Audio Conversion From CAT 5 to USB Detectable as input by computer?

[brenton.s.unger]

I work for the athletics center at my college, my boss wants natural/background audio for the streamed games.

Here is the current system:
The XLR microphone that detects this audio converts to a CAT 5 cable which is wired to go up to our streaming booth. This CAT 5 cable is then converted back to XLR and run through a mixer before being plugged directly into our camera which WireCast program detects the audio from the camera as an input.

What I would like to do:
I cannot change the initial conversion from XLR to CAT 5 but once it reaches its location is it possible to use an XLR to USB converter and then plug that USB directly into the computer? I need the computer to be able to detect the converted USB audio as an input so I can add that input to my Wirecast Stream.

I would appreciate the response and any help or red flags about the system would be helpful!

 

[Solandri]

XLR is balanced audio. It splits the audio signal into two, inverts one, and sends the two signals over separate wires in the XLR cable. At the other end, the inverted wire is inverted again to restore the original signal, which also inverts the noise it picked up. Then the two wires are added together. This has the effect of canceling out any noise the wires picked up along the cable run, thus eliminating (or reducing) the need for shielding the entire length of cable.

https://en.wikipedia.org/wiki/Differential_signaling

Cat 5/6 (and telephone Cat 3) work the same way - splitting, inverting, transmitting, inverting, adding to eliminate noise. That's why they're often called unshielded twisted pair. The pair of wires carry the signal and its inverse, and they're twisted to guarantee they both pick up the same external noise. So likely the Cat 5 cable run is just transmitting the raw signal from the XLR cable (it's cheaper than XLR cables for long lengths).

As for your USB device... If the USB audio converter can accept a balanced signal (typically XLR, though 1/4" phono connections can sometimes be balanced), then yes you could use it directly (provided the audio level is within the acceptable input range of the USB audio converter). I suspect however that your USB converter cannot accept a balanced audio signal. And that the mixer is performing the role of converting the balanced XLR audio signal into an unbalanced signal the USB converter will accept.

That said, baluns (balanced-to-unbalanced converters) are dirt cheap, and could replace the mixer (assuming you don't need any audio mixing). You can probably even get one that plugs straight into the Cat 5 cable, converts the balanced audio signal it's carrying into unbalanced audio (like RCA or 3.5mm headphone) which the USB converter can accept, thus eliminating the need for the Cat 5 to XLR adapter. The hard part would actually be figuring out which of the 4 twisted pairs in the Cat 5 is carrying the XLR signal. There are baluns which will convert Cat 5 into 4 audio outputs, but they're more expensive than the ones which convert to just one or two.

Or you could use the existing Cat 5 to XLR adapter, and buy a converter which goes from (balanced) XLR to (unbalanced) 3.5mm or RCA , and plug that into your USB device.

Edit: And this probably belongs in the home audio forum.