A great project features quality audio as well as quality video. To help to get you going, here are the basics of working with the audio features that SlingStudio offers.
Using audio sources with the SlingStudio hub Line-in Audio port
To connect an audio device to the SlingStudio hub’s Line-In Audio port, you'll need a male-male cable (often called a patch cable). This cable uses the plugs most common on portable audio devices and smartphones. You'll see several terms for patch cords that use these types of plugs: 1/8", 3.5mm, or terms with mini in them, such as mini jack or mini stereo.
Just as important as the patch cord is the audio signal that is required by the SlingStudio hub. The incoming audio signal needs to be:
- Two-channel (stereo)
- Unbalanced input
Here is what these terms mean.
You'll often hear at least a couple of audio terms using the word "level": Mic-level (which is a relatively weak audio signal) and line-level (which is an audio signal that is many times stronger than mic-level).
The SlingStudio hub’s Line-In Audio port requires a line-level (stronger) audio signal. If you connect an audio source that outputs a mic-level (weaker) audio signal then it is not likely to be audible.
Line-level audio is output by audio gear such as preamplifiers, mixers, and other signal-processing equipment. Typically the headphone jacks of computers, smartphones, or tablets output line-level audio as well.
Mic-level audio is output by a few devices, including microphones. You can use a mic-level audio device with a SlingStudio hub if you first connect the mic-level audio device to a preamplifier or a mixer, and then connect the preamplifier or mixer to the SlingStudio hub's Line-In Audio port.
Two-channel audio (also known simply as stereo sound) is well-known to many people. It provides one audio channel for the left signal, and one audio channel for the right signal. The SlingStudio hub's Line-In Audio port is designed for stereo audio inputs. If your audio source is monaural (also called mono, meaning it has one audio channel) that's fine, but make sure that you're using the correct patch cord plug so that the mono audio signal is being output over two audio channels. Some non-stereo plugs only transmit audio to one stereo channel (often the left) so audio is only heard from the left channel. Again, always be sure to test your setup before you find yourself on location with things not working as expected!
Best bet: Use a 1/8" mini-stereo patch cord that works properly with an iPhone, Android phone, iPad, or computer audio output. That kind of audio patch cord—the shorter the better, to avoid interference—works well with the SlingStudio hub.
An explanation of the differences between unbalanced and balanced inputs is outside of the scope of this article, but be aware that the SlingStudio Audio-In port requires unbalanced audio, should the matter come up with an audio device that you want to connect to your SlingStudio hub.
Also be aware that unbalanced audio connections tend to be more sensitive to electrical interference, so try to keep the audio patch cord as short as possible, ideally 10 feet or less. If you hear interference (such as a buzzing sound) in the audio, either re-route the cord away from potential sources of interference (such as computers or video monitors) and/or consider using a shorter length of audio patch cable.
Audio still not right?
Try taking a look at these things:
Sound too low?
The SlingStudio hub requires line-level input. If you've connected a microphone to your SlingStudio hub’s Line-In Audio port, the signal is likely to be extremely weak, because microphones output mic-level audio signals, which are much weaker than line-level signals. Mic-level devices must first be connected to an external audio device such as an audio pre-amplifier or an audio mixer to amplify the signal to line-level. Then connect the audio pre-amplifier or mixer to the SlingStudio hub’s Line-In Audio port.
Balanced or unbalanced?
Is the audio source that you're working with balanced or unbalanced? Remember that SlingStudio only supports line-level, two-channel, unbalanced input.
Is this new behavior?
Was there a time when these same sources worked properly? If so, then please consider: What's changed since then? You might need to reverse some recent change.
If none of these things help, then please contact SlingStudio support for more assistance.