Making music on Android

Apple’s iPad quickly became the de-facto portable studio for musicians, thanks to the ever-popular GarageBand app, but your Android device could well be equally capable of fulfilling your creative streak.

Whether it’s capturing LPs, guitar, keyboard, MIDI, drums or straight voice, Android devices typically support far more audio capture devices than just the internal microphone.

Here, we’re looking at what you can musically achieve through your favourite Android device — and you don’t need Marshmallow/Android 6.0.x inside.

In fact, you’ll need as little as a USB-OTG port and Ice Cream Sandwich/Android 4.0.3.

Recording LPs to Android

atlpVinyl is making something of a comeback as retro tech is rediscovered and younger users jaw-drop over sound from a groove and stylus.

You may have seen the raft of new vinyl turntables hitting discount department stores, some as low as $50 and including USB connectivity.

Relax, we’re not recommending you pull out pristine Beatles LPs for a $50 turntable. However, if you’ve got the vinyl bug and are ready to buy a turntable, we’d suggest starting with something like an Audio-Technica AT-LP60 that’ll give you decent quality without wrecking the budget.

But if you want to capture vinyl to your phone, it’s easy to do, just learn some basics first.

The mechanics of turntables are pretty simple — a phono cartridge, containing the needle or ‘stylus’, wobbles around in the vinyl groove, the lateral movement of that stylus creates proportional AC voltages via two magnet and wire coil sets, one for each audio channel.

However, the audio signal has two issues — first, it’s so tiny, you can’t just plug it into your PC sound card as it won’t pick it up. Second, vinyl LPs are recorded using a particular frequency response that boosts the upper frequencies and cuts the lower ones to overcome vinyl’s mechanical limitations.

Low-frequency tones need a wider groove deviation, which cuts down recording time, but by recording the base sounds at a lower level and boosting them in playback, the groove is narrower, allowing longer running time.

To correct this ‘RIAA equalisation curve’ for playback, the audio must be fed through a ‘phono preamp’, reversing the RIAA frequency response curve and restoring the original audio. Otherwise, it’ll sound like someone’s cranked up the treble flat-stick.

Cheap turntables usually have an RIAA/phono preamp built-in, mid-range models such as the AT-LP60 make it switchable (so you can use your own RIAA preamp if you wish), while top-drawer models mostly don’t bother with one, since they expect you’ll use your own anyway.

If your turntable does have a built-in preamp, switch it on and you’ll have a signal you can feed straight into your USB sound card’s line-in socket.

proTo get the audio into your Android device, you just need a USB audio adapter your device can talk to and a recording app to capture it. Our go-to app for this is USB Audio Recorder PRO — it has built-in USB audio support and runs on almost any Android device with at least Ice Cream Sandwich (4.0) and USB-OTG connectivity.

We’ve talked about this app previously, testing it successfully with a range of USB audio adapters, including Creative Labs’ old Sound Blaster Extigy and Audigy 2 NX boxes, producing excellent sound quality.

In recent weeks, we’ve tried a budget C-Media CM106 7.1-channel USB adapter purchased from eBay, on which you can record good-quality line-level audio via USB Audio Recorder PRO, but the app’s mixer sliders have no effect here — the CM106 is locked on max recording levels, although typically, that’s not a problem.

Still, the signal-to-noise ratio (SNR) is about 70dBFS, and although vinyl won’t give much more than that, we’d recommend a higher-quality USB audio adapter with a lower noise floor (see here for a compatibility list).

Recording guitar to Android

lesI can pick up a guitar and play chords, but I’ll admit I know just enough about guitar playing to be dangerous.

The electronics behind guitars, namely combo amps and amp heads, are more my style — and that helps you learn about guitar audio fast.

Any guitar-head will tell you the gods of rock are Fender and Gibson, the two US companies that revolutionised solid- body electric guitar design in the 1950s.

usbForgetting the ‘shape’, what gives these guitars their unique tone are their pickups under the strings — Fender guitars, for the most part, use multiple single-coil pickups, whereas Gibson use double-winding ‘Humbucker’ pickups.

Humbucker pickups generally deliver higher output levels than single-coil pickups, but that aside, the output range can vary between 75 millivolts (75mV) to 1,000 millivolts (1V), depending on the design.

Humbuckers get their name from the double counter-wound coils that cancel out 50Hz AC mains ‘hum’ (they ‘buck the hum’), leaving you with clean, comparatively hum-free tone.

From the pickup coils, you can plug your axe into a no-distortion, no-effects ‘clean’ channel for pristine guitar audio, or into an audio effects board and trick up the sound.

linkBut once it’s plugged in, that guitar signal output is typically line-level — again, you just need a compatible USB audio adapter and USB Audio Recorder PRO to record the audio directly into your Android device.

The key to capture quality now is the analog chain from the pickups, through the cable to your USB sound card — once that audio is in digital form along the USB cable, your Android device just has to capture the digital stream.

From that point, it doesn’t matter whether you have a Galaxy S7 or a $50 Android tablet from the local supermarket — they’ll both capture it with the same quality.

One low-cost audio option we saw recently was this USB Guitar Link — USB Type-A connector on one end, quarter-inch headphone socket and quarter-inch guitar cable socket on the other.

It’s powered by USB and has a thumbwheel rotary headphone volume control on one side and a high/low gain switch on the other to cater for different pickup output levels as we mentioned earlier.

bossA quick test showed SNR of about 60–65dBFS with recording level set to minimum, 45dBFS at maximum. We tried this on our Android 6.0.1/Galaxy S3 frankenphone — USB Audio Recorder PRO recognised the device and we were able to record straight from guitar at either 44.1 or 48kHz/16-bit sampling. Not too bad for $10, including shipping.

Still, to do your skills justice, go for a quality USB audio adapter — either plug in your guitar direct or take the output from your effects board. But according to USB Audio Recorder PRO’s compatibility list, the app also supports BOSS’s ME25 stompbox via USB-OTG straight into your Android device, although we are yet to confirm this.

Recording MIDI to Android

Musical Instrument Digital Interface or MIDI has been around since the 1980s and, despite the arrival of USB, is still the preferred option for musical keyboards.

If your MIDI keyboard has its own sound module, you can just plug the line-level output into a USB sound card and record the output into your Android device, as with guitar audio.

But you can also record just the MIDI signals themselves into sequencing software on your Android device, essentially creating digital music.

There are a couple of ways to do this. First, you can use MIDI-over-USB, where you grab a low-cost MIDI-to-USB adapter and a sequencing app, such as n-Track Studio Multitrack DAW to record the MIDI tracks.

A more recent option supported by Marshmallow/Android 6.0 is ‘Wireless MIDI’ or MIDI over BLE (Bluetooth Low Energy). As of time of writing, this spec was still in draft mode, but it works similarly to any other Bluetooth device — pair up, link it with your sequencing software and away you go.

You can read more about Apple’s BLE MIDI spec at the Apple Developers’ website or Android.

Google even added MIDI support to its Chrome browser mid-way through 2015 and it looks as though, from user forums and Google’s own developer site, that Wireless MIDI is working on Android 6.0.

yamWe’re also interested in Yamaha’s brand-new MD-BT01 wireless MIDI interface. For now, the official Yamaha word on Android support is ‘no’, but that may change.

A word of caution, however — if you read the above Android Developers’ page on MIDI, you’ll see that MIDI-over-USB requires an additional kernel configuration, meaning that it needs to be enabled in Android’s Linux kernel when the OS for your particular device was originally compiled.

Unfortunately, it’s not part of the ‘android-base’ configuration and must be manually added by device manufacturers.

It’s not difficult — it just needs:

CONFIG_SND_USB_MIDI=y

…added to the kernel configuration file prior to compiling.

If you’re using BLE-MIDI, this isn’t a problem.

What does it all mean in practice? Basically, Android supports MIDI over USB, but it needs to be baked into your device’s Android OS.

If you’re running a custom ROM, chances are more likely it’ll be turned on, but either way, stock or custom, the only way to know for sure is to suck it and see.

Record microphone to Android

Yes, yes, we know Android devices come with a built-in microphone, but you wouldn’t stake your reputation on its quality.

Not surprisingly, there are bucketloads of USB microphones available and a decent number of them work on Android.

Just off the bat, we can think of four different ways you can do it.

miniFirst, there’s the USB microphone built into the one module — these start at $2 for something that looks like a tiny Bluetooth USB dongle, right through to Rode’s NT-USB condenser microphones for studio-grade sound.

Second, use a dedicated microphone preamp to generate line-level audio from a standard mic and feed that into your Android-ready sound card, as you would audio from guitar or vinyl.

Third, most USB sound cards have built-in microphone preamps to allow connecting your microphone via the same box to your Android device.

And finally, the fourth option is an XLR-to-USB microphone link cable. This gives you a three-pin XLR microphone plug on one end and a USB Type-A plug on the other. Inside the cable is an integrated analog-to-digital converter and USB module.

This may allow you to use any self-powered microphone in your kit bag, either dynamic or battery-powered condenser type (such as Audio-Technica’s old ATM10a pencil mic).

rodeStill, USB microphones can be a mixed bag and, as you’d expect, the cheaper you go, the worse the quality.

The XLR-USB cable we bought also turned out to be quite modest in performance (we suspected it might be, but took one for the team anyway).

My personal preference is to always start with the best quality microphones you can afford and worry about how you capture that audio later. If the source audio is rubbish, the rest is a waste of time.

But then, which type of microphone should you choose — condenser or dynamic? Every smartphone and tablet has a condenser microphone inside, but again, it’s not usually straight from the top drawer.

Studio-quality condenser mics deliver a much higher output level than dynamic mics, due in part to built-in preamp circuitry. USB microphones also have that circuitry and obtain power from the USB cable, but a USB mic will rarely match a studio-grade condenser for quality.

As a result of the internal circuitry, studio condenser microphones also usually require ‘phantom-power’ — anything up to 48VDC — on the signal line. A dedicated preamp or mixing console can provide this before the analog audio can be split off to your Android device.

Condensers can also be brittle — you don’t ever drop a condenser mic. In the studio, they’re fine, but on the road, they need kid-gloves. Not that you should drop-kick dynamic mics across the stage, either, but at least they’ll take a bit more rough treatment than condensers.

The other thing is that dynamic mics have no electronics inside, just the transducer (coil and magnet assembly) picking up the sound, meaning they can usually handle a much higher sound pressure level (SPL), for example, up close to a kick-drum, than condensers.

So in short, it’s horses for courses.

Line-level rules

In the end, it comes down to this — you can record any analog audio source onto your Android device at very high quality provided you can get it into a line-level signal first.

Further, the more devices in the analog audio chain, the greater the background noise you’ll hear (and lower the SNR and overall quality).

But really, no matter what your musical taste, whether it’s listening, recording or creating, there’s no need to leave your Android device out of the loop — it’s actually a hell of a lot better than you might think.