Recording Unbalanced Audio
 

Okay maybe I'm missing something really obvious, but is there a way to record unbalanced audio on the HD100? Or do I need to get a stereo DI?

I often grab an auxillary off the live audio mixer when I'm shooting live events, is this not possible without additional hardware on the HD100?

The HD100 has two channels of audio. Anything can be input into either of them as far as I understand. It's no different than any other camera.

If the source is unbalanced, you simply need a cable to go from that source to a male XLR to plug into the camera.

A DI box would only be needed if there was interfence because of the length of the unbalance run or where the unbalanced cable went. I have used a DI box near an unbalanced CD player or amp, then run a hundred feet to the camera.

But if you are close to the source and there is no interference, and the output from the board is unbalanced, just run from there into the camera.

However, if you are an an event with a professional sound setup, I would think that the output from the mixer would be balanced.

However, again, the since the camera only has two channels, if you want more channels, you would need another recorder of some kind. If the feed is high quality stereo, you might want to record that in a wav format and use the lossy camera recording (if recording in HDV) for two microphone channels.

Oh okay. 2 channels is fine, I just wasn't sure I could get away with simply using a converter cable to go from RCA to XLR without actually converting it to balanced audio first.

Actually, nothing is converted. On the unbalanced line, there just aren't the wires that would make it balanced. The signal is carried on the same wire (and there is the ground). Just try your cable first to make sure the correct pin is wired. Also, since you will probable have a line level out of the mixer, be sure the channel(s) you are using on the camera is set for this.

If you are taking stereo from the mixer, you will need a pigtail that goes from the stereo to two XLRs if you are plugging into the mixer's stereo jack.

You may have to be concerned about the impedence of the unbalanced, however.

many mixers put out a -10db unbalanced feed for consumer recorder inputs.

If your balanced inputs are pro +4db then you have a mismatch.

an adapter can correct that.

Hope this helps.

aloha,

Keith

Hi Shaun,
You can make a cable yourself if you are a bit handy with a soldering iron.
You need a male XLR and the cinch for example.
Connect pin 1 and 2 together on the XLR and connect this to the shielding of your cable and outher pin of the Cinch.
Pin 3 is then the sound signal connected to the middel pin of the Cinch

$15 at Radio Shack

1/4" female unbalanced to XLR male balanced adapter.

I've used these for years and they work fine. I also have some RCA female to XLR male, which I use to capture from the RCA outs on the BR-HD50 deck into my decklink, but I can't find them on the Radio Shack site.

Here is an article that explains the issues involved between balanced/unbalanced, high impedance (High Z)/low impedance (Low Z), and line/mic levels:
http://www.whirlwindusa.com/tech03.html

This article is a combination of both technical and easy to understand.

The best bet is to have the the different adapters, cables, connectors available for the situations that might come up in the field for the type of job being done.

I also have adapters similar to the one Tim shows that allow balanced pro mics be plugged into a miniplug unbalanced camera (ala Beachtek, but for a single channel), and allow unbalanced miniplug mics be used on a balanced XLR input.

It should be noted that the adapter Tim shows doesn't not convert the signal to a balanced signal; it only changes the impedance. If a long run is intended or there is interference, it would be necessary to use a box that actually converts the signal to balanced, and it would cost about $100 or more.

Thanks guys. I might end up just getting one of these DI20's, damn cheap (AU$50) and it can run actively on phantom power if need be. Mite be overkill for some situations (so I'll probably end up just getting some cheap adaptors too) but it's always nice having the piece you know will do the job regardless...

I am sure you will use for that. Get some adapter plugs to make sure you can get from your source to 1/4" -- Some ampls have only RCA connectors, etc. etc.