste your money on this accessory; it’s not an option.

Fig. 1. iRig MIDI Interface

A solution to this confusing mess is to avoid a USB MIDI interface entirely. Line 6 and IK Multimedia each make a MIDI interface that is specifically designed to work with iOS devices – the MIDI Mobilizer II and the iRig MIDI, respectively. They both street for around $70 and work with the iPad, iPhone, and iPod touch. Along with having a MIDI thru port, the iRig MIDI has the option of being powered by an external USB charger, which also keeps the iOS device charged. (Fig. 1)


iOS Audio: Can You Hear Me Now?

There are a number of simple devices that use the headphone jack to input line-level audio to an iOS device with a mike input. I have the iRig from IK Multimedia. In addition to the mono 1/4" analog input, it has a stereo headphone output that allows audio monitoring using headphones or speakers. Although marketed for guitars, it will also accept any line-level audio, making it great for electronic drums and percussion. Also, if you have the iRig, you can download the free AmpliTube app that lets you easily record audio through the line input. (Fig. 2)

Fig. 2. iRig and the free AmpliTube app

If you happen to have a self-powered lav or camcorder mike, I found a great little cable from kV Connection that allows you to attach these mikes, if they have an 1/8" connector, to any iOS device. This adapter incorporates passive components that provide DC blocking and isolation, as well as impedance matching. If you already have a suitable mike, this is a great option to capture high-quality sound. Search the web for “KM-iPhone-2trs” if you want to get one.

If you want an upgrade in sound quality, move from analog to digital. (Audio interfaces that use the headphone input are analog. Those that use the 30-pin dock connector are digital.) The Line 6 Mobile In is one such digital audio interface. It works with iOS devices that accept digital input on the 30-pin dock connector, like the iPhone 4 and iPad. Because it uses CoreAudio, it’s compatible with apps like GarageBand. Another advantage is that, along with the mono guitar input, it also has a stereo input, allowing you to capture a stereo output from your electronic drums. Stereo is better.

Whereas older iPhone models allowed for analog sound to be input using the 30-pin connector, the iPhone 4/4S and iPad require a digital-audio interface. The Tascam iM2 is a popular mike for the iPhone 4/4S and the iPad. It attaches using the 30-pin connector.

If you have an iPad, Apple’s camera-connection kit allows many USB devices, including USB mikes, to be connected to the 30-pin dock. Although, as with MIDI interfaces, not all mikes will be compatible. I have a Samson C03U USB condenser mike that I’ve used in the past for mobile podcasting, and it works perfectly. Samson also makes the less-expensive C01U that doesn’t have switchable mike patterns.

Enter The Alesis iO Dock For iPad

Fig. 3. Alesis iO Dock

Okay, here’s the deal, if you have an iPad get the Alesis iO Dock. It single-handedly does away with the majority of the audio and MIDI interface confusion of the iOS world. Also, once you start adding up the costs of MIDI and digital audio interfaces, you’ve pretty much paid for the iO Dock. It works with both the iPad and iPad 2 (there’s a clever adapter that slides in to make the iPad 2 fit the dock perfectly). For under $200 you get MIDI in and out, USB MIDI (to connect to a computer), and selectable mike/line Neutrik-style XLR/1/4" inputs (stereo) with phantom power. These inputs allow you to capture the output from any microphone or line-level output. There is also a headphone out, as well as separate stereo outputs for monitoring via speakers. The iO Dock turns the iPad into a little digital audio workstation.

The iO Dock even charges the iPad while it’s docked. Hey, Alesis, with all this, where’s the “make me a latte” option, huh? The only negative with the iO Dock is that you’ll need to have power where you’re working, because it doesn’t run on batteries. For real, if you’re a musician and own an iPad or iPad 2, you need to get the iO Dock. It rocks! (Fig. 3)

Software: The Coolness Begins

Most of the software I’m going to write about is compatible with all iOS devices that accept audio input and MIDI input, and are running at least iOS 4.3 or newer. That said, make sure you check out the iOS device requirements for specific software.

Except for GarageBand, I have only picked DAW software that is able to both receive MIDI and/or audio input and easily allow for the exporting of this data, so that it can be used in other applications. The most common three ways to export data are: email, iTunes sharing, and FTP over Wi-Fi. There isn’t a great deal of consistency between apps, but all discussed will export data in some useful manner.

Email Sharing
This is a very straightforward way to share. You select the file, enter a valid email address, and press send.

iTunes Sync
This is, for me, a bit of a cumbersome method of sharing. You must connect the iOS device to you computer, select the app in iTunes, then retrieve the file from a folder associated with the app.

Wi-Fi Sharing
This method uses a computer with a compatible Web browser to share the file in an FTP-style manner. With both computer and iOS device logged onto the same Wi-Fi source, you open the Web browser, enter the supplied IP address, and the folders with the app’s data appear in the browser window. From here you can copy the needed file to your computer (PC or Mac) and, in some instances, copy a file to the iOS device.


Capturing Only MIDI

Fig. 4. Line 6 MIDI Memo

If you’ve bought the MIDI Mobilizer II or iRig MIDI interfaces, you can download and use the company’s proprietary apps, MIDI Memo or iRig MIDI, to capture MIDI in real time. The apps are very similar in function, and you must use the app from the company that made your MIDI interface, as they act as dongles. The great news is that these apps are free! The MIDI input can be of any kind, including real-time performance and SysEx data. Both are universal iOS apps, so they run on both the iPhone and iPad. (Fig. 4)

As far as exporting files is concerned, iRig MIDI allows files to be exported by email, iTunes sharing, and Wi-Fi, while MIDI Memo only allows files to be emailed.

One cool use for these MIDI-capture apps is to capture MIDI performances from electronic drums. While listening to the metronome and sounds from the drum module, play a beat and record the MIDI into one of these programs. If you put the performance tempo into the name of the file, it’s easy to sync up and edit in a full-featured sequencing program. Use this method to capture beats and become a little loop factory.

iOS In DAW-land

You might have guessed by now that I’m a big fan of Apple’s iOS devices – since I first had my hands on the Apple Newton 100 in 1993. Since then I’ve been searching and not so patiently waiting for the perfect handheld device. This device would perform any task I asked of it, including music. I’m not just talking about having it play back music for listening purposes; I’m talking about having it help me create music. Well, my wait is over. There is now a digital audio workstation that fits in the palm of your hand. Is it perfect? No, but it’s pretty darn cool.

Two ofthe best multitrack iOS DAWs out there are the Meteor Multitrack Recorder from 4 Pockets and Apple’s GarageBand. Each have different strengths and capabilities that set them apart from the other DAW apps.

Meteor Multitrack Recorder

Fig. 5. 4 Pockets’ Meteor Multitrack Recorder Track View window

This 12-track iOS DAW for the iPad (not available for the iPhone) closely mimics the features and functionality of its computer-based brethren. Being limited to 12 tracks, which can be any combination of audio or MIDI tracks, isn’t that much of a concern, especially when you remind yourself that it’s running on iPad. The bonus is that each of the audio tracks can be either mono or stereo, in effect doubling your audio track count. (Fig. 5)

Fig. 6. 4 Pockets’ Meteor Multitrack Recorder Audio Editing window

A surprising number of tools for editing audio files come standard with Meteor. Included are ones you would expect, like fade in, fade out, and normalization. Surprisingly, more advanced tools like time stretch, pitch shift, and even beat detection are included in this sub-$20 app. (Fig. 6)

Stereo delay, stereo reverb, and tone boost effects come standard. They can be routed just as they would be in the physical world: to a master bus, aux send, and insert bus, as well as be applied to audio as it is being recorded. Did I mention it’s less than 20 bucks?

Fig. 7. 4 Pockets’ Meteor Multitrack Recorder MIDI editing window

MIDI editing is done through a standard-looking piano-roll layout. This $7.99 in-app purchase is well worth the money. It functions just like a computer-based system. (Fig. 7)

Although it is possible to export MIDI Tracks, from what I can tell Meteor mixes down all the MIDI tracks into one file. So, if you want to export a single MIDI track it should be the only MIDI track in the project file. MIDI-file export is handled by local network FTP. Open any computer Web browser, enter the supplied server and port information, and a list of files and folders will appear. MIDI files are found in the Export folder.

Individual audio files for each track can also be exported and shared using FTP, just like MIDI files. Audio can also be exported as a finished mix in most of the common file formats. Overall, this is a very powerful app, and I can’t wait to explore it further.


Apple’s GarageBand

Fig. 8. GarageBand Track window

It’s $4.99 in the Apple app store. I mean, really, that’s the cost of a bottle of water at the NAMM show. The user interface is amazingly elegant, and in true Apple tradition, very intuitive. It accepts MIDI and audio input from all the devices previously mentioned, but runs a bit slow on my first-gen iPad when using Alesis iO Dock. Perhaps it’ll run better on iPad 2. Running GarageBand out of the dock greatly improves its performance. (Fig. 8)

Fig. 9. GarageBand Smart Guitar window

You can create tracks using the “Smart” instruments, which even made me a little bit of a guitar player, which I’m not, or input your performance from an external MIDI instrument, like electronic drums. I hooked up my electronic drums to GarageBand with a MIDI interface and immediately was able to trigger one of the virtual drum sets. It was so easy. GarageBand, which runs on the iPad and the iPhone, makes creating music fun. It’s probably the best five bucks I’ve ever spent. (Figs. 9 and 10)

Fig. 10. GarageBand Drum Kit window.

On the downside, you can only export your project as either an audio file or a GarageBand file. The latter you can open up in GarageBand on a Mac, thereby unleashing more powerful editing and production tools. If you want to capture and export a MIDI file, you’re out of luck. (There is a workaround for this using a program called midiO once you have the project running in GarageBand on a Mac, but it’s kind of cumbersome.) Perhaps Apple will allow for the export of MIDI files in a future version. 

If you have any questions, concerns, rants, or diatribes about this article, feel free to contact Mike Snyder directly through his Web site at