Can you record podcasts on your phone?
It seems like everyone is recording a podcast these days – but can you do it on your phone and can you do it well? Darren Yates splashes $50 to find out.
In case you’ve missed it, podcasts have exploded in popularity over the last year or so. Got a particular interest? Chances are there’s now a podcast for it. But while podcasting’s popularity goes up, it seems the cost of the tech to create it has gone up, too. However, there’s also been a boom in low-cost audio recording technology, with plenty of budget microphones and mixers now on offer. The big question for me was does any of this stuff work with my phone?
Bigger than Ben Hur
Even recording a podcast just between two people can often seem like a huge production if you watch some YouTube videos. PCs, mixing desks, pricey microphones – it’s a lot of gear, which is fine if you’re in an office or fixed location. But what if you need something more portable?
We’ve long said phones are today’s true ‘personal computers’ and although most Android phones are now great at playing high-quality audio, they’re still not crash-hot at recording it. At best, you’ll find a couple of MEMS microphones in the latest phones, but rarely a bundled audio recording app in sight. So the question is: can you turn your Android phone into a portable podcasting powerhouse?
Podcasting setup
No matter how you do it, a podcast recording setup has three main components – microphones, a mixing console and a digital recording device. The microphones pick up the sound, the mixing console provides control over the audio and converts it to digital data, while the digital recording device simply records the digital stream to storage.
In our case, I wanted to use external microphones for quality and some type of mixer to do the analog-to-digital conversion (ADC) magic, but I wanted the phone to do the digital recording.
USB-OTG
One thing most Android phones costing more than $120 have in their favour is USB-OTG. USB ‘On The Go’ is a bi-directional USB port that allows you to not just plug your phone into a PC, but also plug (some) USB stuff into your phone. Another area where Android has improved is USB audio. Plug in a USB Audio Device-standard digital-toanalog converter (DAC) and you can play your music through the USB port. But we want to go the other way – we need an ADC device to pick up the microphone signal, but also be powered by the phone, be recognised by the
Android OS and also a recording app, something Android rarely includes.
Finding the right app
Google Play has a squillion apps, but we’ve only found one that does what we need and it’s called USB Audio Recorder PRO. It costs around $10, gives you a highquality audio recorder with built-in software mixer control, live stereo peak-level meters and comes with its own USB Audio Device driver support. That support covers a lot of USB devices, but as you’ll see on the website (https://www. extreamsd.com/index.php/ technology/usb-audio-driver), it doesn’t cover every possible device.
Finding a budget USB mixer
I have a pair of excellent AudioTechnica ATM10a omnidirectional condenser microphones, but nothing to plug their XLR connectors into. This is where some intuition came into play.
The key with the USB Audio Device standard is that no separate device drivers are required – just plug the device into your PC, the OS will automatically load its default driver and everyone’s happy. The problem is nothing is ever said about Android support.
A quick look on Ebay reveals there are now numerous low-cost mixers available, well under $80. The problem was I needed one that was USB-powered, had an on-board ADC (not all do) and supported two XLR-connected microphones. Without support for bus-powering or on-board ADC, there was no way this would work.
In the end, I found an Ammoon AGM02 mixer. Nice price (about $50), dual Neutrik-style XLR/jack connectors, no device drivers required, it even had phantompower for the microphones. What I still didn’t know was whether it would work with my Samsung Galaxy A30 Android phone. With no mention of Android support, I took a punt and bought it anyway, but the question remained would all this gear go together and work or just fall in a screaming heap?
Plugging it all together
The AGM02 is about the size of a 3.5-inch hard disk drive, so pretty small, but surprisingly-heavy and feels solid. With the parts on-hand, it was time to put it all together – the microphones via XLR cables into the AGM02’s two Neutrik-style XLR-combo sockets, the USB cable into the AGM02 mixer, the other end into the Type-A socket of a USB-OTG adapter and the USB-C end of that adapter into the phone.
For testing, I placed a cheap USB power meter in between the AGM02 and the USB-OTG port to measure the electrical load on the phone. With phantom-power off, the AGM02 power up and measured 20-milliamps (20mA) on the power meter. Switching on the phantom-power pushed this up to a not-unexpected 110mA.
USB Audio Recorder PRO is our favourite Android audio recorder app.
Happily, the USB Audio Recording PRO app recognised the AGM02 as a ‘USB AUDIO CODEC’ device. I hit the app’s ‘monitor’ button and the peak-level meters bounced around as I did the time-honoured count to ‘ten’. The AGM02 was even recognised as a stereo device with 44.1kHz/16-bit CD-level audio support #winning.
Drawbacks
Not everything went swimmingly, however. First, the software mixer controls on USB Audio Recorder PRO don’t support the AGM02. Still, the actual level controls on the AGM02 are better anyway. The bigger problem was the AGM02’s audio-pan controls provided minimal separation between the two channels – roughly 6dB, even when spread to extremes. The issue appears whether plugged into the phone or my Windows PC, so it wasn’t the phone or its software.
Recording quality
That was a pity because the audio quality was actually pretty reasonable – microphone input signal-to-noise ratio (SNR) of roughly 65dB, with the AGM02’s channel two-band equaliser set flat. Moreover, I wouldn’t use dynamic microphones – the AGM02’s amplification or ‘gain’ could only just push the ATM10a microphones’ output enough to hit the audio-level end-stops.
The AGM02 also supports instrument pick-ups, so I plugged in an electric guitar and successfully recorded it directly to my phone, again with decent quality. But would I use it to record a two-person podcast? Given the panning issue, only at a pinch. However, the fact that you can plug a USB audio mixer into an Android phone and record high-quality digital audio should at least open the door to finding other options available. Maybe I might even spend more than $50 next time.