DR-HD100 buzz in audio

[Gary Krimstein]

I've already sent it back, but if FOCUS can't find anything wrong, and hopefully they will, I will take you up on the offer. I don't believe it's the camera, because the clips played back clean through the camera.

Thanks,

Gary

[BT Corwin]

Hi Gary:

I have had a similar problem. I get a sharp "hash" sound. It is not recorded on the tape. It is only on Ch2 of the DTE. I have two DTE's and it only happens on one of them, and it happens all the time. Not at any specific interval, but it's throughout the recording here and there. And, only on Ch2. Even when there is no mic attached to Ch2.
The first time we heard it in playback (after importing the clips from the DTE into FCP) we assumed the sound was wireless mic interference.

Next time, was a quiet interview and it ruined the whole recording.
Fortunately, we were able to go back to the tape, which was perfectly clean.
Next, we switched to our other DTE. No problems. Hmmm. Back to the first DTE, same problem. Always only on Ch2.

Focus thought it was a firmware problem, and we updated the firmware.

Now, we don't get the harsh "hssss" sound, it sounds more like a bit of underwater filter.

Sent the unit into Focus (our office is very near them, so we could just drop it off) and they can find nothing wrong with it and won't replace it. So, I'm not sure what to do. I can't trust it on a shoot and Focus says they can't find anything wrong.
They said they thought it was the Anton Bauer battery/bracket that was causing it. ????? talk about passing the buck!

Btw, I have sample clips of the bad audio.

If enough people have the problem, maybe Focus will 1. realize there is a problem, and 2. figure out it out and fix it.

[Gil Whitney]

Hi all -

Anyone have any resolution with this issue? I shot some interviews with the DR-HD100, set for Quicktime HD (I had been using mt2). The client called back and told me about a low pitch whine in the audio. I shot some test footage in Quicktime HD and opened it up Quicktime - yes, it's there, but the tape is clean. I did another a test using the MT2 setting, no whine and also the tape is good. Client is using FCP 6. I shot this with a HD100 -720p 30p, DR-HD100 was set for Quicktime HD. I've tried clamps on the firewire cable, but no luck. Is this is codec issue in quicktime? Any suggestions? Thanks! -- gw

[Daniel Weber]

Gary Krimstein who originally posted regarding this problem came over this past weekend and we tested his Firestore on my HD100 to make sure it wasn't his camera causing the issue. We were able to reproduce the issue on my camera as well.

When he sent the Firestore back to Focus Enhancements they only tested it with M2T files not Quicktime. It seems like they are not worried about it, though the noise is being recorded to hard disc.

We found that it was better when we set the audio channel levels in the menu to -12db instead of the -20 that he had it at.


Gary had a shoot on Sunday that he was going to check the Firestore on again.

He will probably post here with his results.

Daniel Weber

[Giuseppe Pugliese]

Hey guys, there are a few more questions i would need to ask to better help you out...

Did you happen to record audio on both ch1 and 2? or did you record to ch1 and leave ch2 open with nothing plugged in it? (gain on open channel could be up and thus recording a grounding issue or RF signals from electronics, even your own power cables.)

A SIMPLE FIX FOR THE PROBLEM ABOVE IS THE FOLLOWING... if play back shows that your non recorded channel has the sound, in your settings you should be able to change your stereo playback to only the channel with sound and turn off the open one. You can easly check this in your NLE system by panning the audio left or right, thus cutting out one of the channels sound. If the sound leaves theres your answer. If not, continue reading haha)

What was being used to power the recorder? (again could be grounding problem)

What power source on the camera were you using at the time you were recording, was it plugged in, or running off batteries? (grounding problem)

was the mic phantom powered or not? (grounding problem)

and finally is the sound VERY high pitch, meaning high constant whistle in tone not in volume? (if so this is why you wouldn't be hearing it from the camera, the frequency response for speaker on it or the headphone you would be using to hear it played back wouldn't be able to play back that high of a frequency, thus you wouldn't hear it until played back with something that can reproduce that high of a pitch.)

Another issue could be that there isn't a high pitch recorded sound on the disk, but the disks power supply is creating that high pitch sound right when you are capturing it.

All of these are usually a grounding issue, even if its the device itself its usually a grounding issue within their device.

Let me know if any of this helps or needs further looking into.

[Gil Whitney]

Hi Giuseppe,

This was a 2 camera shoot -

Camera A (mine) was running off a battery. Firestore was powertapped in to the camera battery.

Camera B was running off a/c. Firestore was running off powertap.

Both cameras were feed ch1 & ch2 audio from a mixer (battery).

2 Lavs running off batts - no phantom.

BOTH Firestores had the high pitch whine.

BOTH tapes did not.

My recording test (just the camera and on board mic) in quicktime hd yielded the hum - in MT2 there was NO hum. Like I said in my previous post is this a quicktime issue? Anyone else with FCP 6/dr-hd100/hd100 ever have this issue? many thanks - gw

[Giuseppe Pugliese]

Originally Posted by Gil Whitney

Hi Giuseppe,

This was a 2 camera shoot -

Camera A (mine) was running off a battery. Firestore was powertapped in to the camera battery.

Camera B was running off a/c. Firestore was running off powertap.

Both cameras were feed ch1 & ch2 audio from a mixer (battery).

2 Lavs running off batts - no phantom.

BOTH Firestores had the high pitch whine.

BOTH tapes did not.

My recording test (just the camera and on board mic) in quicktime hd yielded the hum - in MT2 there was NO hum. Like I said in my previous post is this a quicktime issue? Anyone else with FCP 6/dr-hd100/hd100 ever have this issue? many thanks - gw

wow, now that is interesting, I wonder if the compression hides that specific frequency response that has the hum, or creates it. I would love to hear a clip of this noise to better help out, I've been an audio engineer for many years, so i can help just by hearing the clip to see what it could be generated from. If you can please post the audio clip in the highest resolution you can. I can monitor it on my multi ban and also listen in a acoustically tuned room, that way i can tell if this is something produced digitally via compression, or something different all together.

P.S.

There are many ways to fix this sound it post if you cant reshoot. I will be glad to try and help if you need.

[Gil Whitney]

Originally Posted by Giuseppe Pugliese

wow, now that is interesting, I wonder if the compression hides that specific frequency response that has the hum, or creates it. I would love to hear a clip of this noise to better help out, I've been an audio engineer for many years, so i can help just by hearing the clip to see what it could be generated from. If you can please post the audio clip in the highest resolution you can. I can monitor it on my multi ban and also listen in a acoustically tuned room, that way i can tell if this is something produced digitally via compression, or something different all together.

P.S.

There are many ways to fix this sound it post if you cant reshoot. I will be glad to try and help if you need.

Indeed. We are dealing with 1's and 0's so I'm not sure if grounding rules would work here. here are the files the editor sent to me. Let me know what you think. thanks -- gw

[Joseph A. Benoit]

Hello
I have a question
What mic are you using
when i use the factory mike and i turn on the Dr 100 put my head phones on
i hear a hum, turn off the Dr 100 the hum is gone
i bought a NTG-1 mike put it on the mike clamp the hum was unreal
I may be wrong but i think the mic picks up the drive noise from the
DR 100. maybe this your problem

Just a thought

JOE

[Gary Krimstein]

I feel your pain! Your audio clips show the same "noise" that I get when using my Firestore with HDV clips. I've used a variety of microphones, firewire cables, audio cables, and still get the same awful audio. You shouldn't have to jump through hoops, just to get something as basic as normal clean audio, or at least as good as the tape source. Have you had any luck with FOCUS? This shouldn't be brain surgery. Clean audio is not a minor problem with this box. It should work as advertised, and FOCUS should fix the problem.I've lost many hours of work dealing with this issue, not to mention the lost interviews and broll because the Firestore doesn't perform as it should. Maybe we just have "lemons". FOCUS should replace them, and at least let us try them with another firestore. How many others have had this problem?

Gary

[Gil Whitney]

It's real pain alright. Looks like I'll have to shoot mt2 files this weekend. The editor is going to convert them to dvcprohd files and see if that will work for him - if not, we have the tape.

I've also attached a VERY unscientific test comparing the audio of quicktime hdv files and mt2 files. I used the stock on board mic and tried to speak in the same position and volume. The results are interesting. The quicktime hdv file still has the familiar hum, but my levels seem a little low. The mt2 file on the other hand is fairly clean without the the low pitch hum, but the volume of my voice seems more robust. (but I may have been off in position or volume of my voice) I did both tests within a minute of each other - I just changed the settings on the dr-hd100.

I never notice this problem with the audio before. I had been using mt2 files up until recently, but one of my clients started using my camera package and they edit using fcp6. I'm really starting to think that this is more of quicktime issue more than anything else - BUT considering that I've only found less than 10 people complaining about the same problem, this could be a rare event, so a defective drive could be the problem.

Focus has the two audio files from my previous post, but I have yet to hear any feedback. I'll keep everyone posted. -- gw

P.S. Here are the files. They wouldn't upload.

http://www.gilwhitney.com/video/QT_hdv_audio_test.wav
http://www.gilwhitney.com/video/mt2_audio_test.wav

[Bill Parker]

I've had a similar problem. My audio is only affected during speech - at peaks. It sounds like someone bumping the mic. - but only on the clips coming into my computer in QT. It plays fine back through the camera. I'm kind of giving up on it at this point. No one seems to have an answer, least of all Focus. Maybe if $7000 drops in my lap, I can get the EX1 and be done with the firestore altogether, or use it for two shots for interviews or cutaway footage where audio isn't a concern.

[Bryan Olinger]

I ran into a "Buzz issue" this past summer with a combination of HD100, DR-HD100, and wired lav mic. We were able to hear the buzz through the headphones during the pre-interview and after problem solving discovered the buzz was linked to having the DR-HD100 plugged into A/C power while shooting. "Clamping" the wire might have solved the problem, but with the clamps not on set, we opted for the quick fix and unplugged the DR-HD100 from the wall and ran power from the Anton Bauer Gold Mount.
Just wanted to throw in some food for thought on the whole "buzz" issue. Hope Focus is able to help.

[Scott R. Smith]

I also have this problem. We have two JVC HD250 's and two DR-HD100. This happens on both cameras and both DR-HD100's. This happens no matter what the mic configuration is.

We record to tape and the DR-HD100. The tape was intended to be the backup for the drive, but with this audio problem--it's the other way around.

I understand that Focus knows about the problem, and claims to be working on it, but seems to be going nowhere as far as a solution is concerned. They recommend fixing it in post.



I read this workaround elsewhere:

"The fix is to record .m2t files and then use a program called Clipwrap to convert the files to QuickTime for use in FCP.

Google the name Clipwrap and you will find it. I think that it is around $50 or so. There is a demo that you can try. I have several friends who have been having the same issue with the audio buzz and the only work around is to record .m2t and use Clipwrap.

--Daniel Weber"


We ran a test. The audio was clean using the m2t, and we just discovered that the free MPEG Streamclip will convert the m2t to QuickTime with any codec you have installed. I hate workarounds that add extra encoding/rendering time, but this does work. What's more, you can convert the file to your favorite codec after import, then (assuming your sequence uses the same) render times should be improved for the remainder of the project.

-Scott R. Smith

[Alex Pitstra]

Originally Posted by Scott R. Smith

We ran a test. The audio was clean using the m2t, and we just discovered that the free MPEG Streamclip will convert the m2t to QuickTime with any codec you have installed. I hate workarounds that add extra encoding/rendering time, but this does work. What's more, you can convert the file to your favorite codec after import, then (assuming your sequence uses the same) render times should be improved for the remainder of the project.

-Scott R. Smith

The only real solution seems to be M2T-ClipWrap combo.
I would advice against MPEG Streamclip, because this uses re-compression instead of rewrapping. Rewrapping does not affect the original videostream.

In my experience, rewrapping the m2t's from the DR-HD100, going trough ClipWrap to a external harddisk, is very fast. Maybe only a bit slower then copying direct... No real issues with this workaround if you ask me.