BKO Radio Commentary: Podcast Tech

This post is probably more for my benefit (and long-term record-keeping) than yours – but if you are at all interested in the behind-the-scenes, technical aspects of the show, feel free to read on.  The purpose of this post is to describe a recent problem I was having with some of my audio equipment, how I chose to solve it, and what my current “studio” setup looks like.

Ever since I started podcasting, with a variety of partners on a variety of mediums, recording quality audio has been a challenge.  After all, I am one guy on a very limited budget producing shows out of his spare bedroom.  I don’t have access to the high-end equipment of a radio studio, nor even the engineering know-how to get everything right on the first try.

Those things being said, I do have a background in radio production from my college years, I have a very solid (though not exhaustive) understanding of how computer hardware and software works, and when I began, I had a small collection of basic audio equipment.  Put these things together in any setup, really, and you probably have enough for a pass-able, OK-sounding podcast.  And we did.

Most recently, (from about late November 2011 to early January 2012), I’ve been dealing with some inexplicable and frustrating equipment failure.  This is bound to happen when you have a “studio” built on extremely low-cost hardware (all of my equipment, other than computers, was purchased for less than $100 per item, and most for less than $50).  It took me about 4 hours to troubleshoot and isolate the source of the failure, and about a week of occasional contemplating and browsing on Amazon before deciding what I could do to solve the problem.

Let me begin with a list of my hardware:

It’s probably also useful to know my goals and standard practice for recording a podcast:
  • My co-hosts connect with me over the Internet, via Skype or Google Hangout
  • Ideally, I would like to share a variety of audio sources with my co-hosts, to give an “in-studio” feel; software/sound drivers generally do not allow this
  • I record and edit the show using the free, open-source audio editor, Audacity
  • The show is usually streamed on UStream

So with all of that out of the way, let’s move on to the problem:

My Behringer USB sound card stopped working correctly; the right channel on the analog input simply up and quit in late November.  The basic setup I had been working with for the better part of a year was:

  • Behringer is hooked up to laptop, running Windows 7
  • Take LINE OUT from mixing board to analog INPUT on Behringer; this source becomes the “microphone” for Skype on laptop
  • LINE OUT from Behringer contains the analog sources from mixer PLUS any audio from laptop (including Skype), via USB.  This source connects to LINE IN on desktop PC
  • I could listen to all audio sources by plugging into the headphone jack on the Behringer

In practice, this setup was reasonably effective.  I could play a music bed or sample of a song on the CD player (which connected to the mixing board), and my co-host would be able to hear it.  However, there were some drawbacks: (1) any sound played from the laptop (maybe a YouTube video or a sound file) would make it into my final recorded mix, but co-hosts couldn’t hear it, (2) it required that I have two computers – one to host the Skype call, one to serve as the “record deck.”

When the analog right channel on my Behringer stopped working, my production was fouled up in a couple ways.  A stereo recording in Audacity would capture the L-R for any sound coming through the USB bus on the Behringer from my laptop (so the co-hosts audio, plus anything played from laptop), but my own voice and any analog source from the mixer only came through the left.  Playing a song from the CD player that made use of a dynamic stereo sound was lost in this case, and it was also more annoying than you would think to hear myself coming through only one side of my headphones.  The editing process also became more painful, as I would record in stereo, then copy the entire program to a new mono track in Audacity, before pasting back to a new stereo mix that duplicated my voice in both channels (I later realized I could simply record in mono on Audacity and save a step).

Once I figured out that the problem with losing the right channel was in the Behringer analog input, I became mentally hung up on the fact that the DIGITAL output should still work just fine.  Of course, you can see that this line of thinking was off to begin with, because even a digital out from that device would still carry only the left analog channel (the problem was with the INPUT).

In any case, I would up searching for and finding a USB sound card with digital (i.e., S/PDIF) in AND out, as well as traditional 1/8″ analog plugs.  The Sewell was a reasonably good buy at under $30, but my final setup makes no use of the digital capabilities of any of my sound cards.

I should take a moment here to mention the importance of sound drivers with any complex audio setup that you want to do with your PC.  With all three sound devices (the on-board, and the two USBs), Windows can employ a generic driver to get *something* out of them.  However, in order to access all of the functionality that I would need, I had to seek out the latest available drivers for each device.  That is generally an easy process, but it should always be Step One.  Coming from an analog background in radio studios of the late 90s and early 2000s, I can attest to the fact that you can bang your head against a wall for hours wondering why your signal flow isn’t happening the way you expect, when the problem is likely the software responsible for making your devices work…

OK, so with a new piece of equipment in my wheelhouse (the Sewell SoundBox), I was ready to find the ideal solution:

  • With the number of devices and PCs at my disposal, I decided that settling for duplication of the setup I had before was unacceptable
  • I wanted my co-hosts to be able to hear ALL sound sources from my studio (PC, CD, my voice, and anything else I want to plug in to the mixer)
  • I wanted to eliminate the need for two computers — I figured that with three sound cards and a mixer, there must be some way I could accomplish producing the show on one machine
  • I wanted to make this setup work in either Windows 7 or Ubuntu (my preferred OS), but would settle for one or the other

It took me four or five hours of thinking, cable re-routing, and testing to get everything to work the way I wanted, but in the end, I was happy with my final setup:

  • All three audio devices are plugged in and enabled in Windows 7
  • My microphone, CD player, and misc other analog sources are plugged into the mixing board
  • In Windows 7, I use the Behringer UCA202 as the “Default Speakers” – this source then carries any sound that I want to play from the PC (except Skype, but we’ll get to that)
  • The analog LINE OUT from Behringer goes to an Auxillary IN on the mixing board – so now I have all my analog sources PLUS the PC coming through the mixer
  • The AMP OUT from the mixing board goes to LINE IN on the Sewell
  • In Skype, I choose LINE IN from the Sewell as my “microphone” source, allowing me to send ANY sound from the mixer over the web to my co-hosts
  • In Skype, I choose the LINE OUT on the Sewell for Speakers – now I’ve picked up my co-hosts’ audio in addition to everything else*
  • LINE OUT from the Sewell goes to LINE IN for the on-board sound on the PC
  • On-board LINE IN is chosen as the record source in Audacity
  • On-board LINE OUT comes through my desktop speakers/headphones, so I can monitor the entire production at once
  • I was only able to make this work in Windows 7; with further testing, I might be able to get it to go on Ubuntu as well
  • I have tested all my audio sources, and I can capture them all in the final mix in Audacity

The BryGuy Show on January 8 will be the first one to use the new audio setup, but I’m really excited to have the entire studio functioning the way I’ve wanted since the start.  I’m also VERY glad that I was able to get this working using just one PC.  Not only does that simplify my personal interface with the production, but it also means that I could put together a watered-down version of this setup for use on the road with my laptop as the PC audio source/Skype machine, and my Tascam DR-07 MK II as the record deck.

Happy listening… I know that I’m going to be more satisfied with my setup going forward.

* – This was one of my big stumbling blocks in getting things set to go – in Windows 7, if you try to enable “listen to this device” on a LINE IN source, you’re going to get a fraction of a second of latency, and it’s enough to make your brain (not to mention your recording software) very angry.  I also found that I was barking up the wrong tree trying to use the venerable old Stereo Mix somewhere in the equation.  If you have the right drivers for your audio device, you should see three tabs on the Properties menu of your “Speakers” playback device that carries the full audio that you want to push out to your record deck:

Look at the “Levels” tab and you hopefully have controls for speaker volume on top, but also LINE IN and MICROPHONE volume below:

The Line-In is generally muted by default.  If you un-mute, it behaves like a regular analog audio pass-through, and you can “hear” all your other sources piping through, with zero latency.  This was essential to my final setup, or I wouldn’t have been able to get the full mix that I wanted in Audacity.