PDA

View Full Version : Mobile Audio Recording with Raspberry Pi?




Prodo123
Aug 1, 2013, 05:37 PM
Hi,

First of all I apologize for the irrelevance. This has little to do with Macs, although Linux is a Unix-like system I suppose.

I film movies for a lot of personal projects, and I was hit with a big equipment failure. The XLR in 1 of my primary mobile recorder, the Zoom H4, doesn't work anymore. I tried all the contacts, the circuitry, etc. and couldn't find the short. (if anyone has an idea as to how to fix this feel free)

Then I had an idea. Since the Raspberry Pi is so small and has USB ports, why not use it as a mobile recorder with my USB audio interfaces? I thought about the idea, and for it to work I'd need the following:

1. A real-time clock with the Raspberry Pi for proper time codes
2. A battery and a big SD card for prolonged mobile use
3. Maybe a keyboard or remote of some sort to initiate recording
4. A suitable program that can do multi-track, multi-interface recording at 24/96, and automatically save it as a separate file whenever the recording stops
5. A case to store the Pi (I'd be carrying the entire setup in something like a backpack)

This would effectively give me an expandable, mobile-enough recorder with high quality audio and timestamps for under $120. Audio monitoring would be enabled by routing all audio out to one of the audio interfaces. Since I have 2 2-input interfaces, I'd be getting a Linux-powered 4-track recorder.

Of course not many people have tried such a thing, and I was wondering how feasible this even sounds. Is it even doable?

To give an example of what one would look like with this setup, here's a visual simulation.
http://www.samruby.com/Entertainment/Wallpaper/doc_1024.jpg



steve-p
Aug 2, 2013, 03:04 AM
It sounds to me like a lot of trouble to go to to replicate what an iPad running Auria with a supported USB multichannel audio interface will do 10x better. I realise your idea is a lot cheaper, but it's also a lot less effective, unsupported and probably less reliable.

Prodo123
Aug 2, 2013, 03:36 AM
It sounds to me like a lot of trouble to go to to replicate what an iPad running Auria with a supported USB multichannel audio interface will do 10x better. I realise your idea is a lot cheaper, but it's also a lot less effective, unsupported and probably less reliable.

Yes, but the thing is I need multiple interfaces that require a lot of power each, esp. for phantom power. The iPad also has limited storage, another downside.
I don't know if something like the M-Audio FTP is supported on the iPad, but I do know for sure that it's supported on Linux.

steve-p
Aug 2, 2013, 05:13 PM
I don't know if something like the M-Audio FTP is supported on the iPad, but I do know for sure that it's supported on Linux.
I believe it is, although you would also need the camera connection kit and a powered USB hub I expect.

localoid
Aug 2, 2013, 07:48 PM
If you're trying to put together a decent mobile DAW on the cheap then your best bet would be to buy a used/refurbished 10" Netbook w/Windows XP, a new 6-cell battery (for the Netbook), along with a USB audio interface. Then install a lean Linux distro on the netbook (such as Lubuntu). Total cost: ~$200 (assuming you shop the used market.)

The Raspberry Pi is cheap but it has become outdated when compared to what's on the market today as far as mini-PCs-on-a-stick are concerned. Plus, you'd need to come up with a pretty beefy battery power source to run a mini-pc plus run a USB interface with phantom power, probably in the 3-5amp @ 5v range, which isn't going to be cheap.

To tell what you were doing on the Pi, you'd also need a battery-powered HDMI monitor, plus at least a touch-pad controller (or a keyboard w/built-in touch-pad) to control it, both of which would require even more portable battery-power.

You could easily end up investing hundreds of dollars in a system that may or may not ever work reliably.

Either a netbook (or other small laptop that could run 6+ hours) or a tablet (either a high-end Android* or an Apple iPad) paired with a decent USB audio interface would be a far more reliable solution.

* If you want to do =>4 channels @ 96k with an Android you're going to need one with a Qualcomm XPeria S or XPeria Z, or Samsung Exynos processor.

ChrisA
Aug 3, 2013, 09:18 PM
You could run Apple's Garage Band of a $125 re-furbished iPad touch. But really, real PC hardware is cheap a sub $200 notebook would work better.

localoid
Aug 3, 2013, 11:14 PM
You could run Apple's Garage Band of a $125 re-furbished iPad touch. But really, real PC hardware is cheap a sub $200 notebook would work better.

The trick with an iPad would be finding a USB audio interface that's fully compatible that would provide phantom-power, to power mics, that didn't require a powered USB hub.

The ART USB Dual Pre, which runs about 75, can supposed do this (w/iPad at least), but its max is only 16-bit/48k.

The Apogee ONE, at $350, can do so, and it is 24 bit/96kHz.

Dunno... There may be others audio interfaces that are known to work that are in a price range somewhere between those two. Anyone here know?

Or, one could build a home-brew battery-powered USB hub, or try running a stock powered-hub from something like the Tekkeon power pack (http://www.adorama.com/TEMP1580.html?gclid=CK-3tIv24rgCFShp7Aod3CQAPg).

Vroem
Aug 22, 2013, 10:57 AM
Until now, you could do

iPad
USB audio interface

but now

iPhone
iOS 7 beta
USB audio interface

seems to be the new option.

More info here:
http://www.native-instruments.com/forum/showthread.php?t=197120

ChrisA
Aug 22, 2013, 12:48 PM
Hi,

1. A real-time clock with the Raspberry Pi for proper time codes
2. A battery and a big SD card for prolonged mobile use
3. Maybe a keyboard or remote of some sort to initiate recording
4. A suitable program that can do multi-track, multi-interface recording at 24/96, and automatically save it as a separate file whenever the recording stops
5. A case to store the Pi (I'd be carrying the entire setup in something like a backpack)

Wow a home build notebook PC. Why bother when you can buy an old "netbook" on eBay for $100? These already have screens and keyboards and SD slots and you can run Linus or BSD on them. It's actually cheaper and more reliable.

For recording the big thing is always the audio interface. A four channel USB interface with good preamps and XLR connecters. Maybe a Presonus or MOTU unit is what you need if you can't afford a "real" field recorder.

Or just send in the Zoom recorder to have it repaired.

Prodo123
Aug 23, 2013, 12:01 AM
Wow a home build notebook PC. Why bother when you can buy an old "netbook" on eBay for $100? These already have screens and keyboards and SD slots and you can run Linus or BSD on them. It's actually cheaper and more reliable.

For recording the big thing is always the audio interface. A four channel USB interface with good preamps and XLR connecters. Maybe a Presonus or MOTU unit is what you need if you can't afford a "real" field recorder.

Or just send in the Zoom recorder to have it repaired.

The Zoom repair would cost more than the netbook xD
Thanks for the feedback, everyone.