The issue: I heard some distortion through my headphones while testing an X-H1 at my desk last week. I tried changing out all components but still had a niggling distortion. I even tried my two other X-H1 cameras in the same configurations; all while sitting at my desk.
I was not happy to hear the distortion and reached out for answers. Later, I used the cameras and microphones and monitors at a sound studio and did not hear the same distortion. I tried to duplicate the problem today in my living room, far away from electrical devices and was surprised when I could not duplicate the issue.
Here is my addenda to the article I wrote about the distorting monitoring circuit last week:
Edited on 04/09: Interestingly we did not have the headphone distortion problem on a shoot we did last Friday, using many of the same components. To be fair to the Fuji X-H1 I went back and re-tested again. This time I did it in my living room. Components all over my coffee table. But the times I tested the cameras before were all done at the desk in my office. I took the camera, headphones and a microphone back to the office, sat down and listened again and there was the distortion. So I started looking around my desk to see just what the heck might be causing the distortion I was hearing.
For starters my desk is the epicenter of about ten hard drives, each in their own enclosure, each with its own power supply. Then there is the 27 inch iMac about two feet from my little test area. Oh, and there's also a dual band modem/router, and, and, and...... As I moved the camera set up closer to the desk and tested it the distortion was a bit more obvious and when I moved away from the desk it diminished. And when I moved to the living room, about 30-40 feet from all electrical circuits, the microphone pre-amplifiers were as silent as mute angels.
So, this is a big mea culpa. Sometimes we imagine that technology has perfected all the routine stuff and that it will work perfectly no matter how much we try (wittingly or unwittingly) to fuck it all up. The pre-amps are a bit sensitive to huge, giant, unsavory electrical fields. Can you blame them?
I am now chastened and must send an e-mail to my friends at Fuji to apologize to them for blaming my bad technique on what I see is now a nearly perfect camera.
In addition, all the audio that we ran into three X-H1 cameras at our video shoot last Friday is perfect. Not a trace of distortion or noise.
I'm sorry to have been so far off on this and will try to be much more careful in my testing of microphone and headphone circuits in the future.
As you can see I made a bone-headed mistake and mischaracterized the performance of the camera. I am sorry for that and I also want to apologize to Fuji for unfairly dissing their camera instead of eliminating such an obvious source of interference.
Now I will never be able to say that I am without flaw again. So sad. But that's the nature of a mea culpa.
10 comments:
Sounds to me like a shielding issue. Perhaps the camera could be shielded better, but more likely you have ONE piece gear that's radiating like crazy, maybe from a lifted ground. In the old days, I'd say grab a transistor radio, and on the AM band,tune to a spot with no station, and use the radio as a sort of Geiger counter, holding it close to each item, until you identify the squawker.
Hi Kirk. My church recently replaced the lighting in the nave with LED fixtures. The quality of the light is now beautiful, but the wireless microphones have become unusable. Apparently the bulbs need some sort of shielding. I'm glad I'm not on the committee that made that decision without doing the research. You are a good person to call a penalty on yourself. Thanks. M. G. Van Drunen
Thanks for that update, Kirk. Good news. Now we are waiting to hear that you were also wrong about the camera's inability to graciously swap from one battery to another during a long take...
You're too hard on yourself. If I did that, it wouldn't even make it into the top 25 dumb mistakes in my life.
Or, to quote Roseanne Roseannadanna: “Never mind.”
One of the reasons I opt to use my MixPre whenever possible for audio capture is that it has superior RFI shielding compared to the camera itself. That said, interesting insight into the X-H1 and glad you were able to narrow down the cause of the distortion. It is definitely a hostile world these days in terms of RFI.
Hi Pixtorial, I am considering the MixPre3; I have one in my "shopping cart". Can you give us a quick impression of how you use yours and what you like about it? Especially compared to pre-amps/mixers you may have used in the past? Thanks!!!!! And yeah! Shielding. Who would have guessed?
Kirk: We've been using the MixPre3 since last June, and it has proven indispensable. There as a bit of a learning curve, especially since we use both the native mode and the musician's plugin depending on the recording scenario. The user interface, once sorted, is well thought out, plus you can easily control and monitor levels from a phone or tablet as well. The only quirk with the UI is the multi-function knob on the right side, when bagged it is a bit of a pain to reach, but it isn't a deal-breaker. I/O is pretty tight, but that is true of any small format field mixer/recorder.
My prior experience with portable recorders is mixed, I used to use Sony MiniDisc for location recording, them moved up to an HHB CD-R with a custom mic pre and large diaphragm AT mics. After that it was mostly in-camera or with a laptop based multichannel rig. I spent a lot of time weighing the MixPre3 against the Zoom F4 and F8 field recorders. I personally find the Sound Devices MixPre series to be a better build, with a superior UI and better preamps. The mic preamps are stellar, regardless of format. They are quiet, have a ton of headroom, and are wonderfully transparent with a variety of condenser mics that I've used (including shotgun, small diaphragm, and large diaphragm). Tracking workflow is straight forward, and the use of SD format cards works well for me since that is what my video workflow is based around.
There are some things to consider with the MixPre series. Power options are varied but not as straight forward as their higher end recorders. There is no Hirose power input on the MixPre3 and MixPre6. They come only with a 4 x AA battery sled, and while I've made that work I'm going to purchase the L-mount sled at some point as on the MixPre3 I max out around 2 hours on Eneloops. USB-C is an option but they are reportedly very picky about the power source (3amp USB-C battery packs don't cut it). The MIxPre3 and MixPre6 don't have internal TC generators, but in our workflow we're not often using TC so that hasn't been a deal breaker. You can push PC in through the stereo Aux input into a channel, but you lose the other channel (hasn't been an issue for how we use it). The MixPre does play nicely with the Fujifilm X-T2 and X-T3 for start-stop over HDMI.
The MIxPre3 only has XLR inputs for the three mic preamps, while the MIxPre6 and MixPre10 offer XLR/TRS combo jacks. Only really an issue if you have a need to directly punch in instruments or unbalanced line level signals.
We've done location sound for film, location sound for music events, and multitrack recording with our MixPre3 and have beeen very pleased with the results, both from a workflow and from an audio quality perspective. It definetely expands on the options you have for capturing audio in any situation.
Thanks very much for the follow up. I'm still mulling stuff over. Good to hear from someone with hands on experience!!!
So did you ever figure out what was the cause of the emf noise that the camera's headphone amp was picking up in your original experience of the problem?
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