Our 24-hour Oktobercast marathon went out over a live video stream, but as an alternative the day-long podcast was simultaneously streamed through a service called Mixlr. Mixlr's audio streams--accessible on computers or mobile devices thanks to HTML 5-optimized sites and Flash playback on Android--gave listeners an opportunity to follow along for the entire 'cast and was rock solid for the entire production. So why had none of us heard of Mixlr before?
Simple answer: Mixlr's free broadcasting launched in late May 2011, and since then the service has been piling on new features--integration with Dropbox, Facebook, Soundcloud, and more. If you're looking to livestream your own podcast or broadcast audio from a special event, Mixlr's a great place to start. We'll walk you through the setup--what kind of hardware you'll need, how to get Mixlr running smoothly, and what it takes to get music and sound effects like the Inception horn integrated into the stream.
What does it take to put on a professional quality podcast? Smart editing, an interesting topic and entertaining hosts are all important, but equipment comes first and foremost. If your equipment's bad, your podcast will probably sound bad, too. Before learning how to use Mixlr, make sure you have a microphone suited to recording--but don't drop all your cash on a microphone unless you're in for a long haul. Dynamic microphones can cost in the hundreds of dollars; USB condenser microphones can be a bit more affordable.
One final concerns: think about where you're podcasting. Is it a quiet space? If not, is there anything you can do to eliminate background noise or prevent echoing? Will your Internet connection's upload speed sustain a live audio stream? Mixlr recommends minimum upload speed of 30 kilobytes per second--not too demanding, but potentially problematic for low-end DSL plans that top out around 45 kb/s up. Remember to close any unnecessary apps you have running in the background. Shutting off Twitter or an IM client might make the difference between a silky smooth stream and a poor one.
Streamin' with Mixlr
Step one: create an account. Or, rather, log in: Mixlr supports account creation via Facebook and Twitter profiles, so unless you're completely anti-social networking you probably have an account on one of those sites. And if you don't, why not create a Twitter page for your podcast? Step two: download the Mixlr client, which is available for PC and Mac users.
Setting up the app is absurdly simple: you login with the same profile you registered on Mixlr and then configure your audio settings for broadcasting. Before sending your voice out over the airwaves, though, you might want to change a few options on your Mixlr profile page. Autosharing is enabled by default, which means Mixlr will push out a notification to your Twitter/Facebook friends every time you start up a stream.
The profile page also allows you to add connections to other services for later exporting (Dropbox, Soundcloud etc. as mentioned above) and enter in the metadata for an iTunes podcast export. Mixlr will host your podcast files and serve 100 downloads per month via iTunes on a free account. If you get more popular than that, you'll have to upgrade to a premium account--but more on that once we actually get a live stream going.
A Basic Windows Configuration
Once you're logged into the Mixlr app, it gives you an option to change your audio source and an audio output to monitor how the stream sounds. At this point the type of show you're putting on comes into play. Is it just you and a microphone singing chocolate rain? Pretty easy option there--choose your microphone as the audio source. To monitor an audio source, the input and output have to be running at the same sample rate. To adjust the bitrate of audio devices in Windows, open the sound manager, right click on a device and choose Properties, and head to the Advanced tab.
Want to play sound effects, music, or multiple mic inputs? That makes things more complicated. You can go the professional route and use a real hardware mixer or download some custom software, but the simplest solution is to use Windows itself to mix your audio sources. Finding the right mixture of audio settings can be confusing, so here's the breakdown:
Under Recording Devices you should see a list that includes your microphone(s) and an entry titled Stereo Mix, which is the key to letting Windows do all the work for us. If you don't see Stereo Mix, right click and make sure Show Disabled Devices is checked. That should pull it up (if not, you probably need new audio drivers). Set Stereo Mix as the Default Device and set your mic as the Default Communications Device if it isn't already. You can look at the Properties for each and go to the Levels tab to fiddle with the mix--you'll probably want microphone volume as high as you can get it.
Now switch to the Playback tab in the Sound manager, click Properties on your Speakers and go to the Levels tab. Find the microphone input (which could be labeled something like Front Pink In, depending on where you plugged in) and unmute and raise the volume of the input. Voila--you should have microphone and computer audio coming through the Stereo Mix. Commence playing your favorite sound effects or wicked guitar licks as background audio.
Set Mixlr's audio source to Stereo Mix, enter in your title/description data and start broadcasting. Once the broadcast is going, you can Stop and Save at any time.
A Basic Mac OS X Configuration
With the Mixlr app installed, setting up a single microphone source is as easy on the Mac as it is on the PC. If you plug in a mic and find that the system is defaulting to a built-in microphone, simply go to Sound in the System Preferences and change your default (or choose the proper input in Mixlr instead).
Porting the sound from another audio application into Mixlr is also extremely easy on OS X thanks to a free program called Soundflower. Weighing in at less than a megabyte, Soundflower routes audio from one application to another through a dead simple interface. Grab it here and install, then restart your system to make sure it properly hooks into the audio settings. When you run Soundflower, the app should appear in your menu bar; settings Soundflower (2ch) to "Built-in output" will allow you to hear/monitor the Soundflower output.
Choose Soundflower as the input in Mixlr and configure your audio mixing software of choice to output its audio to Soundflower. Enter in your title/description data and start broadcasting; once the broadcast is going, you can Stop and Save at any time. To actually mix microphone and system sound into a single input for Mixlr to grab, we'll actually need a second little program called LineIn, which allows you to route input sound into an output.
With the app installed, choose your input (your USB, analog or built-in mic) from the Input from menu and put Soundflower in the Output to menu. Click Pass Thru and you'll have microphone and software sound traveling through a single audio source.
LineIn is a free solution; to really control your audio you'll probably want software dedicated to playing sound bits or queuing up different music tracks. Thankfully, there's a wealth of audio software out there for OS X. Want to use the app that instills Inception horns into This Is Only a Test on a weekly basis? Check out the free trial of Soundboard. The full app costs $50.
To Mixlr and Beyond
As soon as a Mixlr livestream is running, the app will spit out a URL you can share to let anyone listen in. If you allow the app to auto-share, it'll push out notifications to Facebook and Twitter. Mixlr widgets can be embedded in websites or Facebook pages--the service really makes it easy to get the word out about a broadcast. Mixcloud, Soundcloud, and Audioboo can all be connected to a Mixlr account to further spread recorded broadcasts.
The £4.99 monthly premium plan bumps the basic plan's 96kbps streaming quality up to 128kbps and increases the iTunes download allocation from 100 to 1000. If you're exceeding 1000 downloads per month, you probably won't have trouble hosting your podcast somewhere other than Mixlr--the real draw of the service is offering live audio streaming, after all.
There you have it--two easy ways to set up a Mixlr stream without with free software. If you're podcasting with a couple friends, investing in a real mixer will make life much easier. Believe it or not, you can get one for well under $100 that will manage enough inputs for the average 'cast.