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-   -   Screeching Static Audio Problem on XL1S (https://www.dvinfo.net/forum/canon-xl1s-xl1-watchdog/125671-screeching-static-audio-problem-xl1s.html)

Tristan Howard July 9th, 2008 11:29 PM

Screeching Static Audio Problem on XL1S
 
Hi everyone,

Lately, I’ve been dubbing a lot of VHS home video footage onto mini-DV tapes with my XL1S hooked up to a VCR. Stuff worked well for awhile and I always recorded in the “audio 1” mode, which captured sound directly from the VHS tape and not via the microphone. A few days ago, when videotaping a gopher, I carelessly recorded on easy record mode with the audio 1 settings still intact. Not long after this, I heard horrible screeching static noises when I listened to the VCR footage I transferred onto mini-DV tapes. I think recording the gopher in audio 1 mode was the main cause of my problem since I believe the mode’s only meant for external dubbing. Anyway, some of my footage sounds horribly staticy when I listen to it on headphones hooked up to my camcorder but some of that same footage also sounds fine when hooked up to Vegas 6.0 via a firewire cord. Nevertheless, later dubbed footage sounds horrible and static-filled both through headphones and through computer speakers via firewire cord. The headphones that I used had a subtly bent attachment prong (I used to trip on them a lot when they were hooked up to a TV; not proud of that; this caused violent prong disconnection and accumulated bending). So, I also think using my particular headphones could be a contributor to the problem (they’ve made the audio on my TV kind of glitchy when the headphones are not attached; left channel will have sound; right won’t; hitting the top of the TV gets sound to come out of both speakers). Still, I’ve successfully dubbed about 8 hours of footage with the headphones hooked up to my camera, so I doubt those are my main culprit.

Also, sporadically in the past, I’ve had very horrible static (similar-sounding to my current problem) show up on small portions of some of my footage. I never knew why this was and usually assumed I had accidentally flipped some switch the wrong way or knocked the mic cable connection loose (my camera gets transported often over rough terrain because of my nature work; I also often replace my live sounds, so the problem didn’t concern me much in the past; plus, I'm not proficient with the XL1S custom settings). Currently, the horrible static noise can be heard via headphones on all camera modes, including recording modes and the camera’s VCR mode. It can be heard while recording and in playback. It can also be heard in MIC audio mode and audio 1 mode. Is there a simple way for me to solve this? Should I send my camera into a Canon repair center? I don’t know. Any input would be appreciated.

Thanks,
Tristan

Don Palomaki July 10th, 2008 04:21 AM

Can you post an example in a .WAV file? Hard for me to envision the noise you are describing. Does it happen everywhere or only in some locations?

If it is intermittent and has a pulse like nature - it might even be cell phone interference.

In any case, if your headphones have a bent plug, get new headphones (or repair the plug if you have the ability). Minimize that chance of the bent plug causing other problems that could be more expensive.

Tristan Howard July 11th, 2008 08:24 AM

1 Attachment(s)
Don,

Thanks for your response. The noise seems to be continuous and not intermittent. I haven't listened to it too long because it sounds terrible. I uploaded a .wma file since it's file size is a lot smaller than a .wav file. It's is a small sampling of some problem audio from dubbed VHS footage. Yeah, continuing to use the headphones was probably pretty dumb. The plug actually appears to be mostly straight (I tried straightening it after some bending) and they're good Sennheiser phones that have served me well. Still, it's better not to take risks.

-Tristan

Don Palomaki July 14th, 2008 03:55 AM

Can't tell anything from the waveform. Pretty much static, although the right and left channel have very different waveforms in the sample you provided, with a lot of DC offset in the right channel. It sounds most like there is a loose audio cable inside.

Does recording from the built-in mic work?

Can you playback previously recorded (known good) tapes and obtain good audio output from the Audio 1 jacks?

Recording from the Audio 1 input should not make any difference or cause any specific issues. The most common problem people face faces is selecting the correct input level range.

Tristan Howard July 15th, 2008 09:09 PM

Don,

Thanks for checking out the file I posted. The recording from the built-in mic doesn’t work. Recording with a different mike attached to the camera also doesn’t work. And, recording with no mike still results in the same type of static sound. Nevertheless, good tapes still put out good audio onto my computer via a firewire cable. I can also get good sound dubbed onto a tape from my computer via firewire and successfully transfer that onto my computer. Firewire seems to be the only thing that cooperates with the sound on my camera. I tried playing back a good tape and cannot receive good audio from the Audio 1 jacks when they’re hooked up to a TV. Even on good tapes, I can also not get good audio with non-damaged headphones hooked up to my camera. I think the Audio 1 jacks might be where my main problem lies. Still, maybe there is a loose internal cable. I don’t know. I’m guessing I’ll have to send my camera into a Canon repair center for an estimate. If it is a loose cable, do you have any idea how much that might cost? Thanks a lot for your all your help, Don. I appreciate it.

-Tristan

Jack Smith July 16th, 2008 11:03 PM

Did you try the audio 2 inputs?
Select the proper settings in the menu and behind the door.
Edit: forgot to mention are you using 12bit 4 channel by chance?

Don Palomaki July 21st, 2008 06:50 PM

I have no authoritative idea as to what service might cost but in the range of $125-$400 sounds about right. As I recall, Canon will give an estimate before you authorize the work.

Does the VU meter work when you playback good tapes?

Can you put it into 4-track mode and record from the Audio 2 inputs?

Tristan Howard July 30th, 2008 10:37 PM

Hi everyone,

I did try the audio 2 inputs and that didn't change anything. I don't think I was using 12bit 4-channel. Anyway, my problem seems to be solved. Yesterday, before recording some footage, in an attempt to solve my problem, I changed the "mixed select" audio settings on the VCR menu from "variable" to "fixed" and to my surprise, my microphone picked up sound just fine again and I can even dub sound from VHS tapes fine and my headphones work fine while attached to the camera. I must have switched the settings to "variable" while initially trying to solve my problem or maybe that happened before the problem (can't remember). I'm going to assume that having "variable" set while other settings were a certain way created conflicting signals that prevented proper sound recording. Since the problem seems to be a result of my own dumb mistakes blended with ignorance, I'm apologizing to everyone I may have mislead and to everyone who's time I have unnecessarily occupied. Don and Jack, thanks for all your feedback. I hope now this thread can disappear into obscurity but if my problem comes back mysteriously, I might re-activate it.

Regards,
Tristan

Don Palomaki July 31st, 2008 04:51 AM

The setting change you describe should not cause that effect, but if the change cleared it up, great. (Might be that an internal microprocessor in the audio path got into an ill-defined state, and the change had the effect of resetting it.) May not be any reason to get it checked if you never intend to use the problematic mode.


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