Audio cable for GH2

[Ron German]

I need some tips (links, prefebly B&H / Adorama) on audio cable to use pro mics with my new GH2:
XLR female to 2,5mm male (I gess).
Thanks

[Ben Giles]

Ron. You'll need to either run a box that will convert a balanced mic feed (XLR) from your "pro" mic to an unbalanced mic input on your GH2 - eg Juiced Link, Beachtek boxes etc.

Or you can short-cut the eventual realisation that it's most likely more hassle than it's worth and run separate audio into a digital recorder (eg Tascam DR100 or Zoom H2N etc) and sync with your video rushes in the edit - if you have loads of rushes, you might want to consider an NLE plugin called Plural Eyes. If not, just clap your hands in front of the camera and sync it up the tried and tested old-fashioned way.

Ben.

[Ron German]

Thank you Ben
I have a Zoom 4HN already, but when I have to work alone or (and) quick, I need a straight solution, like a convert cable, but it`s not easy finding a 2,5mm male to XLR female cable, unlike 3,5mm.

[Bill Bruner]

Ron - what I do is run a Sescom impedance matching cable from my Zoom's headphone out to the GH2's mic in. That way, I can run my XLR mics into the Zoom, run the headphone out into the GH2, and then record tracks on both devices. That way, I have both an in-camera track and a backup track.

You can either get the cable with a 2.5mm jack, especially made for the GH2, or get it with a 3.5mm jack and use a 3.5mm to 2.5mm adapter to plug into the camera (that's what I do, in case I ever want to switch back to Canon or Nikon ;-)).

Hope this is helpful,

Bill
Hybrid Camera Revolution

[Mark Slade]

+1 on the Sescom cable

[Ben Giles]

I may have missed the point here, but (I think) Ron is talking about running a cable directly from his mic to the GH2:

"it`s not easy finding a 2,5mm male to XLR female cable"

The Sescom cables just provide a pad from the line-level/headphone output of the Zoom down to a mic level that won't overload the GH2. The cables are very short and rely on running a high level line signal down the cable and dropping it through resistors right at the end within the shell of the 2.5mm jack plug - that way, there is only a tiny path of vulnerable low-level unbalanced microphone signal between the 2.5mm jack shell and the pre-amp within the GH2.

If you're happy to use your Zoom as your mic pre-amp/mixer/line-level converter, then stop reading right now and buy a Sescom cable.

But Ron, if I'm correct in thinking you want to bypass the Zoom and plug your mic directly into your GH2, I'm afraid you're up against one of the principle reasons DSLRs haven't killed off regular video cameras - you can't plug balanced microphone signals directly into them. Keep reading and I'll try my best to explain in the least amount of words I can.

Balanced microphone signals are very low and rely on an op amp at the source end and target end. Any noise picked up along the route by the earth (wrapped around the 2 signal cables) is phase-cancelled out at the target end. It's been around since the 1950s and it's very effective. In modern digital terms, think of it like a Dolby encoder at the source and a decoder at the target end.

Your pro mic with an XLR output is designed to send balanced audio this way. If you want to plug it directly into the GH2, you're going to need an op amp to "decode" the balanced signal, output an unbalanced mic level at an impedance that will suit the GH2 and keep that final unbalanced signal path as short as possible - because it's very vulnerable to picking up RF noise. At the same time, you'll probably want the ability to regulate the levels from the mic and monitor it through headphones, whilst keeping pre-amp noise to a minimum.

And that's the raison d'être of the Beachtek or Juiced Link boxes (and whatever else there is out there to compete.)

There are lots of reviews and opinions on those out on the web - I should think you'll be able to come up with a shortlist fairly quickly.

The advantage over the Zoom/Sescom combo is that these units bolt directly to the underside if the GH2 and effectively turn it into the nearest thing to a DSLR with proper unbalanced mic inputs. Otherwise, save some money and use your Zoom as the pre-amp and use some kind of magic arm or clamp to keep it near the GH2.

The difference is essentially an ergonomic one - but it's a crucial difference in practise, when you need ease of use, speed, resilience and reliability.

At which point, I would refer you to my earlier opinion about it being more hassle than it's worth. I have a Sescom cable, I've used it once with my DR100 as the pre-amp/mixer and I found the whole combo too vulnerable and unwieldy.

Hope all of that makes sense. Congratulations for reading this far...

Ben.

[Ron German]

Thank you very much Ben, Mark and Bill. Much appreciated explanation.
Yes Ben, I wanted to bypass the Zoom and plug the mic directly into my GH2.
But at this moment, I gess the most viable solution is using the Zoom H4N, even not being straighfoward as I need.
By the way, Isn`t the Sescom cable too short? How I would handle both camera and Zoom with a 9 inch cable connecting them?

[Ben Giles]

As I said, it's short because it's vulnerable to RF - any longer and you'll be picking up local taxis and baby intercoms.

So, ergonomically you're stuck with the Zoom close to the GH2 and good luck with trying to find a way of making it work for you.

Ben.

[Don Litten]

Ben is right...good luck.

My feeling is that camera audio is always sub standard and an H4N on the rig is still subject to thumps and bumps that ruin the sound.

My approach is to use the H4N's (I have more than one) as close to the subject as possible, sometimes with, sometimes without a mic, and sync to the camera later using Plural or Duel eyes (depending on what NLE I'm using.

The camera audio is to sync to and as a redundant backup.

[Ron German]

Ok, thank you. There is not A ideal solution.

[Bill Bruner]

Ben - I mount the recorder on the camera's hot shoe to keep it within 9 inches of the mic jack using one of these. Here is a picture:

https://lh3.googleusercontent.com/-Q...4/S1010004.JPG

Hope this is helpful,

Bill
Hybrid Camera Revolution

[Ben Giles]

Thanks Bill.

Cool if it works for you but, for me, I suspect that kind of top-heavy contraption would be dead within a couple of shoots. And, if you're using that DR100 with it's built in mics, the handling noise/microphony must be significant, as you've got nothing on there to acoustically decouple it.

In the example you've got there, where you're running what looks like unbalanced mic-level radio feeds into the DR100, surely you'd be better off keeping all of that in a separate bag - or even just left somewhere static doing it's job?

To me, that all looks like a highly vulnerable accident waiting to happen.

Ben.

[Bill Bruner]

Understand your concern - it does require some thought when setting up shots, but it has worked for me so far! No handling noise and no disasters. I guess I'll just have to make do with this "Frankenrig" until someone comes up with a <$2000 large sensor camcorder with interchangeable lenses and XLR inputs :-)

Cheers,

Bill

[Hugh Raggett]

Take a look at this link - it might be helpful:
AT875R mic phantom powered directly by the GH2 - Personal View Talks